Michael D. Dake was born in South Bend, Indiana and received his undergraduate degree at Harvard College where he was elected First Class Marshall, Class of 1973. Subsequently, he graduated from the Baylor College of Medicine in Houston where he completed an internship, residency, and chief residency year in internal medicine before moving west.

The year following his fellowship, he worked at San Francisco General Hospital before moving to Miami in 1988 to join Barry T. Katzen, the year after he founded the Miami Vascular Institute. In 1990, Dr. Dake returned to California to assume the positions of Section Chief of Cardiovascular and Interventional Radiology at Stanford University School of Medicine and Co-director of the Catheterization and Angiography Laboratories at Stanford University Hospital. In addition to pioneering work in the area of stents for the treatment of venous obstruction and the earliest literature contributions in the field of CT angiography, the Stanford group under the leadership of Dr. Dake performed a number of medical firsts.
The most enduring reputation of Stanford Interventional Radiology is the sustained development of endovascular procedures for the management of a variety of aortic diseases. Blessed by supportive relationships with talented surgeons from a department with a long celebrated history of excellence in the operative treatment of cardiovascular diseases, the interventional radiology section under Dr. Dake’s leadership acquired extensive clinical experience with endovascular procedures for the management of ischemic complications related to branch vessel involvement with aortic dissection, while in the animal laboratory they were exploring innovative techniques to treat the aortic lesions in acute type B dissection. The novelty of these approaches soon gained the attention of those in the field with interests in acute aortic syndromes.

In January 2005, Dr. Dake assumed the role of Chairman of the Department of Radiology and the Harrison Distinguished Medical Teaching Professor of Radiology at the University of Virginia Health System. In addition, he held professorial appointments in the Department of Medicine (Pulmonary Diseases) and Surgery at the School of Medicine in Charlottesville. During his tenure, he led the development of a new research facility for the Department with the construction of the Snyder Translational Research Building at the Fontaine Research Park. Dr. Dake served as a member of the Market Strategy Committee of the Health System, the Clinical Chairs Committee of the Health Services Foundation, and the Clinical Services Executive Committee.

In the fall of 2008, Dr. Dake returned to Stanford where he is Professor of Cardiothoracic Surgery and Director of the Catheterization and Angiography Laboratories at Stanford Medical Center. He and his wife, Barbara, have three daughters and a son.

Clinical Focus

  • Diagnostic Radiology
  • Interventional Radiology
  • Endovascular Surgery

Academic Appointments

Administrative Appointments

  • Thelma and Henry Doelger Professor (III), Stanford University School of Medicine (2008 - Present)
  • Medical Director, Catheterization and Angiography Laboratories (2008 - Present)

Honors & Awards

  • First Class Marshall, Harvard College (1973)
  • Elmer Ng, M.D. Award: Outstanding Resident in Diagnostic Radiology, University of California, San Francisco (1986)
  • Fellow, Council on Cardiovascular Radiology, American Heart Association (1990)
  • Scientific Exhibit Award, Magna Cum Laude., RSNA (1992)
  • The Dotter Memorial Lecture, The Western Angiographic and Interventional Society Annual Meeting (1992)
  • Scientific Paper Award, Cum Laude., Society of Computed Body Tomography and Magnetic Resonance (1993)
  • Scientific Programme Award, Outstanding Medal., European Congress of Radiology (1993)
  • Scientific Exhibit Award, Cum Laude., European Congress of Radiology (1993)
  • Scientific Exhibit Award, Summa Cum Laude., RSNA (1993)
  • Scientific Paper Award, Cum Laude, Society of Computed Body Tomography and Magnetic Resonance (1994)
  • Honorary Membership, Rocky Mountain Radiological Society (1995)
  • California Vascular Institute Distinguishe Lectureship, The California Vascular Institute (1995)
  • Howard James Ricketts, M.D. Memorial Lecture, Department of Radiology, Unitversity of Washington (1995)
  • Honorary Membership, The Maine Vascular Society (1996)
  • Scientific Exhibit Award, Certificate of Merit, RSNA (1996)
  • John McAffee Lecture, Department of Radiology, University Hospital, State, University of New York Health Science Center (1997)
  • American President’s Award, Roentgen Ray Society (1998)
  • Young Investigator Award (mentor), Society of Cardiovascular and Interventional Radiology Gary J. Becker (1999)
  • Houndsfield Award, Society of Computed Body Tomography and Magnetic Resonance (1999)
  • George W. Holmes Lecture, The New England Roentgen Ray Society (1999)
  • Charles T. Dotter Memorial Lecture, American Heart Association (1999)
  • Resident Research Trainee Prize (mentor), Radiological Society of North America (1999)
  • Charles J. Tegtmeyer Lecture, ISET (2000)
  • Wattie Fletcher Lecture, British Society of interventional Radiology (2000)
  • Sarnoff Fellowship Prize for Cardiovascular Research (mentor), Sarnoff Cardiovascular Researhc (2000)
  • Nobel Prize Nominator in Physiology or Medicine, Physiology or Medicine (2000-2002)
  • William Cook Keynote Speaker, Canadian Association of Radiologists (2001)
  • Scientific Exhibit Award, Certificate of Merit, European Congress of Radiology (2002)
  • Gary Becker Young Investigator Award (mentor), Society of Cardiovascular and Interventional Radiology (2002)
  • Gary Becker Young Investigator Award (mentor), Society of Cardiovascular and Interventional Radiology (2006)
  • The McClelland Visiting Professorship, Sutter California Pacific Medical Center (2006)
  • The Dotter Lecture, Society of Interventional Radiology (2007)
  • Eugene F. Bernstein Memorial Lectureship, Scripps Clinic Green Hospital (2007)
  • Twin Cities Vascular Lectureship, Minneapolis Heart Institute Foundation (2007)
  • Honorary Membership, The Eastern Vascular Society (2008)
  • Gary Becker Young Investigator Award (mentor). Filip Banovac - fellow, Society of Interventional Radiology (2009)

Professional Education

  • Residency:Baylor College of Medicine Registrar (1982) TX
  • Medical Education:Baylor College of Medicine Registrar (1978) TX
  • Fellowship:UCSF Medical Center (1987) CA
  • Residency:UCSF Medical Center (1986) CA
  • Board Certification: Diagnostic Radiology, American Board of Radiology (1986)
  • Board Certification: Pulmonary Disease, American Board of Internal Medicine (1986)
  • Board Certification: Internal Medicine, American Board of Internal Medicine (1981)
  • Board Certification: Vascular and Interventional Radiology, American Board of Radiology (1994)
  • Fellowship:UCSF Medical Center (1983) CA

Research & Scholarship

Current Research and Scholarly Interests

Improved endovascular procedures and devices to treat aortic lesions, peripheral arterial disease and venous abnormalities. Focused interest in drug-eluting stents and balloons, endovascular stent-grafts, including branched aortic devices and techniques for the endovascular management of aortic dissection. Current clinical research projects include drug-eluting stents for superficial femoral arterial disease and multiple device trials to evaluate stent-grafts for the treatment of aortic lesions.


2017-18 Courses


All Publications

  • Midterm survival after thoracic endovascular aortic repair in more than 10,000 Medicare patients JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Schaffer, J. M., Lingala, B., Miller, C., Woo, J., Mitchell, R. S., Dake, M. D. 2015; 149 (3): 808-820


    Aneurysms and dissections of the descending thoracic aorta represent a complex substrate with a variety of therapeutic options. The introduction of thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of thoracic aortic disease. However, longitudinal analyses of post-TEVAR outcomes appropriately stratified by aortic disease remain limited.A total of 11,996 patients undergoing TEVAR from 2005-2010 were identified from the Medicare/Centers for Medicare and Medicaid Services database. Patients were stratified by underlying aortic disease and the presence of Current Procedural Terminology (CPT) codes. Survival was assessed using Kaplan-Meier analysis. Cox proportional hazards analysis determined predictors of survival from TEVAR.After TEVAR, patients had a median survival of 57.6 months (95% confidence interval, 54.9-61.3 months). Although patients without CPT codes had significantly fewer recorded comorbidities, TEVAR survival was comparable between patients with and without CPT codes (56.3 vs 59.5 months, P = .54). The early and late incidence of death varied significantly by aortic disease. Patients with aortic rupture, acute aortic dissection, and aortic trauma had the highest early incidence of death, whereas late survival was highest in patients with acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm. Although hospital TEVAR volume was not associated with survival, an independent hospital effect (determined by using a mixed-effect Cox model) associated certain hospitals with a hazard for death 50% of what it was at other hospitals.TEVAR has been applied to a multitude of aortic diseases in the Medicare population; early and late post-TEVAR survival varies by aortic disease. The late incidence of death remains high in TEVAR recipients, although certain aortic diagnoses such as acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm were associated with improved late survival. An independent hospital effect, but not hospital volume, is correlated with post-TEVAR survival. Future analyses of TEVAR outcomes using the Medicare database should adjust for underlying aortic diagnoses and the presence of CPT codes.

    View details for DOI 10.1016/j.jtcvs.2014.10.036

    View details for Web of Science ID 000351930600052

    View details for PubMedID 25541408

  • Cheese wire fenestration of a chronic juxtarenal dissection flap to facilitate proximal neck fixation during EVAR. Annals of vascular surgery Ullery, B. W., Chandra, V., Dake, M., Lee, J. T. 2015; 29 (1): 124 e1-5


    To describe successful endovascular repair of a complex chronic aortoiliac dissection facilitated by a unique endovascular fenestration technique at the proximal neck.A 57-year-old man presented with disabling lower extremity claudication and a remote history of medically treated type B aortic dissection. Computed tomographic angiography demonstrated a complex dissection with 7.1-cm false lumen aneurysmal dilatation and significant true lumen compression within bilateral iliac aneurysms and no suitable proximal infrarenal neck free of dissection.Using intravascular ultrasound, guidewires were introduced into true and false lumens. A 9F sheath was placed on the right side, and a 20-ga Chiba needle was positioned at the level of the celiac artery and oriented toward the dissection flap. The needle was advanced to puncture the flap, and a 0.014-in wire was then snared from the true to the false lumen. Shearing of the dissection flap in the juxtarenal segment was performed using a "cheese wire" technique, whereby both ends of the guidewire were pulled caudally in a sawing motion down through the infrarenal neck and into the aneurysm sac. Angiography confirmed absence of residual dissection and perfusion of the visceral vessels via the true lumen. Given the newly created infrarenal neck, standard endovascular aortic repair (EVAR) was performed and antegrade and retrograde false lumen flow was obliterated from the visceral vessels. Postoperative imaging confirmed aneurysm exclusion, no endoleak, and patent bilateral common iliac arteries with resolution of claudication symptoms and normal ankle-brachial indices.Endovascular management of false lumen aneurysms in the setting of chronic dissection is limited by the ability of stent grafts to obtain adequate proximal or distal fixation. Endovascular fenestration of these chronic flaps facilitates generation of suitable landing zones, thereby serving as a useful adjunct to standard EVAR.

    View details for DOI 10.1016/j.avsg.2014.07.025

    View details for PubMedID 25192823

  • Two-Year Analysis of the Japanese Cohort From the Zilver PTX Randomized Controlled Trial Supports the Validity of Multinational Clinical Trials JOURNAL OF ENDOVASCULAR THERAPY Ohki, T., Yokoi, H., Kichikawa, K., Kimura, T., Snyder, S. A., Ragheb, A. O., O'Leary, E. E., Jaff, M. R., Ansel, G. M., Dake, M. D. 2014; 21 (5): 644-653

    View details for DOI 10.1583/14-4753.1

    View details for Web of Science ID 000343076500007

  • A novel, catheter-based approach to left ventricular assist device deactivation after myocardial recovery. Annals of thoracic surgery Zeigler, S. M., Sheikh, A. Y., Lee, P. H., Desai, J., Banerjee, D., Oyer, P., Dake, M. D., Ha, R. V. 2014; 98 (2): 710-713


    We describe a case of catheter-based embolization and deactivation of a left ventricular assist device using an Amplatzer plug for a patient demonstrating myocardial recovery after diagnosis of nonischemic cardiomyopathy. This procedure can provide a minimally invasive, low morbidity solution for patients wishing to be separated from left ventricular assist device support who want to avoid invasive surgery for device removal.

    View details for DOI 10.1016/j.athoracsur.2013.09.073

    View details for PubMedID 25087798

  • Five-year results of thoracic endovascular aortic repair with the Zenith TX2 JOURNAL OF VASCULAR SURGERY Matsumura, J. S., Melissano, G., Cambria, R. P., Dake, M. D., Mehta, S., Svensson, L. G., Moore, R. D. 2014; 60 (1): 1-10


    This trial evaluated thoracic endovascular aortic repair (TEVAR) compared with open surgical repair of descending thoracic aortic aneurysms and large ulcers at 42 international sites. Whereas several studies demonstrate early safety and utility advantages with TEVAR, longer follow-up is important because of concerns about durability of TEVAR.This prospective, nonrandomized study enrolled 160 TEVAR patients treated with the Cook Zenith TX2 and 70 open surgical repair patients.Although follow-up was limited, 5-year mortality rate was similar at 37% for both groups. Aneurysm-related mortality rate was 5.9% with TEVAR compared with 12% with open surgical repair (P = .11). There were no ruptures of the treated aneurysms in either group or open conversions in the TEVAR group. Predefined severe morbidity occurred at a significantly lower rate in TEVAR (21%) compared with open surgical repair (39%; P < .001). Aneurysm growth was seen by core laboratory in 5.9% of patients and endoleak in 5.7% of patients. Secondary intervention rates were similar between TEVAR (8%) and open surgical repair (12%; P = .49) patients.Five-year results indicate similar all-cause mortality and aneurysm-related mortality with TEVAR compared with open repair. There was a persistent reduction of severe complications with TEVAR. Reinterventions occurred with similar frequency. TEVAR with the TX2 is a safe and effective alternative to open surgical repair for the treatment of anatomically suitable descending thoracic aortic aneurysms and ulcers.

    View details for DOI 10.1016/j.jvs.2014.01.043

    View details for Web of Science ID 000338449500001

    View details for PubMedID 24636714

  • DISSECT: A New Mnemonic-based Approach to the Categorization of Aortic Dissection EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY Dake, M. D., Thompson, M., Van Sambeek, M., Vermassen, F., Morales, J. P. 2013; 46 (2): 175-190


    OBJECTIVE/BACKGROUND: Classification systems for aortic dissection provide important guides to clinical decision-making, but the relevance of traditional categorization schemes is being questioned in an era when endovascular techniques are assuming a growing role in the management of this frequently complex and catastrophic entity. In recognition of the expanding range of interventional therapies now used as alternatives to conventional treatment approaches, the Working Group on Aortic Diseases of the DEFINE Project developed a categorization system that features the specific anatomic and clinical manifestations of the disease process that are most relevant to contemporary decision-making. METHODS AND RESULTS: The DISSECT classification system is a mnemonic-based approach to the evaluation of aortic dissection. It guides clinicians through an assessment of six critical characteristics that facilitate optimal communication of the most salient details that currently influence the selection of a therapeutic option, including those findings that are key when considering an endovascular procedure, but are not taken into account by the DeBakey or Stanford categorization schemes. The six features of aortic dissection include: duration of disease; intimal tear location; size of the dissected aorta; segmental extent of aortic involvement; clinical complications of the dissection, and thrombus within the aortic false lumen. CONCLUSION: In current clinical practice, endovascular therapy is increasingly considered as an alternative to medical management or open surgical repair in select cases of type B aortic dissection. Currently, endovascular aortic repair is not used for patients with type A aortic dissection, but catheter-based techniques directed at peripheral branch vessel ischemia that may complicate type A dissection are considered valuable adjunctive interventions, when indicated. The use of a new system for categorization of aortic dissection, DISSECT, addresses the shortcomings of well-known established schemes devised more than 40 years ago, before the introduction of endovascular techniques. It will serve as a guide to support a critical analysis of contemporary therapeutic options and inform management decisions based on specific features of the disease process.

    View details for DOI 10.1016/j.ejvs.2013.04.029

    View details for Web of Science ID 000323690900005

    View details for PubMedID 23721817

  • Diagnosis and treatment planning of acute aortic emergencies using a handheld DICOM viewer. Emergency radiology Choudhri, A. F., Norton, P. T., Carr, T. M., Stone, J. R., Hagspiel, K. D., Dake, M. D. 2013; 20 (4): 267-272


    Acute aortic syndromes and traumatic aortic injury are often diagnosed on CT angiography, possibly requiring emergent intervention. Advances in handheld computing have created the possibility of viewing full DICOM datasets from a remote location. We evaluated the ability to diagnose and characterize acute aortic pathologies on CT angiograms of the thorax using an iPhone-based DICOM viewer. This study was performed after Institutional Review Board approval. Fifteen CT angiograms of the thorax in suspected acute aortic syndromes were evaluated by three blinded radiologists on a handheld device using a DICOM viewer. Studies were evaluated for the ability to identify and classify aortic dissection, transection, or intramural hematoma, measure aortic dimensions, and identify mediastinal hematoma, arch variants, and pulmonary pathology. Studies were compared to blinded interpretations on a dedicated PACS workstation. The aortic pathology was correctly identified as aortic transection/pseudoaneurysm (n = 5), type A dissection (n = 2), and type A intramural hematoma (n = 1) by all reviewers, with no false-positive interpretations. This represents a sensitivity and specificity of 100 %. Mediastinal hematoma (n = 6), pneumothorax (five right, three left), and arch vessel involvement (n = 2) were identified in all cases. There was 88.5 % accuracy in identifying arch variants. Measurement of the size of the involved aortic segment was similar on handheld device and PACS workstation; however the adjacent normal aorta was 1.2 ± 1.0 mm larger on the handheld device (p = 0.03). Handheld DICOM viewers may be useful for emergent consultations and triage, and may expedite preprocedure planning to reduce the time interval between diagnostic scan and therapeutic intervention.

    View details for DOI 10.1007/s10140-013-1118-8

    View details for PubMedID 23525945

  • Sustained Safety and Effectiveness of Paclitaxel-Eluting Stents for Femoropopliteal Lesions 2-Year Follow-Up From the Zilver PTX Randomized and Single-Arm Clinical Studies JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Dake, M. D., Ansel, G. M., Jaff, M. R., Ohki, T., Saxon, R. R., Smouse, H. B., Snyder, S. A., O'Leary, E. E., Tepe, G., Scheinert, D., Zeller, T. 2013; 61 (24): 2417-2427


    OBJECTIVE: A prospective, multinational randomized controlled trial (RCT) and a complementary single-arm study evaluated the 2-year safety and effectiveness of a paclitaxel-coated drug-eluting stent (DES) in patients with superficial femoral artery (SFA) lesions. The RCT compared the DES to percutaneous transluminal angioplasty (PTA) and provisional bare metal stent (BMS) placement. BACKGROUND: Local drug delivery for SFA lesions has been investigated with the intent of limiting restenosis similarly to DES for the coronary arteries. One-year outcomes of DES in the SFA are promising but longer-term benefits have not been established. METHODS: In the RCT, patients were randomly assigned to primary DES (n=236) or PTA (n=238). Acute PTA failure occurred in 120 patients, who underwent secondary randomization to DES (n=61) or BMS (n=59). The single-arm study enrolled 787 patients with DES treatment. RESULTS: Compared with the control group, the primary DES group demonstrated significantly superior 2-year event-free survival (86.6% versus 77.9%; p=0.02) and primary patency (74.8% versus 26.5%; p<0.01). In addition, the provisional DES group exhibited superior 2-year primary patency compared with the provisional BMS group (83.4% versus 64.1%; p<0.01) and achieved higher sustained clinical benefit (83.9% versus 68.4%; p=0.05). The 2-year freedom from target lesion revascularization with primary DES was 80.5% in the single-arm study and 86.6% in the RCT. CONCLUSIONS: The 2-year outcomes with the paclitaxel-eluting stent support its sustained safety and effectiveness in patients with femoropopliteal arterial disease, including the long-term superiority of the DES to PTA and to provisional BMS.

    View details for DOI 10.1016/j.jacc.2013.03.034

    View details for Web of Science ID 000320602200005

    View details for PubMedID 23583245

  • Catheter venography for the assessment of internal jugular veins and azygous vein: Position statement by expert panel of the International Society for Neurovascular Disease VASA-EUROPEAN JOURNAL OF VASCULAR MEDICINE Simka, M., Hubbard, D., Siddiqui, A. H., Dake, M. D., Sclafani, S. J., Al-Omari, M., Eisele, C. G., Haskal, Z. J., Ludyga, T., Milosevic, Z. V., Sievert, H., Stehling, M. K., Zapf, S., Zorc, M. 2013; 42 (3): 168-176


    This document by an expert panel of the International Society for Neurovascular Disease is aimed at presenting current technique and interpretation of catheter venography of the internal jugular veins, azygous vein and other veins draining the central nervous system. Although interventionalists agree on general rules, significant differences exist in terms of details of venographic technique and interpretations of angiographic pictures. It is also suggested that debatable findings should be investigated using multimodal diagnostics. Finally, the authors recommend that any publication on chronic cerebrospinal venous insufficiency should include detailed description of venographic technique used, to facilitate a comparison of published results in this area.

    View details for DOI 10.1024/0301-1526/a000265

    View details for Web of Science ID 000319484000004

    View details for PubMedID 23644368

  • Treatment of Femoropopliteal In-Stent Restenosis With Paclitaxel-Eluting Stents JACC-CARDIOVASCULAR INTERVENTIONS Zeller, T., Dake, M. D., Tepe, G., Brechtel, K., Noory, E., Beschorner, U., Kultgen, P. L., Rastan, A. 2013; 6 (3): 274-281


    This study sought to evaluate the outcomes of drug-eluting stent treatment for femoropopliteal in-stent restenosis (ISR).ISR after femoropopliteal interventions is an increasing problem. Although the role of drug-eluting stents in the treatment of coronary ISR is well defined, no published studies have examined drug-eluting stents in the treatment of femoropopliteal ISR.This study examines 108 patients with 119 ISR lesions who were enrolled in the ZILVER-PTX single-arm study, a prospective, multicenter clinical trial of 787 patients. All patients were treated with paclitaxel-eluting nitinol stents.Mean patient age was 68.3 ± 9.4 years; 61.1% of patients were men. Mean lesion length was 133.0 ± 91.7 mm; 33.6% of lesions were >150 mm long and 31.1% of lesions were totally occluded. Procedural success was achieved in 98.2% of lesions with 2.1 ± 1.2 stents placed per lesion. Primary patency was 95.7% at 6 months and 78.8% at 1 year. Freedom from target lesion revascularization was 96.2% at 6 months, 81.0% at 1 year, and 60.8% at 2 years. Forty patients experienced major adverse events, exclusively target lesion revascularization. Before treatment, 81.1% of patients had Rutherford scores ≥3; at 2 years, 60.9% of patients had Rutherford scores ≤1. Both ankle brachial index and walking impairment questionnaire scores significantly improved following treatment. The 1-year fracture rate of stents used in ISR lesions was 1.2%. No significant risk factors associated with loss of patency were identified.Treatment of femoropopliteal ISR with paclitaxel-eluting stents results in favorable acute, midterm, and long-term outcomes. (Zilver PTX Global Registry [ZILVER-PTX]; NCT01094678).

    View details for DOI 10.1016/j.jcin.2012.12.118

    View details for Web of Science ID 000317485300013

    View details for PubMedID 23517839

  • Innovative Solutions: An Axiom of Interventional Radiology JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Dake, M. D. 2012; 23 (10): 1335-1336

    View details for DOI 10.1016/j.jvir.2012.08.005

    View details for Web of Science ID 000309484900016

    View details for PubMedID 22999753

  • Extracranial Venous Drainage Patterns in Patients with Multiple Sclerosis and Healthy Controls AMERICAN JOURNAL OF NEURORADIOLOGY McTaggart, R. A., Fischbein, N. J., Elkins, C. J., Hsiao, A., Cutalo, M. J., Rosenberg, J., Dake, M. D., Zaharchuk, G. 2012; 33 (8): 1615-1620


    CCSVI hypothesizes an association between impaired extracranial venous drainage and MS. Published sonographic criteria for CCSVI are controversial, and no MR imaging data exist to support the CCSVI hypothesis. Our purpose was to evaluate possible differences in the extracranial venous drainage of MS and healthy controls using both TOF and contrast-enhanced TRICKS MRV.Healthy subjects (n = 20) and patients with MS (n = 19) underwent axial 2D-TOF neck MRV (to assess flattening) and TRICKS MRV (to assess collaterals) at 3T. Two neuroradiologists blinded to cohort status scored IJV flattening and the severity of non-IJV collaterals by using a 4-point qualitative scale (normal = 0, mild = 1, moderate = 2, severe = 3). κ was used to assess reader agreement. Comparisons between groups were performed by using the Wilcoxon rank sum test. The Spearman rank correlation was used to assess the relationship between IJV flattening and collateral scores and, in patients with MS, EDSS scores.The 2 groups were matched for age and sex (MS, 45 ± 8 years, 79% female; healthy controls, 47 ± 10 years, 65% female). Reader agreement for IJV flattening and collateral severity was good (κ = 0.74) and moderate (κ = 0.58), respectively. While IJV flattening was seen in both patients with MS and healthy controls, scores for the patients with MS were significantly higher (P = .002). Despite a trend, there was no significant difference in collateral scores between groups (P = .063). There was a significant positive correlation between flattening and collateral scores (ρ = 0.32, P = .005) and EDSS and flattening scores (ρ = 0.45, P = .004) but not between EDSS and collateral scores (ρ = 0.01, P = .97).These results indicate that patients with MS have greater IJV flattening and a trend toward more non-IJV collaterals than healthy subjects. The role that this finding plays in the pathogenesis or progression of MS, if any, requires further study.

    View details for DOI 10.3174/ajnr.A3097

    View details for Web of Science ID 000309489800034

    View details for PubMedID 22517280

  • Transesophageal Echocardiography Guidance for Stent-Graft Repair of a Thoracic Aneurysm is Facilitated by the Ability of Partial Stent Deployment ANNALS OF VASCULAR SURGERY Crimi, E., Lee, J. T., Dake, M. D., van der Starre, P. J. 2012; 26 (6)


    Transesophageal echocardiography (TEE) is routinely used in our Institution for monitoring correct positioning of thoracic aortic stent grafts. We present a case of successful endovascular repair of three discrete thoracic aortic aneurysms with Zenith TX2 endovascular stent grafts in an 82-year-old female patient. Our focus is on the increased value of TEE guidance because of the ability of partial stent deployment and manipulation during insertion.

    View details for DOI 10.1016/j.avsg.2012.01.013

    View details for Web of Science ID 000306436700028

    View details for PubMedID 22794345

  • Chronic cerebrospinal venous insufficiency and multiple sclerosis: history and background. Techniques in vascular and interventional radiology Dake, M. D. 2012; 15 (2): 94-100


    Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system (CNS) most commonly characterized by focal areas of myelin destruction, inflammation and axonal transection. The multicentric inflammation and demyelination of the brain and spinal cord are associated with variable neurologic symptoms ranging from mild dysfunction to debilitating. Typically, these symptoms are marked by episodes of clinical worsening followed by improvement. The cause of this disease remains unclear currently, but the underlying etiology is generally considered to be immunologically based. Other factors, including genetic, environmental and infectious influences have been implicated, as well. Now recent studies have proposed that extracranial venous obstruction, termed chronic cerebrospinal venous insufficiency (CCSVI) may have a role in the pathogenesis of MS or many of its associated clinical manifestations. It is postulated that venous narrowing affecting one or more of the jugular veins and/or the azygous vein in the chest may be responsible for abnormal blood flow in the veins draining the brain and spinal cord. The abnormal flow may initiate and/or sustain a local inflammatory response at the blood-brain barrier that promote pathological changes within the CNS. This review presents the history of the relationship between the vascular system and MS and explores the background of basic and clinical investigations that led to the concept of CCSVI.

    View details for DOI 10.1053/j.tvir.2012.02.002

    View details for PubMedID 22640498

  • Endovascular correction of cerebrovenous anomalies in multiple sclerosis: A retrospective review of an uncontrolled case series VASCULAR MEDICINE Dake, M. D., Dantzker, N., Bennett, W. L., Cooke, J. P. 2012; 17 (3): 131-137


    Endovascular intervention for obstruction to venous drainage of the head and neck is an established treatment for disorders such as superior vena cava syndrome. Some patients with multiple sclerosis have been observed to have anomalies of the veins draining the head and neck. It is possible that some symptoms associated with multiple sclerosis may be secondary to disturbed venous flow. In an uncontrolled clinical series of 40 patients who had been previously diagnosed with multiple sclerosis, anomalies of the venous drainage of the head and neck were observed, including venous stenoses of the internal jugular veins. In 38 of 40 patients, venous stents were placed with restoration of luminal dimensions and abrogation of the venous pressure gradient. The angiographic and hemodynamic improvement was associated with improvement in symptomatology, most particularly in cognitive and constitutional symptoms that may be related to cerebrovenous flow. Serious complications included death in one subject and stent embolization requiring open heart surgery in another. In conclusion, in this series, endovascular intervention to correct venous stenosis associated with multiple sclerosis was associated with improvement in symptoms possibly related to disturbed venous hemodynamics. However, given the serious adverse events in this small series, a randomized clinical trial is required to confirm these findings, and to determine if the procedure has any effect on the progression of multiple sclerosis, or untoward long-term adverse effects.

    View details for DOI 10.1177/1358863X12440125

    View details for Web of Science ID 000304719900001

    View details for PubMedID 22496109

  • Incidence and outcomes after infolding or collapse of thoracic stent grafts Vascular Annual Meeting of the Society-for-Vascular-Surgery (SVS) / Plenary Session of William Von Liebig Forum / 36th Annual Spring Meeting of the Peripheral-Vascular-Surgery-Society Kasirajan, K., Dake, M. D., Lumsden, A., Bavaria, J., Makaroun, M. S. MOSBY-ELSEVIER. 2012: 652–58


    Device-related complications in the thoracic aorta are partly due to the unavoidable proximal angulation and increased flow-related forces. The present study evaluated the incidence, predictors, and outcome of the complication of infolding with the GORE TAG thoracic endoprosthesis (TAG device) to better understand the factors that might help predict these events.We reviewed all complaints reported to W. L. Gore and Associates (Flagstaff, Ariz) related to device infolding after the use of the GORE TAG device on or before December 2008. Events related to device infolding were evaluated. Reporting physicians and local company representatives were contacted, when necessary, to assemble all available imaging, data, and outcomes related to these case reports. When available, computed tomography images were reviewed to confirm aortic landing zone diameters, which were subsequently compared with the implanted device size.From 1998 through December 2008, device infolding was reported in 139 patients (mean age, 40 ± 17 years; 73.4% men) from 33,289 device implants (reported incidence, 0.4%). Events were noted in implants for trauma (60%), dissection (19%), aneurysm (10%), and other (9%) and unknown (2%) etiologies. In 77 patients with available imaging, the average minimum aortic diameter was 21.4 ± 4.4 mm. The mean device diameter was 28.5 ± 3.5 mm, with an average oversizing of nearly 33%. Of reported patients, 51% were asymptomatic, with the diagnosis being made on routine chest imaging. Time to diagnosis was 76 ± 222 days (median, 9.5 days). Only 16 patients received no intervention after the diagnosis of device infolding, all of whom were asymptomatic. The other 123 patients underwent 135 interventions. Of these, 30 patients (24%) underwent open surgical conversion and complete or partial endograft removal. The other interventions included a variety of endovascular techniques, such as large balloon-expandable stent(s) in 40%, relining with additional endograft(s) in 31%, and repeat ballooning in seven patients. Ten patients died after device infolding, all after one or more attempts to repair the infolded device: five died of symptoms related to the infolding and five secondary to the intervention undertaken to correct the device infolding.TAG device infolding appears to be an infrequent event, primarily occurring in young trauma patients secondary to excessive oversizing and severe proximal aortic angulation. However, there clearly exists a need for devices that treat such patients. As a result, future device designs should consider the compression failure mode when being designed in order to help prevent such events.

    View details for DOI 10.1016/j.jvs.2011.09.079

    View details for Web of Science ID 000300941100003

    View details for PubMedID 22169662

  • Endovascular Management of Pseudoaneurysm Formation in the Ascending Aorta Following Lung Transplantation JOURNAL OF ENDOVASCULAR THERAPY Joyce, D. L., Singh, S. K., Mallidi, H. R., Dake, M. D. 2012; 19 (1): 52-57


    To demonstrate the role of endovascular approaches to the ascending aorta in the post-transplant context.Three patients (2 women and 1 man aged 52, 68, and 43 years, respectively) developed pseudoaneurysm of the ascending aorta following thoracic organ transplantation. Due to the prohibitive risk of open surgery in each case, an endovascular repair of the ascending aorta was performed, with implantation of 1 to 3 stent-grafts to span the lesions. Follow-up imaging demonstrated complete exclusion of the pseudoaneurysms, with excellent outcomes at 4 months, 6 months, and 3 years.Stent-grafting of the ascending aorta represents a viable approach to pseudoaneurysm in the post-transplant setting.

    View details for Web of Science ID 000300076600010

    View details for PubMedID 22313202

  • 2012 ACCF/AHA/ACR/SCAI/SIR/STS/SVM/SVN/SVS Key data elements and definitions for peripheral atherosclerotic vascular disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Clinical Data Standards (Writing Committee to develop Clinical Data Standards for peripheral atherosclerotic vascular disease). Journal of the American College of Cardiology Creager, M. A., Belkin, M., Bluth, E. I., Casey, D. E., Chaturvedi, S., Dake, M. D., Fleg, J. L., Hirsch, A. T., Jaff, M. R., Kern, J. A., Malenka, D. J., Martin, E. T., Mohler, E. R., Murphy, T., Olin, J. W., Regensteiner, J. G., Rosenwasser, R. H., Sheehan, P., Stewart, K. J., Treat-Jacobson, D., Upchurch, G. R., White, C. J., Ziffer, J. A. 2012; 59 (3): 294-357

    View details for DOI 10.1016/j.jacc.2011.10.860

    View details for PubMedID 22153885

  • 2012 ACCF/AHA/ACR/SCAI/SIR/STS/SVM/SVN/SVS key data elements and definitions for peripheral atherosclerotic vascular disease: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Clinical Data Standards (Writing Committee to Develop Clinical Data Standards for Peripheral Atherosclerotic Vascular Disease). Circulation Creager, M. A., Belkin, M., Bluth, E. I., Casey, D. E., Chaturvedi, S., Dake, M. D., Fleg, J. L., Hirsch, A. T., Jaff, M. R., Kern, J. A., Malenka, D. J., Martin, E. T., Mohler, E. R., Murphy, T., Olin, J. W., Regensteiner, J. G., Rosenwasser, R. H., Sheehan, P., Stewart, K. J., Treat-Jacobson, D., Upchurch, G. R., White, C. J., Ziffer, J. A., Hendel, R. C., Bozkurt, B., Fonarow, G. C., Jacobs, J. P., Peterson, P. N., Roger, V. L., Smith, E. E., Tcheng, J. E., Wang, T., Weintraub, W. S. 2012; 125 (2): 395-467

    View details for DOI 10.1161/CIR.0b013e31823299a1

    View details for PubMedID 22144570

  • 2012 ACCF/AHA/ACR/SCAI/SIR/STS/SVM/SVN/SVS Key Data Elements and Definitions for Peripheral Atherosclerotic Vascular Disease A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Clinical Data Standards (Writing Committee to Develop Clinical Data Standards for Peripheral Atherosclerotic Vascular Disease) CIRCULATION Creager, M. A., Belkin, M., Bluth, E. I., Casey, D. E., Chaturvedi, S., Dake, M. D., Fleg, J. L., Hirsch, A. T., Jaff, M. R., Kern, J. A., Malenka, D. J., Martin, E. T., Mohler, E. R., Murphy, T., Olin, J. W., Regensteiner, J. G., Rosenwasser, R. H., Sheehan, P., Stewart, K. J., Treat-Jacobson, D., Upchurch, G. R., White, C. J., Ziffer, J. A. 2012; 125 (2): 395-467
  • Nitinol Stents With Polymer-Free Paclitaxel Coating for Lesions in the Superficial Femoral and Popliteal Arteries Above the Knee: Twelve-Month Safety and Effectiveness Results From the Zilver PTX Single-Arm Clinical Study JOURNAL OF ENDOVASCULAR THERAPY Dake, M. D., Scheinert, D., Tepe, G., Tessarek, J., Fanelli, F., Bosiers, M., Ruhlmann, C., Kavteladze, Z., Lottes, A. E., Ragheb, A. O., Zeller, T. 2011; 18 (5): 613-623


    To report a prospective, single-arm, multicenter clinical study evaluating the Zilver PTX drug-eluting stent for treating the above-the-knee femoropopliteal segment (NCT01094678; ).The Zilver PTX drug-eluting stent is a self-expanding nitinol stent with a polymer-free paclitaxel coating. Patients with symptomatic (Rutherford category 2-6) de novo or restenotic lesions (including in-stent stenosis) of the above-the-knee femoropopliteal segment were eligible for enrollment. Between April 2006 and June 2008, 787 patients (578 men; mean age 66.6±9.5 years) were enrolled at 30 international sites.Nine hundred lesions (24.3% restenotic lesions of which 59.4% were in-stent stenoses) were treated with 1722 Zilver PTX stents; the mean lesion length was 99.5±82.1 mm. The 12-month Kaplan-Meier estimates included an 89.0% event-free survival rate, an 86.2% primary patency rate, and a 90.5% rate of freedom from target lesion revascularization. There were no paclitaxel-related adverse events reported. The 12-month stent fracture rate was 1.5%. The ankle-brachial index, Rutherford score, and walking distance/speed scores significantly improved (p<0.001) from baseline to 12 months.These results indicate that the Zilver PTX drug-eluting stent is safe for treatment of patients with de novo and restenotic lesions of the above-the-knee femoropopliteal segment. At 1 year, the overall anatomical and clinical effectiveness results suggest that this stent is a promising endovascular therapy.

    View details for Web of Science ID 000295964400001

    View details for PubMedID 21992630

  • Chronic cerebrospinal venous insufficiency in multiple sclerosis: a historical perspective FUNCTIONAL NEUROLOGY Dake, M. D., Zivadinov, R., Haacke, E. M. 2011; 26 (4): 181-195


    Chronic cerebrospinal venous insufficiency (CCSVI) is a term used to describe impaired venous drainage from the central nervous system (CNS) caused by abnormalities in anatomy and flow affecting the extracranial veins. Recently, it has been proposed that CCSVI may contribute to the pathogenesis of multiple sclerosis (MS). It is hypothesized that venous obstruction results in abnormal flow that promotes inflammation at the blood-brain barrier and that this triggers a process marked by a disturbance of homeostasis within the CNS that leads to demyelination and neurodegeneration. The venous abnormalities of CCSVI are often diagnosed by ultrasound or magnetic resonance venography, however the prevalence of CCSVI detailed in groups of MS patients and patients without MS varies widely in published reports. Increased standardization of diagnostic studies to evaluate both anatomical and physiological findings associated with CCSVI is needed. The purpose of this article is to provide a background to understand the development of the theory of CCSVI and to frame the relevant issues regarding its diagnosis and relationship to the pathogenesis of MS.

    View details for Web of Science ID 000301822200003

    View details for PubMedID 22364939

  • Paclitaxel-Eluting Stents Show Superiority to Balloon Angioplasty and Bare Metal Stents in Femoropopliteal Disease Twelve-Month Zilver PTX Randomized Study Results CIRCULATION-CARDIOVASCULAR INTERVENTIONS Dake, M. D., Ansel, G. M., Jaff, M. R., Ohki, T., Saxon, R. R., Smouse, H. B., Zeller, T., Roubin, G. S., Burket, M. W., Khatib, Y., Snyder, S. A., Ragheb, A. O., White, J. K., Machan, L. S. 2011; 4 (5): 495-504


    Sustained benefits of drug-eluting stents in femoropopliteal arteries have not been demonstrated. This prospective, multinational, randomized study was designed to compare the 12-month safety and effectiveness of a polymer-free, paclitaxel-coated nitinol drug-eluting stent (DES) with percutaneous transluminal angioplasty (PTA) and provisional bare metal stent (BMS) placement in patients with femoropopliteal peripheral artery disease.Patients were randomly assigned to primary DES implantation (n=236) or PTA (n=238). Demographics and lesion characteristics were similar between groups (eg, average lesion length, approximately 65±40 mm). One hundred twenty patients had acute PTA failure and underwent secondary random assignment to provisional DES (n=61) or BMS (n=59). Primary end points were the 12-month rates of event-free survival and patency in the primary DES and PTA groups. Compared with the PTA group, the primary DES group exhibited superior 12-month event-free survival (90.4% versus 82.6%; P=0.004) and primary patency (83.1% versus 32.8%; P<0.001), satisfying the primary hypotheses. In the secondary evaluations, (1) the primary DES group exhibited superior clinical benefit compared with the PTA group (88.3% versus 75.8%; P<0.001), (2) the provisional DES group exhibited superior primary patency (89.9% versus 73.0%; P=0.01) and superior clinical benefit (90.5% and 72.3%, P=0.009) compared with the provisional BMS group, and (3) the stent fracture rate (both DES and BMS) was 0.9% (4/457).Femoropopliteal peripheral artery disease treatment with the paclitaxel-eluting stent was associated with superior 12-month outcomes compared with PTA and provisional BMS placement.

    View details for DOI 10.1161/CIRCINTERVENTIONS.111.962324

    View details for Web of Science ID 000300549100017

    View details for PubMedID 21953370

  • Comparison of MR and Contrast Venography of the Cervical Venous System in Multiple Sclerosis AMERICAN JOURNAL OF NEURORADIOLOGY Zaharchuk, G., Fischbein, N. J., Rosenberg, J., Herfkens, R. J., Dake, M. D. 2011; 32 (8): 1482-1489


    MRV has been proposed as a possible screening method to identify chronic cerebrospinal venous insufficiency, which may play a role in MS. We report our initial experience comparing MRV and CV in MS patients to evaluate venous stenosis and collateral venous drainage.Time-of-flight and time-resolved imaging of contrast kinetics MRV and CV were performed in 39 MS patients. The presence and severity of both IJ vein caliber changes and non-IJ collaterals were graded by using a 4-point scale by 2 radiologists in an independent and blinded manner.Both studies frequently showed venous abnormalities, most commonly IJ flattening at the C1 level and in the lower neck. There was moderate-to-good agreement between the modalities (κ = 0.55; 95% CI, 0.45%-0.65%). For collaterals, agreement was only fair (κ = 0.30; 95% CI, 0.09%-0.50%). The prevalence of IJ segments graded mild or worse on CV was 54%. If CV was considered a standard, the sensitivity and specificity of MRV was 0.79 (0.71-0.86) and 0.76 (0.67-0.83), respectively. Degree of stenosis was related to the severity of collaterals for CV but not for MRV.IJ caliber changes were seen in characteristic locations on both MRV and CV in MS patients. Agreement between modalities was higher for stenosis than for collaterals. If CV is considered a standard, MRV performance is good but may require additional improvement before MRV can be used for screening.

    View details for DOI 10.3174/ajnr.A2549

    View details for Web of Science ID 000295706200021

    View details for PubMedID 21757521

  • Polymer-free Paclitaxel-coated Zilver PTX Stents-Evaluation of Pharmacokinetics and Comparative Safety in Porcine Arteries JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Dake, M. D., Van Alstine, W. G., Zhou, Q., Ragheb, A. O. 2011; 22 (5): 603-610


    To evaluate the pharmacokinetics and safety of the Zilver PTX Drug-Eluting Stent (Cook Medical, Bloomington, Indiana) in a normal porcine artery model.Pharmacokinetic analyses were performed using 18 pigs, each implanted with four paclitaxel-coated stents. Paclitaxel remaining on the stents, delivered locally (to artery wall), regionally (to adjacent and downstream muscle), and systemically (to plasma), was determined at various times through 56 days. For safety evaluation, local, regional, and systemic responses were grossly and histologically assessed at 1 month, 3 months, and 6 months in 21 additional pigs and compared with the responses to bare metal stents in 21 separate pigs.Stents delivered approximately 95% of the total paclitaxel within 24 hours after deployment. Nonetheless, there were sustained paclitaxel levels in the artery wall through 56 days, maintained at approximately 20% of the peak level through 14 days. Very little paclitaxel was distributed regionally or systemically, becoming undetectable in plasma at 10 hours. Complete necropsy, hematology, and serum chemistry revealed no adverse effects associated with the paclitaxel-coated stents. Within 3 months, vessels with both paclitaxel-coated and bare metal stents showed comparable, complete healing.The Zilver PTX stent appears to be safe, achieves sustained paclitaxel levels in the artery wall, and shows complete vessel healing comparable to bare metal stents within 3 months.

    View details for DOI 10.1016/j.jvir.2010.12.027

    View details for Web of Science ID 000290358700003

    View details for PubMedID 21419649

  • Development of a Research Agenda for Evaluation of Interventional Therapies for Chronic Cerebrospinal Venous Insufficiency: Proceedings from a Multidisciplinary Research Consensus Panel JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Siskin, G. P., Haskal, Z. J., McLennan, G., Dake, M. D., Haacke, E. M., McDonald, S., Royal, W., Vedantham, S., Hubbard, D., Sclafani, S. J., Andrews, R. T., Sauder, H. 2011; 22 (5): 587-593

    View details for DOI 10.1016/j.jvir.2011.03.007

    View details for Web of Science ID 000290358700001

    View details for PubMedID 21514515

  • Report on endograft management of traumatic thoracic aortic transections at 30 days and 1 year from a multidisciplinary subcommittee of the Society for Vascular Surgery Outcomes Committee JOURNAL OF VASCULAR SURGERY Dake, M. D., White, R. A., Diethrich, E. B., Greenberg, R. K., Criado, F. J., Bavaria, J. E., Piccolo, R. S., Siami, F. S. 2011; 53 (4): 1091-1096


    The Society for Vascular Surgery Outcomes Committee, including ad hoc members from Society of Thoracic Surgeons, American Association of Thoracic Surgery, and Society for Interventional Radiology, collected outcomes of patients with traumatic thoracic aortic transections treated with endovascular grafts. Results through 1 year of follow-up are reported.Data from five physician-sponsored investigational device exemption clinical trials from 2000 to 2008 were entered using standardized forms and definitions. Adverse events were reported early (≤30 days) and late (>30 days) by body system. Major adverse events included one or more of the following: death, stroke, myocardial infarction, renal failure, respiratory failure, paralysis, or bowel ischemia.There were 60 symptomatic patients (68.3% men; mean age, 46 years) with traumatic aortic transections, of which 97% were due to a motor vehicle accident and 3% were related to other blunt trauma. The average total injury severity score was 39, most with involvement of the chest and abdomen. The average surgical time was 125 minutes. The mean hospital length of stay was 17 days. Associated procedures for the management of nonaortic injuries occurred in 51.7%. All-cause mortality was 9.1% at 30 days and 14.4% at 1 year. One or more major adverse events occurred in 23.3% of the patients, major adverse events occurred early in 20.0% and late in 3.6%. Death accounted for 41.7% of the early and all of the late major adverse events. Early adverse events included 16.7% pulmonary, 13.3% neurologic, and 11.7% vascular complications. Late adverse events included one patient (1.8%) with pulmonary failure and one patient (1.8%) who died of an unknown cause.One-year results of endograft placement for the management of patients with traumatic aortic injury are acceptable. Most cases treated were due to motor vehicle accident and associated with multiple coexisting injuries. Approximately three-quarters of the deaths occurred ≤30 days, indicating the acute severity of the condition. Although the relatively low rates of adverse and major adverse events are consistent with what is anticipated in an otherwise healthy population, future device and procedural developments may facilitate improved outcomes in the future.

    View details for DOI 10.1016/j.jvs.2010.11.126

    View details for Web of Science ID 000289012600029

    View details for PubMedID 21439459

  • Report on the results of thoracic endovascular aortic repair for acute, complicated, type B aortic dissection at 30 days and 1 year from a multidisciplinary subcommittee of the Society for Vascular Surgery Outcomes Committee JOURNAL OF VASCULAR SURGERY White, R. A., Miller, D. C., Criado, F. J., Dake, M. D., Diethrich, E. B., Greenberg, R. K., Piccolo, R. S., Siami, F. S. 2011; 53 (4): 1082-1090


    This study analyzed 1-year outcome after thoracic endovascular aortic repair (TEVAR) in patients with complicated type B aortic dissection (cTBAoD) who had rupture or malperfusion and symptom onset ≤14 days (acute), 15 to 30 days (subacute), and 31 to 90 days (chronic) until required intervention. The main focus of this report is primarily on the acute cohort.Clinical data were systematically collected from five physician-sponsored investigational device exemption (IDE) clinical trials between 2000 and 2008 using standardized definitions and forms. Adverse events were reported early (≤30 days) and late (>30 days) by body system. Major adverse events included death, stroke, myocardial infarction, renal failure, respiratory failure, paralysis, and bowel ischemia.There were 99 cTBAoD patients: 85 were acute, 11 were subacute, and 3 were chronic. Among the acute patients, 31.8% had rupture and 71.8% had malperfusion, including 55.7% lower extremity, 36.1% renal, 19.7% visceral, 8.2% other, and 3.3% spinal cord (patients may have more than one source). Rupture and malperfusion were both reported for three acute patients. Additional findings for the acute cohort included pain (76.5%), hypertension (43.5%), and bleeding (8.2%); comorbidities included hypertension (83.5%), current/past smoking history (69.8%), and diabetes (12.9%). The main focus of this analysis was the acute cohort (n = 85). Age averaged 59 years (72.9% male). Early adverse events included pulmonary (36.5%), vascular (28.2%), renal (25.9%), and neurologic (23.5%). Early major adverse events occurred in 37.6% of patients, including death (10.6%), stroke (9.4%), renal failure (9.4%), and paralysis (9.4%); late adverse events included vascular (15.8%), cardiac (10.5%), gastrointestinal (6.6%), and hemorrhage (5.3%). The point-estimate mortality rate was 10.8 (95% confidence interval [CI], 4.1-17.5) at 30 days and 29.4 (95% CI, 18.4-40.4) at 1 year, when 34 patients remained at risk.Emergency TEVAR for patients with cTBAoD (malperfusion or rupture) provided acceptable mortality and morbidity results out to 1 year. Manufacturers can use this 30-day mortality point-estimate of 10.8 (95% CI, 4.1-17.5) for the acute cohort to establish a performance goal for use in single-arm commercial IDE trials if the Food and Drug Administration and other regulatory bodies concur.

    View details for DOI 10.1016/j.jvs.2010.11.124

    View details for Web of Science ID 000289012600028

    View details for PubMedID 21334174

  • Magnetic Resonance Imaging of Carotid Atherosclerotic Plaque in Clinically Suspected Acute Transient Ischemic Attack and Acute Ischemic Stroke CIRCULATION Parmar, J. P., Rogers, W. J., Mugler, J. P., Baskurt, E., Altes, T. A., Nandalur, K. R., Stukenborg, G. J., Phillips, C. D., Hagspiel, K. D., Matsumoto, A. H., Dake, M. D., Kramer, C. M. 2010; 122 (20): 2031-2038


    Carotid atherosclerotic plaque rupture is thought to cause transient ischemic attack (TIA) and ischemic stroke (IS). Pathological hallmarks of these plaques have been identified through observational studies. Although generally accepted, the relationship between cerebral thromboembolism and in situ atherosclerotic plaque morphology has never been directly observed noninvasively in the acute setting.Consecutive acutely symptomatic patients referred for stroke protocol magnetic resonance imaging/angiography underwent additional T1- and T2-weighted carotid bifurcation imaging with the use of a 3-dimensional technique with blood signal suppression. Two blinded reviewers performed plaque gradings according to the American Heart Association classification system. Discharge outcomes and brain magnetic resonance imaging results were obtained. Image quality for plaque characterization was adequate in 86 of 106 patients (81%). Eight TIA/IS patients with noncarotid pathogenesis were excluded, yielding 78 study patients (38 men and 40 women with a mean age of 64.3 years, SD 14.7) with 156 paired watershed vessel/cerebral hemisphere observations. Thirty-seven patients had 40 TIA/IS events. There was a significant association between type VI plaque (demonstrating cap rupture, hemorrhage, and/or thrombosis) and ipsilateral TIA/IS (P<0.001). A multiple logistic regression model including standard Framingham risk factors and type VI plaque was constructed. Type VI plaque was the dominant outcome-associated observation achieving significance (P<0.0001; odds ratio, 11.66; 95% confidence interval, 5.31 to 25.60).In situ type VI carotid bifurcation region plaque identified by magnetic resonance imaging is associated with ipsilateral acute TIA/IS as an independent identifier of events, thereby supporting the dominant disease pathophysiology.

    View details for DOI 10.1161/CIRCULATIONAHA.109.866053

    View details for Web of Science ID 000284213200013

    View details for PubMedID 21041694

  • Percutaneous Occlusion of the Left Subclavian and Celiac Arteries before or during Endograft Repair of Thoracic and Thoracoabdominal Aortic Aneurysms with Detachable Nitinol Vascular Plugs JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Tholpady, A., Hendricks, D. E., Bozlar, U., Turba, U. C., Sabri, S. S., Angle, J. F., Lan, B. A., Cherry, K. J., Dake, M. D., Matsumoto, A. H., Saad, W. E., Park, A. W., Bonatti, H., Hagspiel, K. D. 2010; 21 (10): 1501-1507


    To review an experience with the Amplatzer vascular plug (AVP) for prevention of type II endoleaks during endovascular aneurysm repair (EVAR) of thoracic and thoracoabdominal aneurysms.Retrospective review was undertaken of 14 patients undergoing transcatheter occlusion of the left subclavian (n = 12) or celiac artery (n = 2) with the AVP as part of EVAR of thoracic and thoracoabdominal aneurysms at a single institution. Procedural criteria evaluated were success at target vessel occlusion, the number of AVPs used, use of adjunctive embolization devices, and embolization-related ischemic end-organ events. Follow-up imaging criteria included evaluation of persistent target vessel occlusion, evidence of device migration, and the presence and characterization of endoleak secondary to AVP failure.Complete target vessel occlusion was documented for all cases. In six cases, more than one AVP was placed, with an average of 1.5 devices per patient. In two cases, adjunctive coils were placed. Computed tomographic or magnetic resonance angiography follow-up was available for all patients (mean follow-up, 419 days; range 28-930 d). No case showed evidence of device migration or type II endoleak resulting from AVP failure. There was a single instance of left subclavian artery recanalization without type II endoleak. There were no embolization-related ischemic end-organ events.Transcatheter arterial occlusion of the subclavian and celiac arteries with the AVP is a valuable adjunct to endografting in cases in which side branch embolization is necessary to extend the landing zone.

    View details for DOI 10.1016/j.jvir.2010.05.021

    View details for Web of Science ID 000282912000006

    View details for PubMedID 20801685

  • Incomplete Endograft Apposition to the Aortic Arch: Bird-Beak Configuration Increases Risk of Endoleak Formation after Thoracic Endovascular Aortic Repair RADIOLOGY Ueda, T., Fleischmann, D., Dake, M. D., Rubin, G. D., Sze, D. Y. 2010; 255 (2): 645-652


    To determine the clinical importance of the bird-beak configuration after thoracic endovascular aortic repair (TEVAR).The institutional review board approved this retrospective study and waived the requirement to obtain informed consent from patients. Sixty-four patients (40 men, 24 women; mean age, 64 years) who underwent TEVAR were evaluated. The treated diseases included dissection (n = 29), degenerative aneurysm (n = 13), acute traumatic transection (n = 8), pseudoaneurysm (n = 4), penetrating aortic ulcer (n = 6), intramural hematoma (n = 2), and mycotic aneurysm (n = 2). Bird-beak configuration, defined as the incomplete apposition of the proximal endograft with a wedge-shaped gap between the device and the aortic wall, was assessed with postprocedural CT angiography. The presence and length of the bird-beak configuration were compared with the formation of endoleaks and adverse clinical events.Endoleaks were detected in 26 (40%) of the 64 patients, including 14 with type Ia endoleak formation, one with type Ib endoleak formation, six with type II endoleak formation (from the left subclavian artery), two with type IIo endoleak formation (from other arteries), and three with type III endoleak formation. Bird-beak configuration was observed in 28 (44%) of 64 patients and correlated significantly with the risk of developing a type Ia or IIa endoleak (P < .01). Mean bird-beak length was significantly longer (P < .01) in patients with a type Ia or II endoleak (mean length, 14.3 and 13.9 mm, respectively) than in patients without endoleaks (mean length, 8.4 mm). Adverse events included early aortic-related death in three patients, additional treatment for endoleak in eight patients, and stent-graft collapse or infolding in six patients.Detection of bird-beak configuration is helpful in the prediction of adverse clinical events after TEVAR.

    View details for DOI 10.1148/radiol.10091468

    View details for Web of Science ID 000276976200040

    View details for PubMedID 20413775

  • Endovascular treatment of aortic pseudoaneurysm in Behcet disease JOURNAL OF VASCULAR SURGERY Liu, C., Ye, W., Liu, B., Zeng, R., Wu, W., Dake, M. D. 2009; 50 (5): 1025-1030


    This study evaluated the feasibility, efficacy, and outcome of endovascular therapy combined with immunosuppressive therapy for aortic pseudoaneurysms in patients with Behçet disease.Between April 2002 and April 2008, 12 pseudoaneurysms (9 involving the intrarenal abdominal aorta, 1 at the suprarenal level, and 2 in the supraceliac aorta) in nine men and one woman with Behçet disease were evaluated at Peking Union Medical Center (PUMC). Three bifurcated stent grafts and seven tubular stent grafts, including two fenestrated stent grafts, were deployed. All 10 patients received immunosuppressive therapy after the implant procedure.All patients underwent successful endovascular therapy without major complications during the 30 days immediately after the procedure. One patient with two aneurysms had treatment of only the larger infrarenal symptomatic aneurysm, but the smaller suprarenal pseudoaneurysm was not addressed because of its proximity to mesenteric branches. During a mean follow-up of 25.8 months (range, 6-50 months), nine aneurysms resolved completely in eight patients. The only untreated aneurysm, which coexisted with a treated lesion, remained stable under imaging observation. Three aneurysms recurred in two patients. At 6 months, one patient presented with a new aneurysm at the femoral artery access site for stent graft introduction and another formed at the proximal margin of the stent graft. Despite medical advice, he had stopped immunotherapy. He died from aneurysm rupture 8 months after stent deployment. Another patient with recurrent aneurysmal disease at the distal margin of the primary stent was successfully treated with an additional stent graft. These two were the only patients who did not adhere to taking immunosuppressant medicine after discharge.Endovascular stent graft placement combined with immunosuppressive treatment for aortic pseudoaneurysms in Behçet disease is a feasible and effective management option. Long-term immunosuppressive therapy after endovascular repair is important to limit pseudoaneurysm recurrence.

    View details for DOI 10.1016/j.jvs.2009.06.009

    View details for Web of Science ID 000271390300009

    View details for PubMedID 19660895

  • Management strategies for thoracic stent-graft repair of distal aortic arch lesions: is intentional subclavian artery occlusion a safe procedure? EUROPEAN RADIOLOGY Fanelli, F., Dake, M. D., Salvatori, F. M., Pucci, A., Mazzesi, G., Lucatelli, P., Rossi, P., Passariello, R. 2009; 19 (10): 2407-2415


    The aim of this retrospective analysis was to assess the clinical consequences after intentional left subclavian artery (LSA) occlusion. Thirty-seven patients, 27 type B dissection and 10 thoracic aneurysm, with short proximal neck (less than 2 cm) underwent endovascular treatment with intentional exclusion of LSA origin. No immediate complications occurred. Mean arterial pressure gradient, between right and left arms, ranged from 15 to 45 mmHg. After a mean follow-up of 43.70 + or - 24.01 months, mild left arm symptoms secondary to flow reduction occurred in eight cases (21.6%) but only one required LSA transposition, after 8 months, for visual impairment. Type II endoleaks from excluded LSA occurred in 10 cases (27.0%): in seven patients, leaks were treated with coils and/or glue embolization; in one case, leak sealed spontaneously; one patient died before leak embolization could occur; one patient refused any further treatment. Intentional exclusion of the LSA may be justified when a longer proximal landing zone in the aortic arch is required.

    View details for DOI 10.1007/s00330-009-1433-3

    View details for Web of Science ID 000270268700013

    View details for PubMedID 19430794

  • TEVAR for Acute Uncomplicated Aortic Dissection: Immediate Repair Versus Medical Therapy SEMINARS IN VASCULAR SURGERY Tang, D. G., Dake, M. D. 2009; 22 (3): 145-151


    Medical management remains the standard treatment modality for acute uncomplicated descending aortic dissections. Intervention (by either open surgery or an endovascular approach) is currently reserved for patients who present with or subsequently develop complications (ie, complicated dissections). Despite the success of medical therapy in the acute management of uncomplicated dissection, long-term morbidity and mortality are far from ideal. The introduction of thoracic endovascular aortic repair (TEVAR) has been associated with reductions in morbidity and mortality in the treatment of complicated dissections. There is limited data regarding TEVAR for acute uncomplicated dissections. Early results from the INSTEAD (Investigation of Stent Grafts in Patients with Type B Aortic Dissection) trial, a randomized trial for TEVAR in subacute/chronic uncomplicated dissections, were not favorable. The ADSORB (Acute Uncomplicated Aortic Dissection Type B: Evaluating Stent-Graft Placement or Best Medical Treatment Alone) trial, a randomized trial for TEVAR in acute dissections, is currently underway. Nonetheless, current data available, including multiple reports proposing a variety of predictive factors, suggest that there may be a subset of higher-risk patients with acute uncomplicated dissections who could benefit from TEVAR.

    View details for DOI 10.1053/j.semvascsurg.2009.07.005

    View details for Web of Science ID 000270504700005

    View details for PubMedID 19765524

  • Standard of Practice for the Endovascular Treatment of Thoracic Aortic Aneurysms and Type B Dissections CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Fanelli, F., Dake, M. D. 2009; 32 (5): 849-860


    Thoracic endovascular aortic repair (TEVAR) represents a minimally invasive technique alternative to conventional open surgical reconstruction for the treatment of thoracic aortic pathologies. Rapid advances in endovascular technology and procedural breakthroughs have contributed to a dramatic transformation of the entire field of thoracic aortic surgery. TEVAR procedures can be challenging and, at times, extraordinarily difficult. They require seasoned endovascular experience and refined skills. Of all endovascular procedures, meticulous assessment of anatomy and preoperative procedure planning are absolutely paramount to produce optimal outcomes. These guidelines are intended for use in quality-improvement programs that assess the standard of care expected from all physicians who perform TEVAR procedures.

    View details for DOI 10.1007/s00270-009-9668-6

    View details for Web of Science ID 000269838400001

    View details for PubMedID 19688371

  • Infolding and collapse of thoracic endoprostheses: Manifestations and treatment options JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sze, D. Y., Mitchell, R. S., Miller, D. C., Fleischmann, D., Frisoli, J. K., Kee, S. T., Verma, A., Sheehan, M. P., Dake, M. D. 2009; 138 (2): 324-333


    We sought to review the clinical sequelae and imaging manifestations of thoracic aortic endograft collapses and infoldings and to evaluate minimally invasive methods of repairing such collapses.Two hundred twenty-one Gore endografts (Excluder, TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz) were deployed in 145 patients for treatment of pathologies including aneurysms and pseudoaneurysms, dissections, penetrating ulcers, transections, fistulae, mycotic aneurysms, and neoplastic invasions in 6 different prospective trials at a single institution from 1997 to 2007. Device collapses and infoldings were analyzed retrospectively, including review of anatomic parameters, pathologies treated, device sizing and selection, clinical sequelae, methods of repair, and outcome.Six device collapses and infoldings were identified. Oversized devices placed into small-diameter aortas and imperfect proximal apposition to the lesser curvature were seen in all proximal collapses, affecting patients with transections and pseudoaneurysms. Infoldings in patients undergoing dissection represented incomplete initial expansion rather than delayed collapse. Delayed collapse occurred as many as 6 years after initial successful deployment, apparently as a result of changes in the aortic configuration from aneurysmal shrinkage. Clinical manifestations ranged from life-threatening ischemia to complete lack of symptoms. Collapses requiring therapy were remedied percutaneously by bare stenting or in one case by branch vessel embolization.Use of oversized devices in small aortas carries a risk of device failure by collapse, which can occur immediately or after years of delay. When clinically indicated, percutaneous repair can be effectively performed.

    View details for DOI 10.1016/j.jtcvs.2008.12.007

    View details for Web of Science ID 000268157800011

    View details for PubMedID 19619775

  • Factors Portending Endoleak Formation After Thoracic Aortic Stent-Graft Repair of Complicated Aortic Dissection CIRCULATION-CARDIOVASCULAR INTERVENTIONS Sze, D. Y., Van den Bosch, M. A., Dake, M. D., Miller, D. C., Hofmann, L. V., Varghese, R., Malaisrie, S. C., van der Starre, P. J., Rosenberg, J., Mitchell, R. S. 2009; 2 (2): 105-112


    Endoleaks after stent-graft repair of aortic dissections are poorly understood but seem substantially different from those seen after aneurysm repair. We studied anatomic and clinical factors associated with endoleaks in patients who underwent stent-graft repair of complicated type B aortic dissections.From 2000 to 2007, 37 patients underwent stent-graft repair of acute (< or =14 days; n=23), subacute (15 to 90 days; n=10) or chronic (>90 days; n=4) complicated type B aortic dissections using the Gore Thoracic Excluder (n=17) or TAG stent-grafts (n=20) under an investigator-sponsored protocol. Endoleaks were classified as imperfect proximal seal, flow through fenestrations or branches, or complex (both). Variables studied included coverage of the left subclavian artery, aortic curvature, completeness of proximal apposition, dissection chronicity, and device used. Endoleaks were found during follow-up (mean, 22 months) in 59% of patients, and they were associated with coverage of the left subclavian artery (complex, P<0.001), small radius of curvature (type 1 and complex, P=0.05), and greatest length of unapposed proximal stent graft (complex, P<0.0001). During follow-up, 10 endoleaks resolved spontaneously, 6 required reintervention for false lumen dilatation, and 2 were stable without clinical consequences.Endoleaks are common after stent-graft repair of aortic dissection and may lead to false lumen enlargement necessitating reintervention. Anatomic complexities such as acute aortic curvature and covered side branches were associated with endoleaks, illustrating the need for dissection-specific device development.

    View details for DOI 10.1161/CIRCINTERVENTIONS.108.819722

    View details for Web of Science ID 000276051600005

    View details for PubMedID 20031703

  • Predictors of Survival Following Open and Endovascular Repair of Abdominal Aortic Aneurysms ANNALS OF VASCULAR SURGERY Matsumura, J. S., Katzen, B. T., Sullivan, T. M., Dake, M. D., Naftel, D. C. 2009; 23 (2): 153-158


    Clinical decision making for asymptomatic abdominal aortic aneurysms (AAAs) weighs risk of aneurysm rupture, treatment hazards, and overall survival expectations. AAA diameter is the primary parameter in assessing rupture risk. Perioperative risk assessment has been extensively studied, and in-hospital mortality has been reduced to less than 8% with higher-risk open repair and less than 3% with endovascular repair. The purpose of this report is to determine risk factors that predict 2-year survival following open and endovascular AAA repair. We studied 334 patients enrolled in a multicenter clinical trial evaluating an endovascular graft in comparison to standard open repair of infrarenal AAA. Demographic, medical history, physical examination, laboratory, anatomic, procedural, and standardized risk score system variables were analyzed in a multivariable Cox proportional hazard model. Overall survival was 89% at 2 years. Heart disease, cancer, and stroke were the most common causes of death, and no deaths were due to AAA rupture. Cox modeling demonstrated that there were several independent predictors for death after AAA repair: smaller body mass index (p=0.005), Society for Vascular Surgery pulmonary risk score >or=1 (p=0.005), history of erectile dysfunction (p=0.008), history of heart valve replacement (p=0.008), lower preoperative platelet count (p=0.012), larger ratio of AAA diameter/proximal neck diameter (p=0.020), and lower ankle-brachial index (p=0.031). Age, gender, and open or endovascular treatment group are not significant independent risk factors for 2-year mortality in this study. Clinical, laboratory, and anatomic factors predict survival after open and endovascular repair of AAAs. With progressive reduction of in-hospital mortality, assessment of patient longevity after AAA repair has become a more important factor in clinical decision making. Use of valid predictors of patient survival will optimize resource utilization and improve overall patient outcomes. Better selection of patients for any method of repair may improve overall utility more than choice of open or endovascular techniques.

    View details for DOI 10.1016/j.avsg.2008.07.006

    View details for Web of Science ID 000264403400001

    View details for PubMedID 18774682

  • Endovascular repair of the thoracic aorta in the post-FDA approval era JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Adams, J. D., Angle, J. F., Matsumoto, A. H., Peeler, B. B., Arslan, B., Cherry, K. J., Kern, J. A., Dake, M. D. 2009; 137 (1): 117-123


    Endovascular repair of thoracic aortic disease is rapidly progressing as an alternative to open surgical therapy. In March of 2005, the Gore TAG thoracic endoprosthesis (W. L. Gore & Associates, Inc, Flagstaff, Ariz) received Food and Drug Administration (FDA) approval for the treatment of descending thoracic aortic aneurysms. Subsequently, off-label use of the technology expanded to include additional thoracic aortic diseases. The purpose of this study was to examine whether the outcomes with this device changed after the inclusion and exclusion criteria of FDA-controlled trials no longer governed patient selection.A retrospective analysis was performed on all patients who underwent endovascular repair of the thoracic aorta with the Gore TAG device at our institution between March 23, 2005, and September 8, 2006.Fifty consecutive patients with a broad range of aortic pathologic conditions were included in the study. The results in this group compared with those of the phase II trial included the following: length of stay, 7.5 versus 7.6 days (P = .97); intensive care unit stay, 3.7 versus 2.6 days (P = .61); 30-day mortality, 2.0% versus 1.5% (P = .68); spinal cord injury, 2% versus 3% (P = .89); stroke, 4% versus 4% (P = .67); early endoleaks, 26% versus 4% (P < .01); and late endoleaks, 18% versus 7% (P = .08). At 1 year, overall survival was 92% compared with 82% in the phase II trial.In the post-FDA approval era, endovascular stent-graft therapy is frequently applied to patients with more challenging thoracic aortic anatomy and a wide range of pathologic conditions. Our results in this group are similar to outcomes reported for patients with descending thoracic aortic aneurysm exclusively.

    View details for DOI 10.1016/j.jtcvs.2008.08.004

    View details for Web of Science ID 000262611100020

    View details for PubMedID 19154913

  • Current Endograft Therapy of Type B Aortic Dissection 8th Annual International Symposium on Advances in Understanding Aortic Diseases/15th Annual Meeting of the Japanese-Society-for-Aortic-Surgery Kahn, S. L., Dake, M. D. SPRINGER-VERLAG TOKYO. 2009: 67–78
  • Atherosclerotic Peripheral Vascular Disease Symposium II Lower-Extremity Revascularization: State of the Art CIRCULATION Gray, B. H., Conte, M. S., Dake, M. D., Jaff, M. R., Kandarpa, K., Ramee, S. R., Rundback, J., Waksman, R. 2008; 118 (25): 2864-2872
  • Complicated acute type B aortic dissection: Midterm results of emergency endovascular stent-grafting 31st Annual Meeting of the Western-Thoracic-Surgical-Association Verhoye, J. P., Miller, D. C., Sze, D., Dake, M. D., Mitchell, R. S. MOSBY-ELSEVIER. 2008: 424–30


    This study assessed midterm results of emergency endovascular stent-grafting for patients with life-threatening complications of acute type B aortic dissection.Between November 1996 and June 2004, 16 patients with complicated acute type B aortic dissections (mean age 57 years, range 16-88 years) underwent endovascular stent-grafting within 48 hours of presentation. Complications included contained rupture, hemothorax, refractory chest pain, and severe visceral or lower limb ischemia. Stent-graft types included custom-made first-generation endografts and second-generation commercial stent-grafts (Gore Excluder or TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz.). Follow-up was 100% complete, averaged 36 +/- 36 months, and included postprocedural surveillance computed tomographic scans.Early mortality was 25% +/- 11% (70% confidence limit), with no late deaths. No new neurologic complications occurred. According to the latest scan, 4 patients (25%) had complete thrombosis of the false lumen; the lumen was partially thrombosed in 6 patients (38%). Distal aortic diameter was increased in only 1 patient. Actuarial survival at 1 and 5 years was 73% +/- 11%; freedom from treatment failure (including aortic rupture, device fault, reintervention, aortic death, or sudden, unexplained late death) was 67% +/- 14% at 5 years.With follow-up to 9 years, endovascular stent-grafting for patients with complicated acute type B aortic dissection conferred benefit. Consideration of emergency stent-grafting may improve the dismal outlook for these patients; future refinements in stent-graft design and technology and earlier diagnosis and intervention should be associated with improved results.

    View details for DOI 10.1016/j.jtcvs.2008.01.046

    View details for Web of Science ID 000258535300026

    View details for PubMedID 18692652

  • Randomized, multicenter study comparing expanded polytetrafluoroethylene-covered endoprosthesis placement with percutaneous transluminal angioplasty in the treatment of superficial femoral artery occlusive disease JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Saxon, R. R., Dake, M. D., Volgelzang, R. L., Katzen, B. T., Becker, G. J. 2008; 19 (6): 823-832


    To compare the safety and effectiveness of the Viabahn endoprosthesis with that of percutaneous transluminal angioplasty (PTA) alone in the treatment of symptomatic peripheral arterial disease (PAD) affecting the superficial femoral artery (SFA).From 1998 to 1999, patients with symptomatic SFA PAD were enrolled in a prospective, multicenter randomized study and underwent either PTA alone (n = 100) or PTA followed by stent-graft placement (expanded polytetrafluoroethylene/nitinol self-expanding stent-graft) (n = 97) for stenoses or occlusions of the SFA that were 13 cm long or shorter. At baseline, there were no significant differences between the PTA and stent-graft treatment groups, including chronic limb ischemia status and treated lesion length.The stent-graft group had a significantly higher technical success rate (95% vs 66%, P < .0001) and 1-year primary vessel patency rate at duplex ultrasonography (65% vs 40%, P = .0003). A patency benefit was seen for lesions at least 3 cm long. At 12 months, chronic limb ischemia status was 15% further improved for the stent-graft group (P = .003). There were no significant differences between treatment groups with regard to the occurrence of early or late major adverse events.In this multicenter study, the patency, technical success, and clinical status results obtained with stent-grafts were superior to those obtained with PTA alone.

    View details for DOI 10.1016/j.jvir.2008.02.008

    View details for Web of Science ID 000256416300004

    View details for PubMedID 18503895

  • The endograft pipeline JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Dake, M. D. 2008; 19 (6): S68-S70


    Thoracic endograft technology was initially designed and used clinically for descending thoracic aortic aneurysms. These devices have now been applied to more varied and complex thoracic aortic pathologic processes. Newer devices are being developed with the aim of improved suitability for these new challenges. This article provides a review of thoracic endografts likely to be available for use in the near future.

    View details for DOI 10.1016/j.jvir.2008.03.008

    View details for Web of Science ID 000256523100012

    View details for PubMedID 18502390

  • The 2007 Charles T. Dotter lecture - Our rock and our hard place: Getting beyond competition to collaboration JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Dake, M. D. 2008; 19 (6): 791-797

    View details for DOI 10.1016/j.jvir.2008.03.013

    View details for Web of Science ID 000256416300001

    View details for PubMedID 18503892

  • Endovascular management of thoracic dissections CIRCULATION Swee, W., Dake, M. D. 2008; 117 (11): 1460-1473
  • International controlled clinical trial of thoracic endovascular aneurysm repair with the Zenith TX2 endovascular graft: 1-year results 19th Annual Meeting of the American-Venous-Forum Matsumura, J. S., Cambria, R. P., Dake, M. D., Moore, R. D., Svensson, L. G., Snyder, S. MOSBY-ELSEVIER. 2008: 247–57


    This trial evaluated the safety and effectiveness of thoracic endovascular aortic repair (TEVAR) with a contemporary endograft system compared with open surgical repair (open) of descending thoracic aortic aneurysms and large ulcers.Forty-two international trial sites enrolled 230 subjects with descending thoracic aortic aneurysms or ulcers. The study compared 160 TEVAR subjects treated with the Zenith TX2 Endovascular Graft (William Cook Europe, ApS, Bjaeverskov, Denmark) with 70 open subjects. Subjects were evaluated preprocedure, predischarge, 1, 6, and 12 months, and yearly through 5 years with medical examination, laboratory testing, chest radiographs, and computed tomography scans. Mortality rates, prespecified severe morbidity composite index, major morbidity, clinical utility, aneurysm rupture, and secondary interventions were compared. The TEVAR subjects were evaluated by a core laboratory for device performance, including change in aneurysm size, endoleak, migration, and device integrity.The 30-day survival rate was noninferior (P < .01) for the TEVAR group compared with the open group (98.1% vs 94.3%). The severe morbidity composite index was lower for TEVAR (0.2 +/- 0.7 vs 0.7 +/- 1.2; P < .01). Cumulative major morbidity scores were significantly lower at 30 days for the TEVAR group compared with the open group (1.3 +/- 3.0 vs 2.9 +/- 3.6, P < .01). The TEVAR patients had fewer cardiovascular, pulmonary, and vascular adverse events, although neurologic events were not significantly different. Clinical utility for the TEVAR patients was superior to that of the open patients. No ruptures or conversions occurred in the first year. Reintervention rates were similar in both groups. At 12 months, aneurysm growth was identified in 7.1% (8/112), endoleak in 3.9% (4/103), migration (>10 mm) in 2.8% (3/107), and other device issues were rare. None of the patients with migration experienced endoleak, aneurysm growth, or required a secondary intervention.Thoracic endovascular aortic repair with the TX2 is a safer and effective alternative to open surgical repair for the treatment of anatomically suitable descending thoracic aortic aneurysms and ulcers at 1 year of follow-up. Device performance issues are infrequent, but careful planning and regular follow-up with imaging remain a necessity.

    View details for DOI 10.1016/j.jvs.2007.10.032

    View details for Web of Science ID 000252685000001

    View details for PubMedID 18241743

  • Portosystemic pressure gradient during transjugular intrahepatic portosystemic shunt with Viatorr stent graft: what is the critical low threshold to avoid medically uncontrolled low pressure gradient related complications? Journal of gastroenterology and hepatology Chung, H., Razavi, M. K., Sze, D. Y., Frisoli, J. K., Kee, S. T., Dake, M. D., Hellinger, J. C., Kang, B. 2008; 23 (1): 95-101


    Inappropriately decreased portosystemic pressure gradient (PSG) during transjugular intrahepatic portosystemic shunt (TIPS) can cause fatal complications but the critical low threshold of PSG is still not clear. The aim of the present study was to evaluate the critical low threshold of PSG during TIPS.Sixty-six patients with cirrhosis who successfully underwent de novo TIPS with Viatorr stent grafts were studied. Medically uncontrolled low pressure gradient (LPR) complication was defined as when a patient died, or when acute transplantation or a TIPS reduction procedure was performed due to refractory encephalopathy or the deterioration of hepatic function within 3 months after the procedure. For the determination of the risk group for medically uncontrolled LPR complications, the Child-Pugh score and the model of end-stage liver disease (MELD) score showing a 100% negative predictive value was decided on as a threshold for each score. The risk group was defined when either of both scores was higher than its threshold. For the determination of a critical low post-TIPS PSG, a value of post-TIPS PSG showing the highest discrimination power on the receiver operating characteristic (ROC) curve in the risk group was decided on as a critical low threshold of PSG. The medically uncontrolled LPR complication rates of the patients with the determined threshold or lower were evaluated for the risk group.Medically uncontrolled LPR complications developed in nine patients (13.6%). Five patients died and four patients had TIPS reduction procedures. Patients with more than 10 on the Child-Pugh score or more than 14 on the MELD score were determined to be the risk group and 34 patients were included. The critical lower threshold of the post-TIPS PSG showing the highest discrimination power on the ROC curve was 5 mmHg (sensitivity 100%, specificity 72%), and the medically uncontrolled LPR complication rates of the patients with 5 mmHg or lower on the post-TIPS PSG were 56.3% (9/16) in the risk group.The critical threshold of the post-TIPS PSG to avoid the medically uncontrolled LPR complications of TIPS was >5 mmHg. The PSG should not be reduced below this level in the risk group.

    View details for DOI 10.1111/j.1440-1746.2006.04697.x

    View details for PubMedID 18171347

  • Imaging of the thoracic aorta before and after stent-graft repair of aneurysms and dissections. Seminars in thoracic and cardiovascular surgery Ueda, T., Fleischmann, D., Rubin, G. D., Dake, M. D., Sze, D. Y. 2008; 20 (4): 348-357


    Thoracic endovascular aortic repair (TEVAR) has become widely accepted as an important option for treatment of thoracic aortic diseases. Cross-sectional radiologic imaging plays a crucial role for evaluating a patient's candidacy for planning of the intervention and for assessment of postprocedural results and complications of TEVAR. Recent advances in imaging technologies, in part inspired by advances in stent-graft technology, have drastically changed the character and role of pre- and postprocedural imaging. Three-dimensional (3D) datasets acquired quickly by multidetector computed tomography (MDCT), angiography, or magnetic resonance angiography (MRA) allow multiplanar reformations and 3D viewing, as well as quantitative assessment of vessel lumens, walls, and surroundings. Catheter angiography, in contrast, is performed intraoperatively almost exclusively, and is no longer the gold standard for diagnostic or planning purposes. This article reviews state-of-the-art pre- and postprocedural imaging for TEVAR, especially focusing on the role of MDCT angiography.

    View details for DOI 10.1053/j.semtcvs.2008.11.008

    View details for PubMedID 19251176

  • Endovascular treatment of thoracic aortic disease: Mid-term follow-up CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS Tespili, M., Banfi, C., Valsecchi, O., Aiazzi, L., Ricucci, C., Guagliumi, G., Musumeci, G., Ferrazzi, P., Dake, M. D. 2007; 70 (4): 595-601


    The aim of this study was to evaluate the mid-term follow-up in a cohort of patients with acute or chronic descending aortic disease treated by stent-graft repair.Since 1999, endovascular stent-graft placement has been reported as an alternative treatment to surgical approach for a variety of thoracic aortic diseases; however, results beyond initial short-term follow-up are not widely available for the broad range of applications.From March 2001, 43 consecutive patients with traumatic aortic transection (group A = 16) and complicated type B aortic dissection or aneurysm (group B = 27) underwent stent-graft implantation. All patients underwent computed tomography (CT) scan as preoperative assessment and in 26 a transesophageal echo (TEE) exam was performed.Technically successful stent-graft deployment was achieved in all patients. No patient required surgical conversion and no cases of paraplegia occurred. The overall in-hospital mortality was 9.3%. A residual endoleak (type II) was detected in one group B patient who was managed conservatively. The mean follow-up was 29 +/- 8 months (range 10-48 months). No patient died during late follow-up after hospital discharge. At 12 months, one patient (2.5%) who had stent graft repair of an aortic dissection developed an asymptomatic type I endoleak. Three asymptomatic patients with chronic dissection had a persistent retrograde perfusion of the thoracic false lumen via a distal tear(s) in the dissection septum.Our results of stent-graft treatment of complicated and uncomplicated diseases of the descending aorta confirms that this alternative to open repair is a safe, less invasive, and relatively low risk approach. Medium-term follow-up results suggest that it is effective and durable therapy with low associated mortality and morbidity rates.

    View details for DOI 10.1002/ccd.21262

    View details for Web of Science ID 000250104300024

    View details for PubMedID 17621661

  • Reevaluating the need for left subclavian artery revascularization with thoracic endovascular aortic repair 43rd Annual Meeting of the Society-of-Thoracic-Surgeons Reece, T. B., Gazoni, L. M., Cherry, K. J., Peeler, B. B., Dake, M., Matsumoto, A. H., Angle, J., Kron, I. L., Tribble, C. G., Kern, J. A. ELSEVIER SCIENCE INC. 2007: 1201–5


    With increased utilization of thoracic endovascular aortic repair (TEVAR), the anatomic limitations of proximal device landing zones are being challenged. As our experience has grown with TEVAR involving exclusion of the left subclavian artery (LSA), the need for selective revascularization of the LSA appeared to be more common than we initially anticipated. We hypothesize that for patients undergoing TEVAR requiring coverage of the LSA, the need for LSA revascularization is higher than reported in the literature.The charts of all patients undergoing TEVAR performed at a single tertiary care center from 1999 to 2006 were reviewed. The review included the preoperative radiographic evaluations, the assessment of comorbidities, the anatomic position of the proximal and distal landing zones, outcomes, complications, and the need for preoperative or postoperative subclavian artery revascularization.Sixty-four patients underwent TEVAR and 27 (42%) of these patients required exclusion of the LSA from the thoracic aorta. Seven of these 27 patients (25.9%) required preoperative LSA revascularization. Four patients developed late symptoms, necessitating LSA revascularization. No patients died or developed paraplegia, but three adverse neurological events occurred unrelated to the posterior fossa circulation. No patient developed any left arm disability.The TEVAR coverage of the LSA with selective revascularization was safe for patients, but greater than 11 of 27 (40.7%) required either preoperative or postoperative LSA revascularization. Although this study represents our early experience with TEVAR, these data suggest that selective revascularization after TEVAR exclusion of the origin of the LSA may be required more frequently than previously reported.

    View details for DOI 10.1016/j.athoracsur.2007.05.020

    View details for Web of Science ID 000249595600022

    View details for PubMedID 17888970

  • Standardized evaluation and reporting of Stent fractures in clinical trials of noncoronary devices CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS Jaff, M., Dake, M., Pornpa, J., Ansel, G., Yoder, T. 2007; 70 (3): 460-462


    Define the prospective surveillance and reporting parameters for assessment of metallic stents used in clinical trials of superficial femoral artery atherosclerosis.While advances in medical therapies to improve atherosclerotic risk factor profiles in patients with peripheral arterial disease have focused on prevention of disease progression, the development of endovascular devices is altering the therapeutic algorithm for patients with peripheral arterial disease. Stents have emerged as one of the advances that may promote durable patency, particularly in the infrainguinal arteries.The Zilver-PTX is a prospective multicenter randomized trial of bare metal versus drug-eluting nitinol stents for superficial femoral artery peripheral arterial disease. A predefined surveillance program is mandated in this trial. During the genesis of this program, it became clear that no single standard has existed to identify, classify, and report fractures of metallic stents placed in peripheral arteries.This report defines the key components of prospective stent fracture surveillance, including location of radiographic images obtained, types of radiographic equipment, methods of limb, and image intensifier positioning, intervals required for imaging, grading schemes for reporting, and methods of analyzing the images.As the proliferation of minimally invasive revascularization strategies continues, the stability of metallic endoprostheses is increasingly critical. Uniform surveillance of these devices for fracture and disarticulation is important in order to compare the relative merits of various stent-based devices in clinical trials.

    View details for DOI 10.1002/ccd.21240

    View details for Web of Science ID 000249233200022

    View details for PubMedID 17559108

  • Traumatic ascending aortopulmonary window following pulmonary artery stent dilatation: Therapy with aortic endovascular stent graft PEDIATRIC CARDIOLOGY Ailawadi, G., Lim, D. S., Peeler, B. B., Matsumoto, A. H., Dake, M. D. 2007; 28 (4): 305-308


    Endovascular stent grafts have become an established therapy in adults for descending thoracic aortic disease. We report a case of a 13-year-old boy with a hemodynamically significant traumatic aortopulmonary window following angioplasty of pulmonary artery stent. Endovascular stent graft implantation into the ascending aorta was performed to seal off the communication, with dramatic hemodynamic improvement.

    View details for DOI 10.1007/s00246-006-0118-9

    View details for Web of Science ID 000247464700014

    View details for PubMedID 17530323

  • Stent graft management of stable, uncomplicated type B aortic dissection. Perspectives in vascular surgery and endovascular therapy Kahn, S. L., Dake, M. D. 2007; 19 (2): 162-169


    Aortic dissection has an incidence of 2.6 to 3.5 per 100,000 person years. Although the traditional approach has focused on surgical and medical intervention, several studies demonstrate the efficacy of endovascular repair for aortic dissection. Bolstered by a high technical success rate and improved morbidity and mortality relative to its surgical counterpart, endovascular repair has become a first-line treatment for complicated type B aortic dissection. The debate over the optimal approach to uncomplicated type B dissection is more contentious. The consensus remains in support of medical therapy tailored for tight control of hypertension. The poor long-term results of this regimen, with up to 50% mortality at 5 years, have shifted attention to endovascular stent grafting as an alternative. This article reviews the latest research on uncomplicated type B dissection and its treatment, concentrating on endovascular technique, anatomic considerations, timing of intervention, and outcomes. Early research indicates endovascular stent grafting is a promising modality for these patients.

    View details for PubMedID 17704486

  • Massive pulmonary embolus with hemodynamic compromise: therapeutic options. Emergency radiology Lohan, D. G., Cronin, C. G., Meehan, C. P., Kee, S. T., Dake, M. D., Davidson, I. R., O'Sullivan, G. J. 2007; 13 (4): 161-169


    Recent advances in pharmacotherapeutics and interventional techniques have resulted in resurgence in interest regarding the optimal means of management of hemodynamically significant pulmonary embolic disease. However, these various techniques have many associated disadvantages, and it is of paramount importance that the responsible physician has a detailed understanding of each of these so that the appropriate intervention be requested and performed. By way of background discussion and relevant cases in point, we consider each of these management options in turn, with particular reference to the advantages, disadvantages, and application of each.

    View details for PubMedID 17115098

  • Molecular imaging: A primer for interventionalists and imagers JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, D. S., Dake, M. D., Park, J. M., Kuo, M. D. 2006; 17 (9): 1405-1423


    The characterization of human diseases by their underlying molecular and genomic aberrations has been the hallmark of molecular medicine. From this, molecular imaging has emerged as a potentially revolutionary discipline that aims to visually characterize normal and pathologic processes at the cellular and molecular levels within the milieu of living organisms. Molecular imaging holds promise to provide earlier and more precise disease diagnosis, improved disease characterization, and timely assessment of therapeutic response. This primer is intended to provide a broad overview of molecular imaging with specific focus on future clinical applications relevant to interventional radiology.

    View details for DOI 10.1097/01.RVI.0000235746.86332.DF

    View details for Web of Science ID 000240883100004

    View details for PubMedID 16990461

  • Virtual Angioscopy in type A dissection: Ascending aortic stent-graft repair ANNALS OF THORACIC SURGERY Verhoye, J., Sze, D. Y., Ihnken, K., Hellinger, J. C., Robbins, R. R., Dake, M. D. 2006; 82 (1): 347-347
  • Stent-graft repair of an aortic rupture caused by invasive hemangiopericytoma ANNALS OF THORACIC SURGERY van der Starre, P. J., Sze, D. Y., Guta, C., Mitchell, R. S., Dake, M. D. 2006; 81 (6): 2300-2302


    We describe a patient with a history of hemangiopericytoma, who had hemoptysis develop due to a pseudoaneurysm of the thoracic aorta from an intrathoracic metastasis. Stent-graft repair successfully excluded the aneurysm from the aorta. Transesophageal echocardiography showed to be an important guide for correct placement of the device.

    View details for DOI 10.1016/j.athoracsur.2005.07.016

    View details for Web of Science ID 000238027600059

    View details for PubMedID 16731179

  • Thoracic aortic endografting is the treatment of choice for elderly patients with thoracic aortic disease 117th Annual Meeting of the Southern-Surgical-Association Kern, J. A., Matsumoto, A. H., Tribble, C. G., Gazoni, L. M., Peeler, B. B., Harthun, N. L., Chong, T., Cherry, K. J., Dake, M. D., Angle, J. S., Kron, I. L. LIPPINCOTT WILLIAMS & WILKINS. 2006: 815–23


    To assess the effect of age on outcomes following thoracic aortic endografting.Endograft therapy for thoracic aortic disease is rapidly evolving. This therapy is less invasive, and elderly patients with significant medical comorbidities are more frequently referred for endografting. We hypothesized that elderly patients over the age of 75 have worse outcomes after thoracic endografting than patients under the age of 75.We retrospectively reviewed the charts of the first 42 patients who underwent endografting for thoracic aortic pathology. Charts were reviewed for demographics, comorbid conditions, perioperative complications and death, endoleaks, and results at 3, 6, and 12 months. Preexisting medical conditions were also evaluated to determine if any patient characteristics were associated with adverse outcomes. Perioperative morbidity included cardiac, pulmonary, renal, hemorrhagic, and neurologic (stroke and spinal cord injury) complications.Twenty-four patients were under the age of 75, and 18 patients were 75 or older. Baseline demographics and comorbidities were similar between the 2 groups. There were no differences in operative time, length of stay, perioperative mortality, or the incidence of significant complications between the 2 age groups. Gender, however, was associated with a statistically significant difference between the occurrence of complications, with more women experiencing complications than men (P = 0.026, relative risk = 2.36). One patient (age >75 years) in the entire cohort of 42 (2.4%) suffered a spinal cord injury. At 3 months, endoleaks were more common in the older age group (P = 0.059).Endograft therapy for thoracic aortic disease can be performed safely in elderly patients with no significant increase in perioperative morbidity or mortality compared with younger patients. Female gender is associated with a higher likelihood of perioperative complications, regardless of age. The overall incidence of spinal cord injury is very low. Endograft therapy, when anatomically possible, is the treatment of choice for thoracic aortic disease in elderly patients.

    View details for DOI 10.1097/01.sla.0000219736.33478.ea

    View details for Web of Science ID 000237962600020

    View details for PubMedID 16772785

  • Clinical competence statement on thoracic endovascular aortic repair (TEVAR) - Multispecialty consensus recommendations - A report of the SVS/SIR/SCAI/SVMB Writing Committee to develop a clinical competence standard for TEVAR JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Hodgson, K. J., Matsumura, J. S., Ascher, E., Dake, M. D., Sacks, D., Krol, K., Bersin, R. 2006; 17 (4): 617-621
  • Clinical competence statement on thoracic endovascular aortic repair (TEVAR)--multispecialty consensus recommendations. A report of the SVS/SIR/SCAI/SVMB Writing Committee to develop a clinical competence standard for TEVAR. Journal of vascular surgery Hodgson, K. J., Matsumura, J. S., Ascher, E., Dake, M. D., Sacks, D., Krol, K., Bersin, R. M. 2006; 43 (4): 858-862

    View details for PubMedID 16616253

  • Will stent-graft repair emerge as treatment of choice for acute type B dissection? SEMINARS IN VASCULAR SURGERY Dake, M. D., Wang, D. S. 2006; 19 (1): 40-47


    Endovascular stent grafts are now accepted globally and approved by the US Food and Drug Administration as an alternative to open surgical repair for patients with descending thoracic aortic aneurysm. However, as opposed to the abdominal aorta, application of this technology to manage thoracic aortic disease is not limited to degenerative aneurysms. In fact, international registries and surveys estimate that only 60% of the thoracic cases managed currently with stent-graft placement are aneurysms. The remainder of this experience includes acute dissection, chronic dissection, traumatic aortic injury, penetrating ulcer, intramural hematoma, aortic fistula, anastomotic pseudoaneurysm, and an embolizing lesion. In this regard, it is important to keep in mind that the present devices used in these nonaneurysmal applications are not designed to address the unique anatomical and pathological features that these lesions present. Consequently, in the future, it is possible that we will see stent-graft designs that focus specifically on the challenges of some of the nonaneurysmal thoracic aortic pathologies.

    View details for DOI 10.1053/j.semvascsurg.2005.11.007

    View details for Web of Science ID 000242239900007

    View details for PubMedID 16533691

  • Directed migration of smooth muscle cells to engineer plaque-resistant vein grafts JOURNAL OF ENDOVASCULAR THERAPY Amabile, P. G., Wang, D. S., Kao, E. Y., Lee, J., Elkins, C. J., Yuksel, E., Hilfiker, P. R., Waugh, J. M., Dake, M. D. 2005; 12 (6): 667-675


    To test the hypothesis that controlled perivascular release of tissue plasminogen activator (tPA) can generate cleaved extracellular matrix (ECM) chemotactic gradients to guide the migration of vascular smooth muscle cells (SMCs) away from the lumen, thereby limiting neointima formation.This hypothesis was tested in rabbit models in which the perivascular surface of vein bypass grafts was treated with microspheres releasing tPA (MS-tPA), microspheres containing no drug (MS-blank), or phosphate buffered saline (PBS). Vein graft segments harvested after 7 days were then evaluated for elastin content, proliferating SMCs, intima-to-media (I/M) ratio, and inflammation; late impact on neointima formation was also examined.The 7-day results demonstrated cleaved elastin gradients and proliferating SMCs that assumed a more peripheral distribution in the MS-tPA group than MS-blank and PBS controls (p<0.05). At 28 days, vein grafts treated with MS-tPA showed a mean I/M ratio (0.35+/-0.04) that was 63.5% lower than PBS controls (0.96+/-0.07, p<0.005) and 43.5% lower than MS-blank specimens (0.62+/-0.08, p<0.05).Perivascular release of tPA modifies ECM gradients, directionally guides SMC migration away from the lumen, and limits neointima formation.

    View details for Web of Science ID 000234188800007

    View details for PubMedID 16363896

  • Endovascular repair of abdominal and thoracic aortic aneurysms CIRCULATION Katzen, B. T., Dake, M. D., MaClean, A. A., Wang, D. S. 2005; 112 (11): 1663-1675
  • Multi-institutional pivotal trial of the Zenith TX2 thoracic aortic stent-graft for treatment of descending thoracic aortic aneurysms: clinical study design. Perspectives in vascular surgery and endovascular therapy Hassoun, H. T., Dake, M. D., Svensson, L. G., Greenberg, R. K., Cambria, R. P., Moore, R. D., Matsumura, J. S. 2005; 17 (3): 255-264


    Despite significant improvements in surgical techniques and perioperative management, the repair of descending thoracic aortic aneurysms remains a challenge with the potential for substantial morbidity and mortality. Over the past several years, buoyed by the technical success of endovascular repair of infrarenal abdominal aortic aneurysms, several case series reports of endovascular stent-graft placement for descending thoracic aortic aneurysms have demonstrated the potential safety and efficacy of this treatment modality. Several single-institution studies have documented promising results with these devices, but without controlled clinical trials, the data are insufficient to determine if thoracic aortic endografts provide equivalent or improved outcomes compared with standard open repair. We describe a study design of an ongoing prospective, nonrandomized, multi-institutional, investigational device exemption phase II pivotal clinical trial investigating the safety and effectiveness of the Zenith TX2 thoracic aortic endovascular graft in the elective treatment of patients with descending thoracic aortic aneurysms.

    View details for PubMedID 16273168

  • Treatment of hepatic venous outflow obstruction after piggyback liver transplantation RADIOLOGY Wang, S. L., Sze, D. Y., Busque, S., Razavi, M. K., Kee, S. T., Frisoli, J. K., Dake, M. D. 2005; 236 (1): 352-359


    To evaluate retrospectively the endovascular management of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation.The study was performed with the approval and under the guidelines of the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent from patients was not required by the institutional review board for this retrospective study. From 1995 to 2003, 13 patients (eight male, five female), including 12 adults and one adolescent (age range, 14-67 years; median age, 52 years), underwent endovascular treatment of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation. Patients gave informed consent for all procedures. Eleven patients received whole livers, and two received living-related donor right liver lobes. Four underwent repeat piggyback orthotopic liver transplantation prior to intervention. Primary stent placement was performed in 12 patients. One patient refused primary stent placement and chose venoplasty alone, but required a stent 5 months later. Short balloon-expandable stents (mean diameter, 14.6 mm +/- 1.1 [standard deviation]) were used to minimize jailing of branch vessels and to resist recoil. Pre- and post-procedural pressure gradients were measured. Follow-up included venography, cross-sectional imaging, and laboratory tests. The Wilcoxon signed rank test or the sign test was performed to compare pre- and post-procedural pressure gradients, body weights, and laboratory values.Technical success (pressure gradient < or = 3 mm Hg) was achieved in 13 of 13 patients, and clinical success, in 12 of 13. Mean pre- and post-procedural pressure gradients were 13.0 mm Hg +/- 1.4 and 0.8 mm Hg +/- 0.3. Mean interval from transplantation to intervention was 348 days +/- 159. Mean follow-up was 678 days (range, 16-2880 days). Technical success did not result in clinical improvement in one patient. Biopsy demonstrated severe hepatic necrosis, likely from prolonged venous congestion, and the patient required repeat transplantation. Only one patient required reintervention for stent migration, and no other complications occurred. No significant restenosis was encountered after stent placement.Hepatic venous outflow obstruction is an uncommon but potentially fatal complication of piggyback orthotopic liver transplantation. Endovascular treatment with balloon-expandable stents is effective, safe, and apparently durable.

    View details for DOI 10.1148/radiol.2361040327

    View details for Web of Science ID 000229905300046

    View details for PubMedID 15955856

  • Multiple HIV-related aneurysms: Open and endovascular treatment JOURNAL OF ENDOVASCULAR THERAPY Heikkinen, M. A., Dake, M. D., Alsac, J. M., Zarins, C. K. 2005; 12 (3): 405-410


    To report successful endovascular repair of thoracic aortic aneurysms in 2 patients with human immunodeficiency virus (HIV).Thoracic and abdominal aortic aneurysms (AAA) were found in a 60-year-old woman 1 year after she was diagnosed with HIV. Because of pain and risk of rupture, the AAA was repaired with conventional open techniques in February 1997, while the thoracic aneurysm was excluded in a staged procedure using a homemade endograft delivered through a 10-mm conduit sewn to the aortic tube graft. Two months later, new aneurysms were found in the superficial femoral arteries bilaterally; both were excised and replaced with vein grafts. After 7 years, the patient is well and no longer takes antiretroviral medication. Surveillance imaging shows continued patency of the stent-graft without evidence of leak or migration. In a more contemporary case, a 46-year-old man was found to have 5 focal aneurysms in the aorta; the most proximal descending thoracic aneurysm increased 2 cm in 2 weeks. The two thoracic aneurysms were successfully excluded using 2 Excluder stent-grafts. At 7 months, he was doing well, and the aneurysm had shrunk 11 mm.Endovascular and open treatment of HIV-related aneurysms is possible, with excellent long-term results. Patients with long-life expectancy should be treated according to the same guidelines as patients without HIV.

    View details for Web of Science ID 000229874600020

    View details for PubMedID 15943519

  • Portal hypertensive hemorrhage from a left gastroepiploic vein caput medusa in an adhesed umbilical hernia. Journal of vascular and interventional radiology Sze, D. Y., Magsamen, K. E., McClenathan, J. H., Keeffe, E. B., Dake, M. D. 2005; 16 (2): 281-285


    Caput medusa is a frequent incidental finding in patients with portal hypertension that usually represents paraumbilical vein portosystemic collateral vessels draining into body wall systemic veins. A symptomatic caput medusa was seen in a morbidly obese patient after an umbilical hernia repair, which was fed not by the left portal vein but by the left gastroepiploic vein, in a recurrent adhesed umbilical hernia that likely contained herniated omentum. Refractory hemorrhage from this caput medusa was successfully treated by transjugular intrahepatic portosystemic shunt creation and balloon-occluded variceal sclerosis.

    View details for PubMedID 15713931

  • MR-guided transjugular intrahepatic portosystemic shunt creation with use of a hybrid radiography/MR system 29th Annual Meeting of the Society-of-Interventional-Radiology (SIR) Kee, S. T., GANGULY, A., Daniel, B. L., Wen, Z. F., Butts, K., Shimikawa, A., Pelc, N. J., Fahrig, R., Dake, M. D. ELSEVIER SCIENCE INC. 2005: 227–34


    To evaluate the performance of a combined hybrid radiography/magnetic resonance (MR) unit to guide portal vein (PV) puncture during human transjugular intrahepatic portosystemic shunt (TIPS) creation.Fourteen patients undergoing TIPS creation were studied during standard clinical applications. Patients were anesthetized and then positioned in an open MR unit containing a flat-panel radiographic fluoroscopic unit. With use of a combination of fluoroscopy and MR imaging, the PV was accessed and the TIPS procedure was performed. A noncovered nitinol stent or a covered stent-graft was placed in the TIPS tract. Number of punctures required, total procedure time, fluoroscopy time, procedural success rate, complications, and ultrasonographic and clinical follow-up were recorded.Clinical success was obtained in 13 of 14 patients. In one patient, extrahepatic puncture of the PV occurred, resulting in hemorrhage and requiring placement of a covered stent to control the bleeding. The mean number of punctures required to access the PV was 2.6 +/- 1.7, and the total procedure time was 2.5 hours +/- 0.6. Mean fluoroscopy time was 22.3 minutes +/- 5.5. Results of clinical and ultrasonographic follow-up compare favorably to previously published reports.TIPS creation with a combination hybrid radiography/MR unit is feasible and may reduce the number of needle passes required and radiation exposure, with similar overall outcomes compared with studies reported in the literature.

    View details for DOI 10.1097/01.RVI.0000143766.08029.6E

    View details for Web of Science ID 000227710000009

    View details for PubMedID 15713923

  • Liver tissue engineering at extrahepatic sites in mice as a potential new therapy for genetic liver diseases HEPATOLOGY Ohashi, K., Waugh, J. M., Dake, M. D., Yokoyama, T., Kuge, H., Nakajima, Y., Yamanouchi, M., Naka, H., Yoshioka, A., Kay, M. A. 2005; 41 (1): 132-140


    Liver tissue engineering using hepatocyte transplantation has been proposed as an alternative to whole-organ transplantation or liver-directed gene therapy to correct various types of hepatic insufficiency. Hepatocytes are not sustained when transplanted under the kidney capsule of syngeneic mice. However, when we transplanted hepatocytes with the extracellular matrix components extracted from Engelbreth-Holm-Swarm cells, hepatocytes survived for at least 140 days and formed small liver tissues. Liver engineering in hemophilia A mice reconstituted 5% to 10% of normal clotting activity, enough to reduce the bleeding time and have a therapeutic benefit. Conversely, the subcutaneous space did not support the persistent survival of hepatocytes with Engelbreth-Holm-Swarm gel matrix. We hypothesized that establishing a local vascular network at the transplantation site would reduce graft loss. To test this idea, we provided a potent angiogenic agent before hepatocyte transplantation into the subcutaneous space. With this procedure, persistent survival was achieved for the length of the experiment (120 days). To establish that these engineered liver tissues also retained their native regeneration potential in vivo, we induced two different modes of proliferative stimulus to the naive liver and confirmed that hepatocytes within the extrahepatic tissues regenerated with activity similar to that of naive liver. In conclusion, our studies indicate that liver tissues can be engineered and maintained at extrahepatic sites, retain their capacity for regeneration in vivo, and used to successfully treat genetic disorders.

    View details for DOI 10.1002/hep.20484

    View details for Web of Science ID 000226245000019

    View details for PubMedID 15619229

  • Local resistance to oxidative stress by overexpression of copper-zinc superoxide dismutase limits neointimal formation after angioplasty JOURNAL OF ENDOVASCULAR THERAPY Kuo, M. D., Bright, I. J., Wang, D. S., Ghafouri, P., Yuksel, E., Hilfiker, P. R., Miniati, D. N., Dake, M. D. 2004; 11 (6): 585-594


    To examine the effects of oxidative stress on neointimal hyperplasia through local overexpression of human copper-zinc superoxide dismutase (Cu-Zn SOD).The left common femoral arteries (CFA) of 18 New Zealand white rabbits were subjected to balloon overdilation injury. Each dilated CFA was then incubated with either a nonviral (buffer) or viral (adenovirus overexpressing beta-galactosidase) control or an adenovirus overexpressing Cu-Zn SOD. Animals were then sacrificed at 3, 7, or 28 days (3 arteries per group per time point) and the treated CFA segments were harvested for analysis of esterase-positive inflammatory cells and extracellular matrix elements. The intima-to-media ratio (I/M) was measured to assess the degree of neointimal formation.At 3 days, local SOD levels in the Cu-Zn SOD-treated group were significantly elevated relative to both controls (p<0.01). Significant reductions in lipid peroxidation byproducts were also seen in the SOD group relative to viral and nonviral controls (p<0.05). Mean I/M at 28 days was 0.582+/-0.088 for the nonviral control group versus 0.565+/-0.133 for the viral control group. The SOD-treated group had a significant reduction relative to both controls: 0.259+/-0.045 (p<0.05). Statistically significant reductions in I/M were also demonstrated in the SOD group relative to control groups at 7 days (p<0.05). The SOD-treated group demonstrated significant preservation of elastin relative to controls, as well as a significant reduction in esterase-positive granulocytes relative to controls (p<0.05).Direct buffering of oxidative stress in balloon-injured vessels can significantly alter postinjury response and limit neointimal hyperplasia.

    View details for Web of Science ID 000226315200002

    View details for PubMedID 15615548

  • Efficient inhibition of in-stent restenosis by controlled stent-based inhibition of elastase: A pilot study JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Ganaha, F., Ohashi, K., Do, Y. S., Lee, J., Sugimoto, K., Minamiguchi, H., Elkins, C. J., Sameni, D., Modanlou, S., Kao, E. Y., Kay, M. A., Waugh, J. M., Dake, M. D. 2004; 15 (11): 1287-1293


    It is proposed that local elastase inhibition could suppress the extracellular matrix (ECM) degradation and subsequent smooth muscle cell migration and limit subsequent in-stent restenosis. This study evaluated the effect of stent-based controlled elastase inhibition on restenosis after stent implantation in a rabbit model.Biodegradable microspheres containing the potent elastase inhibitor alpha-1-antitrypsin (AAT) were prepared. Daily release of AAT from the microspheres was confirmed in vitro. The microspheres were loaded into stents with an abluminal polymer reservoir. Implantation of the stent with AAT microspheres and blank microspheres (control) was performed in the abdominal aortae of six rabbits in each group. After stent deployment, all stents were overdilated to 125% diameter. Stent-implanted arteries were harvested after 7 days (n = 3 each) or 28 days (n = 3 each). To assess the effect of local delivery of AAT, elastase activity and elastin content of the stent-implanted aortae were analyzed. As an endpoint, intima-to-media (I/M) ratio was determined in the 7-day and 28-day specimens.Significant inhibition of elastase was confirmed in treated vessels versus controls at 7 days after stent implantation (P < .05). This reduction in elastase activity was sufficient to afford early and late reduction of in-stent neointima. Plaque progression in the 28-day specimens decreased to 67% with elastase inhibition relative to controls (P < .05).Stent-based controlled release of elastase inhibitor may significantly reduce ECM degradation and might limit in-stent restenosis.

    View details for DOI 10.1097/01.RVI.0000141340.67588.4F

    View details for Web of Science ID 000227678800014

    View details for PubMedID 15525749

  • Stent-graft treatment of extracranial carotid and vertebral arterial lesions JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Saket, R. R., Razavi, M. K., Sze, D. Y., Frisoli, J. K., Kee, S. T., Dake, M. D. 2004; 15 (10): 1151-1156


    Five patients with pseudoaneurysms of the carotid artery (n = 4) and an arteriovenous fistula of the vertebral artery (n = 1) were treated with stent-grafts. Commercially made devices were used in all but one of the patients. In four of the five patients, the pathology was successfully excluded. One patient had a small type-I endoleak. There were no immediate procedure-related complications or neurologic sequalae. All experienced immediate resolution of symptoms. One patient was lost to follow-up after discharge and another died 2 weeks after intervention. The remaining patients remained asymptomatic with patent stent-grafts after follow-up periods of 14, 16, and 46 months, respectively.

    View details for DOI 10.1097/01.RVI.0000134496.71252

    View details for Web of Science ID 000227678700018

    View details for PubMedID 15466804

  • The value of transesophageal echocardiography for endovascular graft stenting of the ascending aorta JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA van der Starre, P., Guta, C., Dake, M., Ihnken, K., Robbins, R. 2004; 18 (4): 466-468

    View details for DOI 10.1053/j.jvca.2004.05.027

    View details for Web of Science ID 000224223500014

    View details for PubMedID 15365930

  • TIPS reduction with use of stents or stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Saket, R. R., Sze, D. Y., Razavi, M. K., Kee, S. T., Frisoli, J. K., Semba, C. P., Dake, M. D. 2004; 15 (7): 745-751


    This report describes new techniques to perform TIPS reduction in patients with post-TIPS complications. Methods included hourglass-shaped stents and stent-grafts, and parallel stents and stent-grafts. All procedures were technically successful, resulting in increased portosystemic gradients and decreased symptoms, although patient outcomes were mixed. None of the patients experienced recurrent variceal hemorrhage or ascites in short-term follow-up. Stent-grafts have the advantage of immediate exclusion of blood flow outside the reducing stent, resulting in an immediate reduction of the caliber of the shunt. Techniques that allow fine adjustment of shunt diameters may have further advantages.

    View details for DOI 10.1097/01.RVI.0000133526.80425.16

    View details for Web of Science ID 000227678400012

    View details for PubMedID 15231889

  • Stent-based controlled release of intravascular angiostatin to limit plaque progression and in-stent restenosis JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Ganaha, F., Kao, E. Y., Wong, H., Elkins, C. J., Lee, J., Modanlou, S., Rhee, C., Kuo, M. D., Yuksel, E., Cifra, P. N., Waugh, J. M., Dake, M. D. 2004; 15 (6): 601-608


    To evaluate the importance of angiogenesis in plaque progression after stent placement, this study examines stent-based controlled delivery of the antiangiogenic agent, angiostatin, in a rabbit model.Controlled release biodegradable microspheres delivering angiostatin or polymer-only microspheres (polylactic-co-glycolic-acid-polyethylene glycol; PLGA/PEG) were loaded in channeled stents, anchored, and deployed in the aorta of adult New Zealand white rabbits (n = 6 animals per group, three each per time point). The stented aortas were harvested at 7 days and 28 days and evaluated for neovascularization, local inflammation, vascular smooth muscle cell proliferation, and in-stent plaque progression.At 7 days, neovascularization was significantly decreased in the angiostatin groups (1.6 +/- 1.6 neovessels per mm(2) plaque) versus the control group (15.4 +/- 2.6 neovessels per mm(2) plaque; P =.00081), as were local inflammation where angiostatin-treated groups demonstrated significantly lower macrophage recruitment per cross section (34.9 +/- 4.9 cells per cross section) relative to the control group (55.2 +/- 3.84 cells per cross section; P =.0037). And a significant decrease in the overall vascular smooth muscle cell proliferation (143.8 +/- 26.3 Ki-67 positive cells per mm(2)) relative to the control group (263.2 +/- 16.6 Ki-67 positive cells per mm(2); P =.00074). At both 7 and 28 days, in-stent plaque progression in the angiostatin groups was successfully limited relative to the control group by 54% (0.255 +/- 0.019% of cross section; P =.00016) and 19% (1.981 +/- 0.080; P =.0033) respectively and resulted in reduction of in-stent restenosis relative to the control group.Angiostatin-eluting stents may limit neovascularity after arterial implantation, offer insight into in-stent restenosis, and allow future refinement of bioactive stent designs and clinical strategies, particularly in light of evidence that intimal smooth muscle cells may in part be marrow-derived.

    View details for DOI 10.1097/01.RVI.0000127888.70058.93

    View details for Web of Science ID 000227678200011

    View details for PubMedID 15178721

  • Thrombolysis for lower extremity deep venous thrombosis. Techniques in vascular and interventional radiology Semba, C. P., Razavi, M. K., Kee, S. T., Sze, D. Y., Dake, M. D. 2004; 7 (2): 68-78


    Catheter-directed thrombolysis (CDT) has been proposed as an alternative mode of therapy to anticoagulation in patients with massive, symptomatic deep vein thrombosis of the extremity. The major goal of therapy is to rapidly restore venous blood flow, reduce the pain and edema of the extremity, preserve venous valve function, and reduce chronic symptoms related to chronic venous hypertension (postthrombotic syndrome). In patients with iliofemoral deep venous thrombosis (DVT) standard angiographic techniques are used to instrument a lower extremity vein (popliteal) and venography is performed followed by catheter-directed infusion of a plasminogen activator directly into the thrombus. Following lytic infusion, the interventionalist must evaluate the venous drainage to determine if there is an anatomic lesion that requires further endovascular treatment (eg, iliac vein compression syndrome). Posttreatment therapy usually consists of warfarin therapy and venous compression stockings for at least 3 to 6 months. The purpose of this article is to review the technical approach used in treating iliofemoral DVT and highlight the hurdles that face interventionalists in attempting to broaden this procedure to most types of lower extremity DVT.

    View details for PubMedID 15252763

  • Novel intravascular ultrasound-guided method to create transintimal arterial communications: Initial experience in peripheral occlusive disease and aortic dissection JOURNAL OF ENDOVASCULAR THERAPY Saket, R. R., Razavi, M. K., Padidar, A., Kee, S. T., Sze, D. Y., Dake, M. D. 2004; 11 (3): 274-280


    To report our experience using a commercially available catheter-based system equipped with an intravascular ultrasound (IVUS) transducer to achieve controlled true lumen re-entry in patients undergoing subintimal angioplasty for chronic total occlusions (CTO) or aortic dissections.During an 8-month period, 10 patients (6 men; mean age 73.4 years) with lower extremity (LE) ischemia from CTOs (n=7) or true lumen collapse from aortic dissections (n=3) were treated. Subintimal access and controlled re-entry of the CTOs were performed with a commercially available 6.2-F dual-lumen catheter, which contained an integrated 64-element phased-array IVUS transducer and a deployable 24-G needle through which a guidewire was passed once the target lumen was reached. The occluded segments were balloon dilated; self-expanding nitinol stents were deployed. In the aortic dissections, fenestrations were performed using the same device, with the IVUS unit acting as the guide. The fenestrations were balloon dilated and stented to support the true lumen.Time to effective re-entry ranged from 6 to 10 minutes (mean 7) in the CTOs; antegrade flow was restored in all 7 CTOs, and the patients were free of ischemic symptoms at up to 8-month follow-up. In the aortic dissection cases, the fenestrations equalized pressures between the lumens and restored flow into the compromised vessels. There were no complications related to the use of this device in any of the 10 patients.Our preliminary results demonstrate the feasibility of using this catheter-based system for subintimal recanalization with controlled re-entry in CTOs and for aortic flap fenestrations in aortic dissections. This approach can improve the technical success rate, reduce the time of the procedure, and minimize potential complications.

    View details for Web of Science ID 000222157100007

    View details for PubMedID 15174902

  • Successful treatment of a Stanford type A dissection by percutaneous placement of a covered stent graft in the ascending aorta JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Ihnken, K., Sze, D., Dake, M. D., Fleischmann, D., van der Starre, P., Robbins, R. 2004; 127 (6): 1808-1810

    View details for DOI 10.1016/j.jteves.2003.12.019

    View details for Web of Science ID 000221895700036

    View details for PubMedID 15173740

  • Atherosclerotic vascular disease conference - Writing group VI: Revascularization CIRCULATION Bettmann, M. A., Dake, M. D., Hopkins, L. N., Katzen, B. T., White, C. J., Eisenhauer, A. C., Pearce, W. H., Rosenfield, K. A., Smalling, R. W., Sos, T. A., Venbrux, A. C. 2004; 109 (21): 2643-2650
  • Aortic intramural haematoma: current therapeutic strategy HEART Dake, M. D. 2004; 90 (4): 375-378

    View details for DOI 10.1136/hrt.2003.027631

    View details for Web of Science ID 000220197700008

    View details for PubMedID 15020506

  • Midterm results of endovascular repair of descending thoracic aortic aneurysms with first-generation stent grafts 29th Annual Meeting of the Western-Thoracic-Surgical-Association Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Sze, D., Razavi, M. K., Dake, M. D. MOSBY-ELSEVIER. 2004: 664–73


    Five years after reporting our initial stent-graft repair of descending thoracic aortic aneurysms experience, we determined the 5- to 10-year results of stent-graft treatment and identified risk factors for adverse late outcomes.Between 1992 and 1997, 103 patients (mean age 69 +/- 12 years) underwent repair using first-generation (custom-fabricated) stent grafts. Sixty-two patients (60%) were unsuitable candidates for conventional open surgical repair ("inoperable"). Follow-up was 100% complete (mean 4.5 +/- 2.5 years; maximum 10 years). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, and/or aortic-related or sudden death).Overall actuarial survival was 82% +/- 4%, 49% +/- 5%, and 27% +/- 6% at 1, 5, and 8 years. Survival in open surgical candidates was 93% +/- 4% and 78% +/- 6% and at 1 and 5 years compared with 74% +/- 6% and 31% +/- 6% in those deemed inoperable (P <.001). Independent risk factors for death were older age (hazard ratio = 1.1; P =.008), previous stroke (hazard ratio = 2.8; P =.003), and being designated an inoperable candidate (hazard ratio = 1.9; P =.04). Actuarial freedom from aortic reintervention and treatment failure at 8 years was 70% +/- 6% and 39% +/- 8%, respectively. Earlier operative year (hazard ratio = 1.2; P =.07), larger distal landing zone diameter (hazard ratio = 1.1; P =.001), and transposition of the left subclavian artery (hazard ratio = 3.3; P =.008) were determinants of treatment failure.Survival after aneurysm repair using crude, first-generation stent grafts was satisfactory in good operative candidates but bleak in the inoperable cohort, raising the question of whether asymptomatic patients should have even been treated. Late aortic complications were detected in many patients, reemphasizing the importance of serial imaging surveillance.

    View details for DOI 10.1016/j.jtcvs.2003.10.047

    View details for Web of Science ID 000220115400013

    View details for PubMedID 15001894

  • Percutaneous bypass: subintimal recanalization of peripheral occlusive disease with IVUS guided luminal re-entry. Techniques in vascular and interventional radiology Saketkhoo, R. R., Razavi, M. K., Padidar, A., Kee, S. T., Sze, D. Y., Dake, M. D. 2004; 7 (1): 23-27


    Angioplasty of chronic total occlusions (CTOs) has lower technical success rates with longer procedure times and poorer outcomes. Subintimal recanalization remains limited by the lack of controlled re-entry into the true lumen of the target vessel. We report our experience using a commercially available catheter-based system equipped with an intravascular ultrasound scanner to achieve controlled true lumen re-entry in patients with peripheral CTOs. In a 4-month period, 6 patients with lower extremity (LE) ischemia from CTOs were treated. Occluded segments were crossed subintimally, and controlled re-entry was secured using the CrossPoint TransAccess catheter. This 6.2 F dual-lumen catheter contains an integrated 64-element phased array intravascular ultrasound scanner enabling targeting of structures. Intravascular ultrasound-guided luminal re-entry was achieved by advancing a 24-gauge needle to a desired length and delivering a 0.014" guide wire into the target lumen. The occluded segments were balloon dilated and stented using self-expanding nitinol stents. Effective luminal re-entry and re-establishment of antegrade flow occurred in all 6 patients. Time to recanalization ranged from 5 to 10 minutes. All patients were free of ischemic symptoms at 1 to 5 month follow-up. There were no procedure-related complications. Our preliminary results demonstrate the feasibility of using this catheter system for subintimal recanalization with controlled re-entry in CTOs. This approach can improve the technical success rate, reduce the time of the procedure, and minimize potential complications.

    View details for PubMedID 15071777

  • Response of balloon-expandable endoprosthetic metallic stents subjected to over-expansion in vitro CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Montague, B. J., Kakimoto, W. M., Arepally, A., Razavi, M., Dake, M. D., Hofmann, L. V. 2004; 27 (2): 158-163


    We attempted to evaluate the in vitro behavior and performance of balloon-expandable endoprosthetic metallic stents subjected to over-expansion (OE). Seventy-two balloon-expandable endoprosthetic stents, representing 22 models from six manufacturers, were overexpanded in vitro. Stents were initially expanded to their maximum manufacturer- recommended diameter and then over-expanded incrementally to their endpoints. Endpoints for OE were either stent disarticulation or an inability to undergo further expansion despite balloon insufflation to maximum burst pressure. Measurements of stent dimensions were recorded at each overexpanded diameter and comparisons were made to manufacturer's specifications. A total of 288 balloon-driven expansions were performed on 72 stents. Sixteen stents were expanded to large diameters (> or = 16 mm), 20 stents underwent OE of 50% or greater. One model tended to disarticulate after OE greater than 50%. There were five models that had a tendency to disarticulate after minimal OE. Five models were resistant to OE (25% or less OE) but did not disarticulate. Nearly all stents showed some degree of foreshortening with OE, while 36 stents underwent foreshortening of 30% or more. Models that are not recommended for OE include Intrastent, Intrastent DoubleStrut, NIR Royale and Omniflex. Good candidates for OE include Intrastent DoubleStrut LD, Palmaz large, Medtronic Extra Support Biliary Plus and Medtronic Flexible Biliary. Palmaz XL remains the only model available for expansion from 20 to 28 mm in diameter. For the remaining stents, OE is possible, however, caution should be used.

    View details for DOI 10.1007/s00270-003-4600-y

    View details for Web of Science ID 000221104200010

    View details for PubMedID 15259812

  • Chronic traumatic aneurysms of the descending thoracic aorta: mid-term results of endovascular repair using first and second-generation stent-grafts EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY Demers, P., Miller, C., Mitchell, R. S., Kee, S. T., Chagonjian, R. N., Dake, M. D. 2004; 25 (3): 394-400


    Endovascular stent-graft repair holds promise for treating traumatic injuries of the descending thoracic aorta. The durability of this approach, however, remains unknown. The objective is to evaluate the mid-term results of stent-graft repair of chronic traumatic aneurysms of the descending thoracic aorta.Between 1993 and 2000, endovascular repair of the descending thoracic aorta with first (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 15 patients (mean age 54+/-13 years) at an average of 18+/-14 years after the injury. Because of comorbidities, 4 patients (27%) were judged not to be reasonable surgical candidates for conventional open surgical approach. Follow-up was 100% complete and averaged 55+/-29 months.Stent-graft deployment was successful in all without need for surgical conversion. One patient died early postoperatively. No neurologic complications occurred. Two patients had a primary endoleak, one of them was successfully treated before discharge. Actuarial survival estimates at 1 and 6 years were 93+/-6% and 85+/-10%. Actuarial freedom from reintervention on the descending thoracic aorta was 93+/-6% and 70+/-15% at 1 and 6 years, respectively. Actuarial freedom from treatment failure (a conservative, all-encompassing performance indicator including endoleak, device mechanical fault, reintervention, late aortic-related death, or sudden, unexplained late death) at 1 and 6 years was 87+/-8% and 51+/-15%.Stent-grafting is safe in selected patients with chronic traumatic aneurysms and associated with satisfactory-but not optimal-mid-term durability. Serial follow-up surveillance imaging is mandatory to detect late stent-graft complications. Younger, good risk patients should be offered conventional open operation, reserving stent-grafting for those who are at prohibitive operative risk or who have limited life expectancy.

    View details for DOI 10.1016/j.ejcts.2003.11.035

    View details for Web of Science ID 000220286800015

    View details for PubMedID 15019666

  • In-stent restenosis limitation with stent-based controlled-release nitric oxide: Initial results in rabbits RADIOLOGY Do, Y. S., Kao, E. Y., Ganaha, F., Minamiguchi, H., Sugimoto, K., Lee, J., Elkins, C. J., Amabile, P. G., Kuo, M. D., Wang, D. S., Waugh, J. M., Dake, M. D. 2004; 230 (2): 377-382


    To evaluate effect of controlled stent-based release of an NO donor to limit in-stent restenosis in rabbits.Bioerodable microspheres containing NO donor or biodegradable polymer (polylactide-co-glycolide-polyethylene glycol) were prepared and loaded in channeled stents. Daily concentrations of NO release from NO-containing microspheres were assayed in vitro. NO- and polymer-containing (control) microsphere-loaded stents were deployed in aortas of New Zealand white rabbits (n = 8). Aortas with stents were harvested at 7 (n = 5) and 28 days (n = 3) and evaluated for cyclic guanosine monophosphate (cGMP) levels (7 days), number of proliferating cell nuclear antigen-positive cells (7 days), and intima-to-media ratio (7 and 28 days), with statistical significance evaluated by using one-way analysis of variance.NO-containing microspheres released NO with an initial bolus in the 1st week, followed by sustained release for the remaining 3 weeks. Significant increase in cGMP levels and decrease in proliferating cell nuclear antigen-positive cells were found at 7 days for the NO-treated group relative to controls (P <.05). Intima-to-media ratio in the NO-treated group was reduced by 46% and 32% relative to controls at 7 and 28 days, respectively (mean, 0.14 +/- 0.01 [standard error] vs 0.26 +/- 0.02 at 7 days, P <.01; 1.34 +/- 0.05 vs 1.98 +/- 0.08 at 28 days, P <.01).Stent-based controlled release of NO donor significantly reduces in-stent restenosis and is associated with increase in vascular cGMP and suppression of proliferation.

    View details for DOI 10.1148/radiol.2302020417

    View details for Web of Science ID 000188463700012

    View details for PubMedID 14699187

  • Stent-graft repair of penetrating atherosclerotic ulcers in the descending thoracic aorta: Mid-term results ANNALS OF THORACIC SURGERY Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Chagonjian, L., Dake, M. D. 2004; 77 (1): 81-86


    Localized aortic pathoanatomic abnormalities are good targets for endovascular stent-grafting but only short-term results have been reported. Our objective was to determine the effectiveness of endovascular stent-graft treatment of patients with descending thoracic atherosclerotic penetrating atherosclerotic ulcers (PAU) and to identify risk factors for treatment failure.Between 1993 and 2000 endovascular repair of PAU with first-generation (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 26 patients (mean age, 70 years), 6 (23%) of whom had rupture. Fourteen patients (54%) were not candidates for open surgical repair. Follow-up was 100% complete (average, 51 months; maximum, 114 months). Outcome variables considered in the multivariable analysis included death and treatment failure (composite end-point comprising early death, endoleak, stent-graft mechanical fault, late aortic event, reintervention, and aortic-related or sudden death).Three patients (12% +/- 7% [+/-70% confidence limits]) died within 30 days and 2 had an early type I endoleak. Primary success rate was 92%. Actuarial survival estimates at 1, 3, and 5 years were 85% +/- 8%, 76% +/- 8% and 70% +/- 10% respectively and actuarial freedom from treatment failure was 81% +/- 8%, 71% +/- 9% and 65% +/- 10%. Multivariable analyses identified previous cerebrovascular accident (hazard ratio [HR] 17.1, p = 0.02) and female sex (HR 7.4, p = 0.08) as independent risk factors for death. For treatment failure the predictors were increasing aortic diameter (HR 1.1 [per mm above the mean value], p = 0.01) and female sex (HR 5.5, p = 0.09).Endovascular stent-graft repair is effective but not curative treatment for selected, high surgical risk, elderly patients with a descending aortic PAU over the medium term. Assiduous serial follow-up imaging after stent-grafting is mandatory to detect late complications especially in those with a large aorta.

    View details for DOI 10.1016/S0003-4975(03)00816-6

    View details for Web of Science ID 000187735800017

    View details for PubMedID 14726040

  • Direct medical costs attributable to acute myocardial infarction and ischemic stroke in cohorts with atherosclerotic conditions CEREBROVASCULAR DISEASES Sloss, E. M., Wickstrom, S. L., McCaffrey, D. F., Garber, S., Rector, T. S., Levin, R. A., Guzy, P. M., Gorelick, P. B., Dake, M. D., Vickrey, B. G. 2004; 18 (1): 8-15


    The cost of acute ischemic events in persons with established atherosclerotic conditions is unknown.The direct medical costs attributable to secondary acute myocardial infarction (AMI) or ischemic stroke among persons with established atherosclerotic conditions were estimated from 1995-1998 data on 1,143 patients enrolled in US managed care plans.The average 180-day costs attributable to secondary AMI or stroke were estimated as USD 19,056 in the AMI cohort having a private insurance (commercial; n = 344), USD 16,845 in the AMI cohort having government insurance (Medicare, age >/=65 years; n = 200), USD 10,267 for stroke commercial (n = 108), USD 16,280 for stroke Medicare (n = 113), USD 15,224 for peripheral arterial disease commercial (n = 170), and USD 15,182 for peripheral arterial disease Medicare (n = 208).These estimates can be used to study the cost-effectiveness of interventions proven to reduce these secondary events.

    View details for DOI 10.1159/000078602

    View details for Web of Science ID 000222098300003

    View details for PubMedID 15159615

  • CT-guided transthoracic needle aspiration biopsy of pulmonary nodules: Needle size and pneumothorax rate RADIOLOGY Geraghty, P. R., Kee, S. T., McFarlane, G., Razavi, M. K., Sze, D. Y., Dake, M. D. 2003; 229 (2): 475-481


    To evaluate the effect of coaxial needle size on pneumothorax rate and the diagnostic accuracy of computed tomography (CT)-guided transthoracic needle aspiration biopsy (TNAB) of pulmonary nodules.Retrospective review of 846 consecutive CT-guided TNAB procedures was performed. A coaxial approach was implemented in all patients by using an 18- or 19-gauge outer stabilizing needle through which a smaller aspiration needle or automated biopsy gun was inserted for tissue sampling. Univariate and multivariate regression analyses were used to analyze coaxial needle size, age, sex, smoking history, lesion size, use of an automated core biopsy gun, number of needle passes, and frequency of chest tube placement. Sensitivity, specificity, and diagnostic accuracy were calculated for 676 patients with at least 18 months of clinical follow-up.Pneumothorax occurred in 226 of 846 patients. Coaxial needle size and patient age had a significant effect on pneumothorax rate. Pneumothorax occurred in 124 (38%) of 324 patients who underwent procedures with 18-gauge needles and in 121 (23%) of 522 patients who underwent procedures with 19-gauge needles (P <.001). The overall diagnostic accuracy was 96% for procedures performed with 18-gauge needles and 92% for procedures performed with 19-gauge needles, with a sensitivity of 95% and 89% and a specificity of 100% and 99%, respectively. Pneumothorax occurred in 153 patients older than 60 years, in 99 patients 60 years and younger (P <.02), in 90 patients older than 70 years, and in 162 patients younger than 70 years (P <.01). The relationship between pneumothorax rate and age as a continuous distribution was not significant (P <.07), nor were the 50- or 75-year age cutoffs (P <.06 and P <.9, respectively).Use of a smaller coaxial stabilizing needle produces a substantially decreased risk of pneumothorax with comparable diagnostic accuracy, sensitivity, and specificity for histopathologic diagnosis of pulmonary nodules.

    View details for Web of Science ID 000186169700027

    View details for PubMedID 14595149

  • Guidelines for development and use of transluminally placed endovascular prosthetic grafts in the arterial system. Journal of vascular and interventional radiology Veith, F. J., Abbott, W. M., Yao, J. S., Goldstone, J., White, R. A., Abel, D., Dake, M. D., Ernst, C. B., Fogarty, T. J., Johnston, K. W., Moore, W. S., van Breda, A., Sopko, G., Didisheim, P., Rutherford, R. B., Katzen, B. T., Miller, D. C. 2003; 14 (9): S405-17

    View details for PubMedID 14514856

  • The "Y" stent: A technique using nitinol stents to treat bifurcations JOURNAL OF ENDOVASCULAR THERAPY Sze, D. Y., Razavi, M. K., Mitri, R. K., Regala, A. C., Dake, M. D. 2003; 10 (4): 780-787


    To investigate a new method of stent deployment using commercially available self-expanding stents to treat bifurcation lesions, providing complete lesion coverage without obstructing branches.After preliminary in vitro and clinical testing with biliary obstructions, 11 vascular obstructive lesions in 10 patients (7 men; mean age 63 years, range 32-81) were treated by percutaneous Y-shaped stenting. Five patients had iliac arterial stenoses involving the iliac bifurcation; the other 5 patients had 6 central venous obstructions involving branch points. Bifurcated stents were constructed in situ by deploying a nitinol stent extending into one branch and selective balloon fracturing of struts to create a fenestration. A second stent was deployed through the hole, followed by symmetrical fracturing of struts in the second stent to form a Y-shaped configuration.All deployments were technically successful and resulted in complete coverage of the bifurcation lesions. Protrusion of fractured stent material into flow lumens was minor as determined by angiography, intravascular ultrasound, and passage of balloons, but it required the stents to be oversized. The lengths and luminal diameters were tailored for each arm of the Y-shaped stents.In situ creation of a Y-shaped stent using 2 self-expanding nitinol stents is a feasible option with potential advantages in the treatment of obstructive lesions involving a bifurcation.

    View details for Web of Science ID 000186217600015

    View details for PubMedID 14533963

  • Type A aortic dissection developing during endovascular repair of an acute type B dissection JOURNAL OF ENDOVASCULAR THERAPY Fanelli, F., Salvatori, F. M., Marcelli, G., Bezzi, M., Totaro, M., Vagnarelli, S., Dake, M. D., Rossi, P., Passariello, R. 2003; 10 (2): 254-259


    To describe an extension of type B dissection into type A during endoluminal treatment of acute type B dissection.A 57-year-old man with acute type B dissection underwent endovascular repair using 2 Excluder stent-grafts. Before releasing the second stent-graft, the patient complained of mild central chest pain, headache, and visual flashes, but no hemodynamic changes were noticed. An angiogram, performed soon afterwards, showed a retrograde extension of the dissection through the aortic arch involving both the left carotid artery and the ascending aorta. The procedure was completed, and the patient was transported to the operating room where the proximal ascending aorta was replaced. Spiral computed tomographic angiography performed 2 weeks after the procedure showed complete exclusion of the primary entry tear. At 6-month follow-up, the patient was asymptomatic; the left carotid artery dissection had disappeared.Endovascular repair of acute type B dissection is technically feasible, but longer experience will help prevent technical complications.

    View details for Web of Science ID 000184764900014

    View details for PubMedID 12877608

  • Endovascular stent-graft repair of descending thoracic aortic penetrating atherosclerotic ulcers: Mid-term results 52nd Annual Scientific Session of the American-College-of-Cardiology Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Chagonjian, L., Dake, M. D. ELSEVIER SCIENCE INC. 2003: 236A–236A
  • The safety, efficacy, and pharmacoeconomics of low-dose alteplase compared with urokinase for catheter-directed thrombolysis of arterial and venous occlusions JOURNAL OF VASCULAR SURGERY Sugimoto, K., Hofmann, L. V., Razavi, M. K., Kee, S. T., Sze, D. Y., Dake, M. D., Semba, C. P. 2003; 37 (3): 512-517


    The purpose of this study was to compare the efficacy, complications, and costs associated with low-dose (<2 mg/h) alteplase (tissue plasminogen activator [t-PA]) versus urokinase for the catheter-directed treatment of acute peripheral arterial occlusive disease (PAO) and deep vein thrombosis (DVT).A retrospective review was performed during sequential time periods on two groups with involved extremities treated with either t-PA with subtherapeutic heparin (TPA group) or urokinase with full heparin (UK group) at a single center. Treatment group characteristics, success rates, complications, dosages, infusion time, and costs were compared.Eighty-nine patients with 93 involved limbs underwent treatment (54 with DVT, 39 with PAO). The treatment groups were statistically identical (TPA: 45 limbs; 24 with DVT, 53.3%; 21 with PAO, 46.7%; UK: 48 limbs; 30 with DVT, 62.5%; 18 with PAO, 37.5%). The overall average hourly infused dose, total dose, infusion time, success rates, and cost of thrombolytic agent were as follows (+/- standard deviation): TPA, 0.86 +/- 0.50 mg/h, 21.2 +/- 15.1 mg, 24.6 +/- 11.2 hours, 89.4%, $466 +/- $331; and UK, 13.5 +/- 5.6 (10(4)) U/h, 4.485 +/- 2.394 million U, 33.3 +/- 13.3 hours, 85.7%, $6871 +/- $3667, respectively. Major and minor complication rates were: TPA, 2.2% and 8.9%; and UK, 2.1% and 10.4%, respectively. No statistical differences in success rates or complications were observed; however, t-PA was significantly (P <.05) less expensive and faster than urokinase.Low-dose t-PA combined with subtherapeutic heparin is equally efficacious and safe compared with urokinase. Infusions with t-PA were significantly shorter and less expensive than those with urokinase.

    View details for DOI 10.1067/mva.2002.41

    View details for Web of Science ID 000181364400005

    View details for PubMedID 12618684

  • Images in cardiovascular medicine. Value of three-dimensional reconstructions in evaluating thoracic aortic aneurysms. Circulation Luccichenti, G., Cademartiri, F., Dake, M. D., Larini, P., Pavone, P. 2003; 107 (5): E34-5

    View details for PubMedID 12578887

  • Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? 27th Annual Meeting of the Western-Thoracic-Surgical-Association Umana, J. P., Lai, D. T., Mitchell, R. S., Moore, K. A., Rodriguez, F., Robbins, R. C., Oyer, P. E., Dake, M. D., Shumway, N. E., Reitz, B. A., Miller, D. C. MOSBY-ELSEVIER. 2002: 896–910


    The optimal treatment of patients with acute type B dissections continues to be debated.A 36-year clinical experience of medical and surgical treatments in 189 patients was retrospectively analyzed (multivariable Cox proportional hazards model) with respect to three outcome end points: all deaths, freedom from reoperation, and freedom from late aortic complications or death. Propensity score analysis identified 2 quintiles (quintiles I and II, consisting of 142 comparable patients) for further comparison of the effects of surgical versus medical treatment.Shock (hazard ratio 14.5, 95% confidence interval 4.7-44.5, P <.001) and visceral ischemia (hazard ratio 10.9, 95% confidence interval 3.9-30.3, P <.001) largely predominated as determinants of death, along with 6 other risk factors (arch involvement, rupture, stroke, previous sternotomy, and coronary or lung disease), which roughly doubled the hazard of death. Female sex was a significant but weaker predictor of death. Renal dysfunction, year of presentation, age, and mode of therapy (medical vs surgical) had no important bearing on overall survival. The actuarial survival estimates for all patients were 71%, 60%, 35%, and 17% at 1, 5, 10, and 15 years, respectively, and were similar for the medical and surgical patients. Reoperation and late aortic complications were predicted by the presence of Marfan syndrome. For the propensity-matched patients in quintiles I and II, survival, freedom from reoperation, and freedom from aortic complications were almost identical in the medically treated and surgical subsets.The prognosis for patients with acute type B aortic dissection is bleak and determined primarily by dissection-related and patient-specific risk factors, which do not appear to be readily modifiable.

    View details for DOI 10.1067/mtc.2002.123131

    View details for Web of Science ID 000179012300006

    View details for PubMedID 12407372

  • Initial clinical results of tenecteplase (TNK) in catheter-directed thrombolytic therapy JOURNAL OF ENDOVASCULAR THERAPY Razavi, M. K., Wong, H., Kee, S. T., Sze, D. Y., Semba, C. P., Dake, M. D. 2002; 9 (5): 593-598


    To investigate the safety and immediate efficacy of 2 different doses of tenecteplase (TNK) in peripheral catheter-directed thrombolytic therapy of arterial occlusions and deep vein thrombosis (DVT).Over a 20-month period, 63 nonconsecutive patients underwent catheter-directed thrombolytic therapy with either 0.25 mg/h or 0.50 mg/h of TNK in a nonrandomized, open-label study. Of these, 55 patients (60 limbs) were treated for DVT (36 limbs in 16 men and 15 women; mean age 41 years, range 21-73) or peripheral arterial occlusions (24 limbs in 16 men and 8 women; mean age 63 years, range 32-91). The primary endpoints were major bleeding complications and angiographic reduction in clot burden.The mean duration of infusion was 18 +/- 4 hours in patients with arterial occlusions and 30 +/- 13 in those with DVT. Twenty-one (87.5%) patients with occlusive disease had marked or complete lysis of clot. Thirty (83.3%) limbs with DVT had either marked or complete resolution of thrombus. There were 4 (7.3%) episodes of minor bleeding with 1 (1.8%) major hemorrhagic event. Fibrinogen levels dropped by an average of 23%.Preliminary evidence suggests that TNK doses of 0.25 mg/h to 0.50 mg/h appear to be safe and effective. The potential benefits of TNK therapy warrant further investigation.

    View details for Web of Science ID 000179638100009

    View details for PubMedID 12431142

  • Angiographic classification of ovarian artery-to-uterine artery anastomoses: Initial observations in uterine fibroid embolization RADIOLOGY Razavi, M. K., Wolanske, K. A., Hwang, G. L., Sze, D. Y., Kee, S. T., Dake, M. D. 2002; 224 (3): 707-712


    To prospectively study and classify the anastomoses between the ovarian and uterine arteries in women undergoing uterine fibroid embolization, and to compare the presence of such with procedural failures and premature menopause.Angiographic ovarian artery-to-uterine artery anastomoses were studied in 76 consecutive patients undergoing uterine fibroid embolization. Mean patient age was 44.7 years (range, 29-56 years). Clinical follow-up consisted of a standard questionnaire. Procedural failure and complications were compared with the presence of various types of ovarian artery-to-uterine artery connections.Three types of anastomoses were identified. In type I (33 [21.7%] of 152 arteries), flow from the ovarian artery to the uterus was through anastomoses with the main uterine artery. In type II (six arteries [3.9%]), the ovarian artery supplied the fibroids directly. In type III (10 arteries [6.6%]), the major blood supply to the ovary was from the uterine artery. Seven patients (9%) were considered to have clinical failure, with three of the six women with type II anastomoses being in this group. Three of the five women who experienced menopause after fibroid embolization had bilateral ovarian artery-to-uterine artery anastomoses that were classified as high risk.Delineation of ovarian artery-to-uterine artery anastomosis is of practical relevance in avoiding nontarget ovarian embolization, in identification of those who would be at risk of uterine artery embolization or ovarian failure, and in those in whom the ovarian artery can be embolized safely.

    View details for DOI 10.1148/radiol.2243011513

    View details for Web of Science ID 000177621700013

    View details for PubMedID 12202703

  • Prognosis of aortic intramural hematoma with and without penetrating atherosclerotic ulcer - A clinical and radiological analysis CIRCULATION Ganaha, F., Miller, C., Sugimoto, K., Do, Y. S., Minamiguchi, H., Saito, H., Mitchell, R. S., Dake, M. D. 2002; 106 (3): 342-348


    Advances in imaging techniques have increased the recognition of aortic intramural hematomas (IMHs) and penetrating atherosclerotic ulcers (PAUs); however, distinction between IMH and PAU remains unclear. We intended to clarify differences between IMH coexisting with PAU and IMH not associated with PAU by comparisons of clinical features, imaging findings, and patient outcome to derive the optimal therapeutic approach.We performed a retrospective analysis of 65 symptomatic patients with aortic IMH. There were 34 patients with IMH associated with PAU (group 1) and 31 patients with IMH unaccompanied by PAU (group 2). Involvement of the ascending aorta (type A) was more frequent in group 2 (8 of 31, 26%), whereas most of the patients in group 1 had exclusive involvement of the descending aorta (type B) (31of 34, 91%). Patients were subdivided into 2 categories, those with clinical progression and those with stable disease. Forty-eight percent of patients in group 1 and 8% in group 2 were in the progressive category (P=0.002). Clinical and radiological findings were compared between those group 1 patients who had a progressive disease course (n=12) and those who were stable (n=13). Sustained or recurrent pain (P<0.0001), increasing pleural effusion (P=0.0003), and both the maximum diameter (P=0.004) and maximum depth (P=0.003) of the PAU were reliable predictors of disease progression.This study suggests a difference in disease behavior that argues for the prognostic importance of making a clear distinction between IMH caused by PAU and IMH not associated with PAU. IMH with PAU was significantly associated with a progressive disease course, whereas IMH without PAU typically had a stable course, especially when limited to the descending thoracic aorta.

    View details for DOI 10.1161/01.CIR.0000022164.26075.5A

    View details for Web of Science ID 000176944300015

    View details for PubMedID 12119251

  • In vivo vascular engineering of vein grafts: Directed migration of smooth muscle cells by perivascular release of elastase limits neointimal proliferation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Amabile, P. G., Wong, H., Uy, M., Boroumand, S., Elkins, C. J., Yuksel, E., Waugh, J. M., Dake, M. D. 2002; 13 (7): 709-715


    Saphenous vein bypass grafting for coronary revascularization procedures remains limited by accelerated neointima formation. It was hypothesized that creation of a modified chemotactic gradient in vivo could guide migration of smooth muscle cells (SMCs) peripherally instead of in a luminal direction and reduce intimal hyperplasia during vein graft arterialization.Surgical bypass vein grafting to femoral arteries was performed in adult male New Zealand White rabbits (n = 8 per treatment group; five for 7 d and three for 28 d). Controlled-release microspheres delivering elastase or buffered polymer only were administered perivascularly at the vein graft site. At 7 days, five vein grafts per group were harvested and cross-sections were immunostained with anti-proliferating cell nuclear antigen (PCNA) to determine the number and distribution of proliferating SMCs. At 28 days, three vein grafts per group were harvested and intima-to-media (I/M) ratios were calculated after staining with Verhoeff von Gieson-Masson trichrome stain.Significant early outward-directed elastin degradation resulted from elastase treatment. Concurrently, proliferating SMCs migrated peripherally. PCNA(+) cells in the outer half of the wall increased 2.37 fold compared to procedural controls (P <.0001). Directional shifts in SMC migration underlie these results because overall SMC proliferation was not significantly different. At 28 days after vein graft surgery, a 38% reduction (P =.0008) in neointima was observed relative to procedural controls.Directional guidance of SMC responses through perivascular elastase release achieves favorable vein graft remodeling characteristics, including limited neointima development. This represents practical evidence that SMC migration can be directionally guided in vivo in a vein graft model and that plaque progression can be prevented by redistributing elastin without decreasing functional vein graft wall stability.

    View details for Web of Science ID 000177228700008

    View details for PubMedID 12119330

  • Inhibition of vascular endothelial growth factor-mediated neointima progression with angiostatin or paclitaxel JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Celletti, F. L., Waugh, J. M., Amabile, P. G., Kao, E. Y., Boroumand, S., Dake, M. D. 2002; 13 (7): 703-707


    Therapeutic angiogenesis represents a new paradigm for treatment of ischemic vascular syndromes. However, vascular endothelial growth factor (VEGF) enhances the rate and degree of plaque formation. This study evaluates the potential to block these effects nonspecifically with paclitaxel or specifically with angiostatin.Recombinant human VEGF(165) (rhVEGF) was administrated intramuscularly (2-microg/kg single injection) in combination with adventitial delivery of paclitaxel, angiostatin, or vehicle alone at the site of femoral arterial balloon overdilation injury in New Zealand White rabbits (n = 5 per treatment). Five additional animals with no rhVEGF and no adventitial delivery served as procedural controls. All rabbits were fed according to a 0.25% cholesterol diet beginning 28 days before angioplasty. Treated arteries were harvested after 7 days and evaluated to determine intima-to-media (I/M) ratios, macrophage infiltrate, and endothelial cell density.On histologic analysis, the rhVEGF/gel control group exhibited a mean I/M ratio of 0.337 +/- 0.028, a 77% increase over procedural controls, which exhibited a mean I/M of 0.190 +/- 0.010. rhVEGF/paclitaxel reduced I/M ratios to 0.151 +/- 0.007. In contrast, specific antiangiogenic therapy (rhVEGF/angiostatin) reduced I/M ratios to 0.032 +/- 0.003, a 91% decrease relative to rhVEGF/gel and an 83% decrease relative to procedural controls (P =.001 for each comparison). Local macrophages and endothelial cells also decreased with treatment.This study shows that paclitaxel and angiostatin each afford local protection against rhVEGF-mediated increases in neointima. Angiostatin further prevents progression of underlying neointima. These local therapies may allow broader use of therapeutic angiogenesis while avoiding and treating potentially undesirable effects.

    View details for Web of Science ID 000177228700007

    View details for PubMedID 12119329

  • Development of a platform to evaluate and limit in-stent restenosis TISSUE ENGINEERING Elkins, C. J., Waugh, J. M., Amabile, P. G., Minamiguchi, H., Sugimoto, K., Ganaha, F., Razavi, M. K., Dake, M. D. 2002; 8 (3): 395-407


    The objective of this work was to develop a platform to evaluate and deliver putative therapeutic agents for in-stent restenosis. Arterial stenting is applied in more than 60% of balloon angioplasties for treating cardiovascular disease. However, stented arteries encounter accelerated rates of restenosis. No prior platform has allowed evaluation or local management of in-stent restenosis without perturbing the very system being examined. A stainless steel, balloon-expandable stent was modified to serve as an ablumenal drug delivery platform. Several combinations of bioerodible polymer microspheres and gels were evaluated for channel retention under in vitro flow and in vivo conditions. A stent-anchored hybrid system prevented material embolization under all conditions. Unlike prior platforms, these stents do not alter local inflammation or in-stent plaque formation relative to conventional Palmaz-Schatz stents after in vivo deployment. The system also proved sensitive enough to detect plaque reduction with an antirestenotic agent. We conclude that a platform to evaluate and deliver therapeutic agents for in-stent restenosis has been achieved.

    View details for Web of Science ID 000176677800005

    View details for PubMedID 12167226

  • Occurrence of secondary ischemic events among persons with atherosclerotic vascular disease STROKE Vickrey, B. G., Rector, T. S., Wickstrom, S. L., Guzy, P. M., Sloss, E. M., Gorelick, P. B., Garber, S., McCaffrey, D. F., Dake, M. D., Levin, R. A. 2002; 33 (4): 901-906


    Few data exist for large managed care populations on the occurrence of subsequent acute ischemic events in persons with established atherosclerotic vascular disease. We estimated the occurrence of secondary stroke, acute myocardial infarction (AMI), and vascular deaths among 2 large, managed care samples.With the use of International Classification of Diseases, Ninth Revision, Clinical Modification codes, patients aged > or =40 years and with stroke, AMI, or peripheral arterial disease (PAD) were identified from administrative data of UnitedHealthcare plans during 1995-1998. Stroke, AMI, and PAD cohorts were identified within a commercial insurance sample and a Medicare sample. Cumulative occurrences of subsequent stroke, AMI, or vascular death were estimated by survival analysis.In the stroke commercial cohort (n=1631; mean age, 62.1 years), cumulative occurrence of subsequent events was 4.2%, 6.5%, 9.8%, and 11.8% at 0.5, 1, 2, and 3 years, respectively; cumulative secondary event occurrence in the AMI commercial cohort (n=6458; mean age, 56.0 years) was 3.5%, 4.8%, 7.3%, and 8.5% and in the PAD commercial cohort (n=5813; mean age, 59.2 years) was 1.5%, 2.8%, 4.8%, and 6.5%, respectively. Cumulative secondary event occurrences were even higher in stroke (n=1518; mean age, 79.5 years), AMI (n=2197; mean age, 76.2 years), and PAD (n=5033; mean age, 76.6 years) cohorts of the Medicare sample: 18.1%, 17.0%, and 8.7%, respectively, at 3 years. More than 75% of each stroke cohort's secondary events were strokes; more than 75% of each AMI cohort's secondary events were AMIs. Of the PAD cohorts' secondary events, 27% to 39% were strokes, 48% to 57% were AMIs, and 13% to 16% were vascular deaths.Among these managed care enrollees with existing atherosclerotic vascular disease, subsequent ischemic events represent a significant symptomatic disease burden. Given these findings, it is very important to determine whether secondary prevention strategies are being effectively used to manage patients with diagnosed atherosclerosis.

    View details for Web of Science ID 000174857400004

    View details for PubMedID 11935034

  • In vivo vascular engineering: Directed migration of smooth muscle cells to limit neointima TISSUE ENGINEERING Wong, A. H., Waugh, J. M., Amabile, P. G., Yuksel, E., Dake, M. D. 2002; 8 (2): 189-199


    Pathologic neointima formation requires directional smooth muscle cell (SMC) migration from media to intima. The very direction of SMC migration thus becomes a potential therapeutic target. Here, we hypothesize that proliferating SMC after injury can be redirected using engineered chemotactic gradients of elastin degradation to limit late pathologic neointima formation. Buffered bioerodible polymeric microspheres (MS) were constructed to provide 4-week sustained release of elastase, heat-killed elastase, or polymer only. In vitro elastase function and timecourse of release at 37 degrees C, physiologic pH, and shear was determined. Curves revealed an initial bolus followed by sustained linear release for elastase MS, while controls exhibited baseline hydrolysis of substrate. We then employ controlled perivascular release of elastase after angioplasty to engineer modified in vivo gradients of elastin degradation in rabbit femoral arteries. NZW rabbits (n = 8 each) underwent balloon angioplasty of the common femoral artery followed by perivascular distribution of MS. Significant early perivascular elastin degradation resulted. Concurrently, proliferating SMC were guided peripherally (further from lumen) with treatment without significant changes in total proliferation or inflammation. At 28 days, treatment significantly reduces neointima by 42% relative to controls. These results confirm that directionally guiding SMC responses after injury achieves favorable arterial remodeling and limits development of pathologic neointima. Thus, a potential class of therapeutics and the paradigm of in vivo vascular engineering emerge from this work.

    View details for Web of Science ID 000175443200003

    View details for PubMedID 12031109

  • Therapeutic elastase inhibition by alpha-1-antitrypsin gene transfer limits neointima formation in normal rabbits JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Waugh, J. M., Li-Hawkins, J., Yuksel, E., Cifra, P. N., Amabile, P. G., Hilfiker, P. R., Geske, R. S., Kuo, M. D., Thomas, J. W., Dake, M. D., Woo, S. L. 2001; 12 (10): 1203-1209


    Alpha-1-antitrypsin (AAT) is the major circulating elastase inhibitor. Deficiency of elastase inhibition leads to emphysema and vascular abnormalities including accelerated neointima. Because recent evidence suggests that tissue AAT levels determine inhibitory function, the authors hypothesize that local tissue-based expression of AAT limits elastase activity sufficiently to guide arterial response to injury.Rabbit common femoral arteries were injured by mechanical overdilation and treated with buffer, viral control, or an adenovirus expressing AAT (Ad/AAT). After 3 and 28 days, intima-to-media (I/M) ratios were evaluated. Additionally, early changes in elastase inhibition potential (3 d), extracellular elastin and collagen content (3 d), and local macrophage and neutrophil infiltration (7 d) were determined.Ad/AAT significantly decreased neointima formation after mechanical dilation injury after 28 days: buffer controls exhibited mean I/M ratios of 0.76 +/- 0.06, whereas viral controls reached 0.77 +/- 0.09; in contrast, Ad/AAT reduced I/M ratios to 0.44 +/- 0.06. Both early elastin and collagen content were preserved in the Ad/AAT group relative to controls. The Ad/AAT group also reversed the local inflammation that characterized viral controls.This strategy demonstrates that local increases in elastase inhibition potential promote a neointima-resistant small-caliber artery, which may offer new promise in management of patients undergoing angioplasty.

    View details for Web of Science ID 000171634000010

    View details for PubMedID 11585887

  • Endovascular stent-graft management of thoracic aortic diseases EUROPEAN JOURNAL OF RADIOLOGY Dake, M. D. 2001; 39 (1): 42-49


    The traditional standard therapy for descending thoracic aortic aneurysm (TAA) is open operative repair with graft replacement of the diseased aortic segment. Despite important advances in surgical techniques, anesthetic management, and post-operative care over the last 30 years, the mortality and morbidity of surgery remains considerable, especially in patients at high risk for thoracotomy because of coexisting severe cardiopulmonary abnormalities or other medical diseases. The advent of endovascular stent-graft technology provides an alternative to open surgery for selected patients with TAA. The initial experience suggests that stent-graft therapy potentially may reduce the operative risk, hospital stay and procedural expenses of TAA repair. These potential benefits are especially attractive for patients at high risk for open TAA repair. Current results of endovascular TAA therapy document operative mortalities of between 0 and 4%, aneurysm thrombosis in 90 and 100% of cases, and paraplegia as a complication in 0 and 1.6% of patients. The early success of stent-graft repair of TAA has fostered the application of these devices for the management of a wide variety of thoracic aortic pathologies, including acute and chronic dissection, intramural hematoma, penetrating ulcer, traumatic injuries, and other diseases. The results of prospective controlled trials that compare the outcomes of stent-graft therapy with those of surgical treatment in patients with specific types of aortic disease are anxiously awaited before recommendations regarding the general use of these new devices can be made with confidence.

    View details for Web of Science ID 000170023800006

    View details for PubMedID 11439230

  • Portal-systemic myelopathy after transjugular intrahepatic portosystemic shunt creation: Report of four cases JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, M. Q., Dake, M. D., Cui, Z. P., Wang, Z. Q., Gao, Y. A. 2001; 12 (7): 879-881


    The authors attempted to describe the clinical manifestations of portal-systemic myelopathy (PSM) after transjugular intrahepatic portosystemic shunt (TIPS) creation. PSM was developed in four of 212 (1.89%) patients who underwent TIPS procedures in our hospital. Three men and one woman, ranging in age from 41 to 56 years, with a history of posthepatitis cirrhosis and recurrent bleeding from gastroesophageal varices had intrahepatic shunts created with 10-mm-diameter Wallstents. Shunt patency was confirmed by color Doppler ultrasonography (US) in each patient after TIPS creation. Progressive spastic paraparesis involving the lower extremities occurred between 5 weeks and 5 months after TIPS creation in the four patients. Neurologic examination showed evidence of spasticity in all cases, with ankle clonus, extensor plantar responses, and lower extremity hyperreflexia. All sensory modalities remained intact. Cytologic examination of cerebrospinal fluid from each patient was normal. There was no evidence of spinal cord compression on the imaging studies. PSM is a rare syndrome that includes spastic paraparesis with intact sensation. Initially noted in patients who have undergone surgical placement of a portacaval shunt, it also may occur after TIPS creation.

    View details for Web of Science ID 000169706900013

    View details for PubMedID 11435545

  • Effect of human recombinant vascular endothelial growth factor(165) on progression of atherosclerotic plaque JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Celletti, F. L., Hilfiker, P. R., Ghafouri, P., Dake, M. D. 2001; 37 (8): 2126-2130


    This study was designed to evaluate the impact of recombinant human vascular endothelial growth factor165 (rhVEGF) on atherosclerotic plaque progression.Therapeutic angiogenesis represents a promising treatment for ischemic diseases. However, angiogenesis may impact atherosclerosis.Albumin or rhVEGF was administered by a single intramuscular injection (2 microg/kg body weight) to New Zealand White rabbits fed with a 0.25% cholesterol diet beginning three weeks before therapy. Subsets of rabbits from each group underwent perfusion-fixation and harvesting of the thoracic aorta for morphometric and immunohistochemical analyses at 7 or 21 days.The mean plaque area was 15.75+/-2.28% and 22.00+/-3.24% with VEGF and 0.67+/-0.22% and 1.17+/-0.34% with albumin at 7 and 21 days, respectively. The plaque circumference was 13.00+/-2.58% and 23.75+/-2.86% with VEGF and 2.50+/-0.65% and 6.25+/-1.88% with albumin at 7 and 21 days, respectively. The maximal plaque thickness was 0.11+/-0.002 and 0.15+/-0.007 mm with VEGF and 0.04+/-0.009 and 0.07+/-0.003 mm with albumin at 7 and 21 days, respectively. The endothelial density (reported as percent total plaque area) was 31.75+/-4.42% and 63.00+/-8.45% with VEGF and 7.75+/-1.65% and 12.75+/-1.93% with albumin at 7 and 21 days, respectively. The macrophage density was 4.5+/-0.86 and 19.25+/-1.54 with VEGF and 4.26+/-0.75 and 6.00+/-1.08 with albumin at 7 and 21 days, respectively.Recombinant human VEGF increases the rate and degree of atherosclerotic plaque formation in the thoracic aorta in a cholesterol-fed rabbit model.

    View details for Web of Science ID 000169268300020

    View details for PubMedID 11419898

  • Isolated lower extremity chemotherapeutic infusion for treatment of osteosarcoma: Experimental study and preliminary clinical report JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, M. Q., Dake, M. D., Wang, Z. P., Cui, Z. P., Gao, Y. A. 2001; 12 (6): 731-737


    To increase the dose of drug delivered to a tumor while maintaining tolerable systemic side effects, an interventional technique of isolated lower extremity infusion was investigated.Experiments were performed in eight dogs. Four dogs were treated by a combination of intraarterial (IA) femoral cisplatin infusion at a dose of 2.0 mg/kg with drug removal from the ipsilateral extremity venous blood by a dialyzer. The other four dogs comprised the control group. In these animals, left femoral arterial IA cisplatin infusion was performed without dialysis. Leukocyte and platelet counts, blood urea nitrogen (BUN) levels, and serum creatinine levels were recorded before and after the treatment. Subsequently, two human patients with inoperable osteosarcoma were treated with the isolated infusion.In the experiments, 85%-90% of the free platinum that entered the dialyzer was removed. The peak systemic plasma cisplatin concentrations in animals undergoing dialysis were reduced by 81.25% compared to those in animals undergoing femoral IA infusion without hemodialysis. There were no significant changes in the hematologic profiles or BUN and serum creatinine levels in the experimental animals. However, in the control group, all dogs developed myelosuppression and severe renal toxicity after IA infusion of the same dose of cisplatin. Clinically, immediate relief of symptoms related to the primary tumor was achieved in both human patients after the combination of isolated IA infusion and embolotherapy.Single-pass hemodialysis removed a significant amount of cisplatin after regional IA infusion, reduced systemic toxicity, and permitted survival of the experimental animals. In two patients with osteosarcoma, percutaneous isolated lower extremity chemotherapeutic infusion therapy and embolotherapy were performed safely with partial responses.

    View details for Web of Science ID 000169041500008

    View details for PubMedID 11389225

  • High-efficiency endovascular gene delivery via therapeutic ultrasound JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Amabile, P. G., Waugh, J. M., Lewis, T. N., Elkins, C. J., Janas, W., Dake, M. D. 2001; 37 (7): 1975-1980


    We studied enhancement of local gene delivery to the arterial wall by using an endovascular catheter ultrasound (US).Ultrasound exposure is standard for enhancement of in vitro gene delivery. We postulate that in vivo endovascular applications can be safely developed.We used a rabbit model of arterial mechanical overdilation injury. After arterial overdilation, US catheters were introduced in bilateral rabbit femoral arteries and perfused with plasmidor adenovirus-expressing blue fluorescent protein (BFP) or phosphate buffered saline. One side received endovascular US (2 MHz, 50 W/cm2, 16 min), and the contralateral artery did not.Relative to controls, US exposure enhanced BFP expression measured via fluorescence 12-fold for plasmid (1,502.1+/-927.3 vs. 18,053.9+/-11,612 microm2, p < 0.05) and 19-fold for adenovirus (877.1+/-577.7 vs. 17,213.15+/-3,892 microm2, p < 0.05) while increasing cell death for the adenovirus group only (26+/-5.78% vs. 13+/-2.55%, p < 0.012).Endovascular US enhanced vascular gene delivery and increased the efficiency of nonviral platforms to levels previously attained only by adenoviral strategies.

    View details for Web of Science ID 000169097200034

    View details for PubMedID 11401141

  • Successful treatment for bronchial bleeding from invasive pulmonary metastasis of hepatocellular carcinoma: A case report HEPATO-GASTROENTEROLOGY Kawaguchi, T., Tanaka, M., Itano, S., Ono, N., Shimauchi, Y., Nagamatsu, H., Sakisaka, S., Dake, M. D., Tanikawa, K., Sata, M. 2001; 48 (39): 851-853


    Pulmonary metastasis is frequently seen in patients with advanced hepatocellular carcinoma. However, information is limited concerning life-threatening complications and effective treatment of pulmonary metastasis because of the poor prognosis of patients with advanced hepatocellular carcinoma. Recent remarkable progress in detection and treatment of hepatocellular carcinoma has improved prognosis, making management of pulmonary metastasis an important clinical issue. We describe a 68-year-old man with pulmonary metastasis of hepatocellular carcinoma and sudden onset of hemoptysis from bronchial invasion. Transcatheter embolization was performed successfully via the bronchial artery with disappearance of bloody sputum. Peribronchial pulmonary metastasis of hepatocellular carcinoma can cause life-threatening hemoptysis. Transcatheter arterial embolization may be one of therapeutics for hemoptysis from invasive pulmonary metastasis of hepatocellular carcinoma.

    View details for Web of Science ID 000169631600058

    View details for PubMedID 11462940

  • Delayed complications after esophageal stent placement for treatment of malignant esophageal obstructions and esophagorespiratory fistulas JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, M. Q., Sze, D. Y., Wang, S. P., Wang, Z. Q., Gao, Y. A., Dake, M. D. 2001; 12 (4): 465-474


    To evaluate delayed complications after esophageal expandable metallic stent placement.From April 1993 to December 1997, 90 expandable metallic stents were placed in 82 consecutive patients with inoperable malignant esophageal obstruction (n = 49) or malignant esophagorespiratory fistula (n = 33). Stents used included covered Gianturco-Rosch Z stents (n = 20), Wallstents (covered, n = 31; uncovered, n = 13), and Ultraflex stents (covered, n = 8; uncovered, n = 10). Patients were followed prospectively and monitored for delayed complications, defined as major (hemorrhage, tracheal compression, stent migration, perforation or fistula formation, granulomatous obstruction, tumor ingrowth and overgrowth, funnel phenomenon, and stent covering disruption) or minor (reflux, chest pain, and food impaction).Mean survival was 4.5 months after stent placement (range, 3 weeks to 26 months). The overall incidence of delayed complications was 64.6%, with 17 patients (20.7%) experiencing more than one complication. The rates of delayed complications in patients with Z stents, Wallstents, and Ultraflex stents were 75.0%, 68.1%, and 44.4%, respectively (P <.05). Most complications were life-threatening and occurred more frequently when stents were placed in the proximal third of the esophagus, compared with more distally (P <.05). Thirteen patients (15.9%) died from complications directly related to stent placement.Esophageal stent placement for malignant obstruction or fistula is associated with a substantial incidence of delayed complications.

    View details for Web of Science ID 000167928600010

    View details for PubMedID 11287534

  • Vascular endothelial growth factor enhances atherosclerotic plaque progression NATURE MEDICINE Celletti, F. L., Waugh, J. M., Amabile, P. G., Brendolan, A., Hilfiker, P. R., Dake, M. D. 2001; 7 (4): 425-429


    Vascular endothelial growth factor (VEGF) can promote angiogenesis but may also exert certain effects to alter the rate of atherosclerotic plaque development. To evaluate this potential impact on plaque progression, we treated cholesterol-fed mice doubly deficient in apolipoprotein E/apolipoprotein B100 with low doses of VEGF (2 microg/kg) or albumin. VEGF significantly increased macrophage levels in bone marrow and peripheral blood and increased plaque area 5-, 14- and 4-fold compared with controls at weeks 1, 2 and 3, respectively. Plaque macrophage and endothelial cell content also increased disproportionately over controls. In order to confirm that the VEGF-mediated plaque progression was not species-specific, the experiment was repeated in cholesterol-fed rabbits at the three-week timepoint, which showed comparable increases in plaque progression.

    View details for Web of Science ID 000167960500036

    View details for PubMedID 11283668

  • Enhancement of neointima formation with tissue-type plasminogen activator JOURNAL OF VASCULAR SURGERY Hilfiker, P. R., Waugh, J. M., Li-Hawkins, J. J., Kuo, M. D., Yuksel, E., Geske, R. S., Cifra, P. N., Chawla, M., Weinfeld, A. B., Thomas, J. W., Shenaq, S. M., Dake, M. D. 2001; 33 (4): 821-828


    Indirect evidence suggests that tissue plasminogen activator (tPA) either limits or does not alter restenosis. However, tPA enhances tumor invasiveness through matrix remodeling, and several elements of degraded matrix enhance smooth muscle cell mitogenesis. We use either local adenoviral-mediated overexpression of tPA or systemic infusion of recombinant tPA combined with mechanical overdilation of rabbit common femoral arteries to evaluate the impact of tPA on neointima formation.Left common femoral arteries of New Zealand white rabbits were transfected in situ either with an adenoviral-construct-expressing tPA or a viral control (adenoviral-construct-expressing beta-galactosidase) or nonviral (buffer) control after balloon angioplasty injury. At 7 and 28 days, left common femoral artery segments were harvested (n = 4 for each group and time point). Vessel segments were examined for intimato-media ratio, smooth muscle cell proliferation, extracellular matrix, and inflammatory response. Thrombus formation was evaluated after 3 days (n = 3 for each group). In a second experiment, New Zealand white rabbits (n = 3 per group, per time point) underwent mechanical dilation followed by buffer treatment or systemic tPA infusion according to a widely clinically used accelerated infusion protocol. Treated artery segments were harvested after 7 or 28 days and processed for intima-to-media ratio determination and class-wide histochemical determination of collagenous extracellular matrix and collagen content.Both rate and degree of neointima formation increase dramatically with overexpression (250%-461% relative to controls at 7 and 28 days). Substantial early matrix degradation is observed in vessels treated with local overexpression of tPA, although no increases in local inflammation or in smooth muscle proliferation occur. Late enhancement of smooth muscle proliferation emerges, consistent with secondary impact of perturbed matrix components. Systemic infusion of tPA according to clinical protocols also results in early and late enhancement of neointima formation in this model (34%-52% relative to controls at at 7 and 28 days), with significant early collagenous matrix degradation. Systemic infusion, although significant, did not attain the degree of neointima formation present with overexpression.With some evidence of dose-dependence, tissue plasminogen activator enhances neointima formation after angioplasty in a rabbit model. Early matrix degradation precedes change in rates of proliferation and underlies this effect in spite of several antirestenotic actions including decreased thrombus and decreased macrophage recruitment in this model.

    View details for DOI 10.1067/mva.2001.112323

    View details for Web of Science ID 000168027000024

    View details for PubMedID 11296338

  • Perivascular release of insulin-like growth factor-1 limits neointima formation in the balloon-injured artery by redirecting smooth muscle cell migration JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wong, A. H., Amabile, P. G., Yuksel, E., Waugh, J. M., Dake, M. D. 2001; 12 (3): 347-350


    Insulin-like growth factor-1 (IGF-1) is a potent chemoattractant to vascular smooth muscle cells (SMCs). The authors hypothesize that perivascular release of IGF-1 in vivo can direct migration of SMCs away from the lumen and reduce neointima formation in a rabbit model of arterial balloon injury.Balloon angioplasty of the common femoral arteries was performed in adult male New Zealand White rabbits (n = 8 per treatment group) and controlled release microspheres delivering either IGF-1 or blank control treatment were implanted perivascularly at the angioplasty site prior to surgical closure. At 7 days, five arteries per group were harvested and cross-sections were subjected to anti-PCNA (proliferating cell nuclear antigen) immunostaining to determine the number and distribution of proliferating SMCs. At 28 days, the remaining three arteries per group were harvested and sections were evaluated for intima-to-media (I/M) ratios by means of VVG-Masson staining. One-way analysis of variance with Fisher protected least significant difference post hoc testing was used to determine statistical significance at P < .05.At 7 days, PCNA(+) medial SMCs assumed a significantly more peripheral (ie, further from lumen) distribution in the vessel wall with use of perivascular IGF-1 than with use of blank treatment (P < .05). Overall SMC proliferation was not significantly different, thus the change in distribution was likely due to directionally altered SMC migration. At 28 days, perivascular IGF-1 significantly decreased I/M ratios by 44% relative to control treatment (P < .05).Perivascular release of IGF-1 can directionally guide SMC migration away from the lumen and reduce neointima in the balloon-injured artery. This novel strategy might have implications in the development of antirestenosis therapies.

    View details for Web of Science ID 000167481400012

    View details for PubMedID 11287513

  • Update on the bifurcated EXCLUDER endoprosthesis: Phase I results JOURNAL OF VASCULAR SURGERY Matsumura, J. S., Katzen, B. T., Hollier, L. H., Dake, M. D. 2001; 33 (2): S150-S153


    Many devices are being investigated for treatment of infrarenal abdominal aortic aneurysms. This report describes the particular characteristics of a next generation modular endograft and the Phase I results in 29 patients. Larger comparative studies are in progress to assess the safety and efficacy of this new design.

    View details for Web of Science ID 000167332500022

    View details for PubMedID 11174827

  • Guided remodeling using local overexpression of tissue plasminogen activator prevents neointima formation in arterialized vein grafts Miniati, D. N., Koransky, M. L., Kown, M., Park, A. K., Kuo, M. D., Waugh, J. M., Woo, S. L., Dake, M. D., Robbins, R. C. LIPPINCOTT WILLIAMS & WILKINS. 2000: 146–47
  • Peripheral arterial obstruction: Prospective study of treatment with a transluminally placed self-expanding stent-graft RADIOLOGY Lammer, J., Dake, M. D., Bleyn, J., Katzen, B. T., Cejna, M., Piquet, P., Becker, G. J., Settlage, R. A. 2000; 217 (1): 95-104


    To evaluate the safety and efficacy of an endoluminal prosthesis for treatment of peripheral arterial occlusive disease (PAOD).A self-expanding endoprosthesis with an expanded polytetrafluoroethylene tube inside a nitinol support structure was implanted in 127 patients with symptomatic PAOD in the iliac (61 limbs) and femoral arteries (80 limbs). Clinical category status, ankle-brachial index, and color duplex flow imaging results were recorded before treatment, at discharge, and at 1, 3, 6, and 12 months after treatment. Aspirin was administered throughout the study, and heparin was administered during and for 2 days after the procedure.Endoprosthesis deployment was technically successful in all patients. Complications occurred in 24 of 141 procedures and included three major complications. Early thrombosis (within 30 days) occurred in one iliac and three femoral arteries. Late restenosis or reocclusion was observed in five iliac and 14 femoral arteries within the 1st year. Primary patency rates in iliac arteries were 98% +/- 3% (standard error) and 91% +/- 4%, respectively, at 6 and 12 months after treatment. Primary patency rates in femoral arteries were 90% +/- 3% and 79% +/- 5%, respectively, at 6 and 12 months. Secondary patency rates were 95% and 93% for iliac and femoral arteries, respectively, at 12 months after treatment.The device used in this study can be implanted without additional risks to the patient and provided encouraging patency rates up to 1 year.

    View details for Web of Science ID 000089452500017

    View details for PubMedID 11012429

  • Mesenteric and portal venous thrombosis treated by transjugular mechanical thrombolysis AMERICAN JOURNAL OF ROENTGENOLOGY Sze, D. Y., O'Sullivan, G. J., Jahnson, D. L., Dake, M. D. 2000; 175 (3): 732-734

    View details for Web of Science ID 000088910300026

    View details for PubMedID 10954458

  • Thrombomodulin overexpression to limit neointima formation CIRCULATION Waugh, J. M., Li-Hawkins, J., Yuksel, E., Kuo, M. D., Cifra, P. N., Hilfiker, P. R., Geske, R., Chawla, M., Thomas, J., Shenaq, S. M., Dake, M. D., Woo, S. L. 2000; 102 (3): 332-337


    BACKGROUND-These studies were initiated to confirm that high-level thrombomodulin overexpression is sufficient to limit neointima formation after mechanical overdilation injury. METHODS AND RESULTS-An adenoviral construct expressing thrombomodulin (Adv/RSV-THM) was created and functionally characterized in vitro and in vivo. The impact of local overexpression of thrombomodulin on neointima formation 28 days after mechanical overdilation injury was evaluated. New Zealand White rabbit common femoral arteries were treated with buffer, viral control, or Adv/RSV-THM and subjected to mechanical overdilation injury. The treated vessels (n=4 per treatment) were harvested after 28 days and evaluated to determine intima-to-media (I/M) ratios. Additional experiments were performed to determine early (7-day) changes in extracellular elastin and collagen content; local macrophage, T-cell, and neutrophil infiltration; and local thrombus formation as potential contributors to the observed impact on 28-day neointima formation. The construct significantly decreased neointima formation after mechanical dilation injury in this model. By histological analysis, buffer controls exhibited mean I/M ratios of 0.76+/-0.06%, whereas viral controls reached 0.77+/-0.08%; in contrast, Adv/RSV-THM reduced I/M ratios to 0.47+/-0.06%. Local inflammatory infiltrate decreased in the Adv/RSV-THM group relative to controls, whereas matrix remained relatively preserved. Rates of early thrombus formation also decreased in Adv/RSV-THM animals. CONCLUSIONS-This construct thus offers a viable technique for promoting a locally neointima-resistant small-caliber artery via decreased thrombus bulk, normal matrix preservation, and decreased local inflammation without the inflammatory damage that has limited many other adenoviral applications.

    View details for Web of Science ID 000088210200012

    View details for PubMedID 10899098

  • Endovascular management of iliac vein compression (May-Thurner) syndrome JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY O'Sullivan, G. J., Semba, C. P., Bittner, C. A., Kee, S. T., Razavi, M. K., Sze, D. Y., Dake, M. D. 2000; 11 (7): 823-836


    To evaluate the feasibility of endovascular techniques in treating venous outflow obstruction resulting from compression of the iliac vein by the iliac artery of the left lower extremity (May-Thurner syndrome).A retrospective analysis of 39 patients (29 women, 10 men; median age, 46 years) with iliac vein compression syndrome (IVCS) was performed. Nineteen patients presented with acute deep vein thrombosis (DVT) and 20 patients presented with chronic symptoms. All patients presented with leg edema or pain. In the acute group, patients were treated with catheter-directed thrombolysis (120,000-180,000 IU urokinase/h) and angioplasty followed by stent placement. In the chronic group, patients were treated with use of angioplasty and stent placement alone (n = 8), or in combination with thrombolysis (n = 12). Patients were then followed-up with duplex ultrasound and a quality-of-life assessment.Initial technical success was achieved in 34 of 39 patients (87%). The overall patency rate at 1 year was 79%. Symptomatically, 85% of patients were completely or partially improved compared with findings before treatment. Thirty-five of 39 patients received stents. The 1-year patency rate for patients with acute symptoms who received stents was 91.6%; for patients with chronic symptoms who received stents, the 1-year patency rate was 93.9%. Five technical failures occurred. Major complications included acute iliac vein rethrombosis (< 24 hours) requiring reintervention (n = 2). Minor complications included perisheath hematomas (n = 4) and minor bleeding (n = 1). There were no deaths, pulmonary embolus, cerebral hemorrhage, or major bleeding complications.Endovascular reconstruction of occluded iliac veins secondary to IVCS (May-Thurner) appears to be safe and effective.

    View details for Web of Science ID 000088217200002

    View details for PubMedID 10928517

  • Stent-graft therapy for subclavian artery aneurysms and fistulas: Single-center mid-term results JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Hilfiker, P. R., Razavi, M. K., Kee, S. T., Sze, D. Y., Semba, C. P., Dake, M. D. 2000; 11 (5): 578-584


    To evaluate the potential of covered stents to replace surgery in the treatment of subclavian artery aneurysms and traumatic injuries.Nine patients (five men, four women; age range, 20-83 years; mean, 54 years) with subclavian artery aneurysms (n = 5) or fistulas (n = 4) were treated with stent-grafts. All devices used were custom-made, consisting of polytetrafluoroethylene (PTFE)-covered Palmaz (n = 5), Wallstent (n = 2), Z stents (n = 8), or a polyester-covered Z stent (n = 1). One patient was lost to follow-up after 2 months. All others were followed up with clinical evaluation, computed tomography (CT), and/or ultrasound.All devices were deployed successfully with exclusion of the aneurysms and fistulas. There were two procedure-related complications (22%), consisting of groin pseudoaneurysms requiring surgical repair 3 and 9 days after the procedure. One of those patients required additional oral antibiotic therapy for a postsurgical groin wound infection. One patient developed a stenosis at 12 months, which required angioplasty. The stent-graft thrombosed in one patient because of a kink 2 months after placement, which was successfully treated by thrombolysis and placement of a Wallstent. The primary and secondary patencies are 89% and 100%, respectively, after a mean follow-up of 29 months (2-66 mo).Mid-term results of stent-graft therapy of subclavian artery aneurysms and fistulas are encouraging, with low morbidity and excellent clinical outcome.

    View details for Web of Science ID 000087118200006

    View details for PubMedID 10834488

  • Internal iliac artery embolization in the stent-graft treatment of aortoiliac aneurysms: Analysis of outcomes and complications JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Razavi, M. K., DeGroot, M., Olcott, C., Sze, D., Kee, S., Semba, C. P., Dake, M. D. 2000; 11 (5): 561-566


    To analyze the complications of internal iliac artery (IIA) embolization in conjunction with stent-graft treatment of aortoiliac aneurysms.Seventy-one patients with aortoiliac (n = 47) or iliac (n = 24) aneurysms were treated with endoluminal placement of stent-grafts. Thirty-two patients (31 men, one woman; mean age, 73 years; range, 56-88 years) had embolization or occlusion of one (n = 27) or both (n = 5) IIAs. Status of the IIAs and the collateral circulation was assessed by retrospective review of angiographic images. Follow-up consisted of a standardized patient questionnaire and review of radiologic and medical records.The mean follow-up time was 35 months (range, 5-64 months). Eleven of the 47 patients with abdominal aortic aneurysms (AAA) (23%) and 19 of the 24 patients with iliac aneurysms (79%) required IIA embolization. One patient with AAA and another with iliac aneurysm had unintentional occlusion of an IIA by extension of the stent-graft over their origins. A total of seven patients had bilateral occlusion of the IIAs after the procedure. Additionally, the inferior mesenteric arteries (IMAs) of two other patients with AAA were also embolized. In six patients, all three vessels were occluded after placement of the stent-grafts. Symptoms were reported in nine of the 20 (45%) patients with iliac aneurysms and in three of the 12 (25%) patients with AAA. Symptoms consisted of buttock claudication (nine of 32, 28%), new sexual dysfunction (two of 16, 12%), and transient urinary retention (3%). Seven of the claudicants had resolution of symptoms after a mean interval of 14 months (range, 1-36 months). There were no instances of bowel ischemia, neurologic sequelae, or buttock necrosis related to these procedures.Embolization of the IIA is associated with symptoms in a significant number of patients. While symptoms are transient in most patients, they can be problematic. Efforts should be made to preserve the pelvic circulation if possible.

    View details for Web of Science ID 000087118200003

    View details for PubMedID 10834485

  • Endovascular stent-graft placement for treatment of traumatic penetrating subclavian artery injury JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE Stecco, K., Meier, A., Seiver, A., Dake, M., Zarins, C. 2000; 48 (5): 948-950

    View details for Web of Science ID 000087080200036

    View details for PubMedID 10823542

  • Cost identification of abdominal aortic aneurysm imaging by using time and motion analyses RADIOLOGY Rubin, G. D., Armerding, M. D., Dake, M. D., Napel, S. 2000; 215 (1): 63-70


    To compare the costs of performing helical computed tomographic (CT) angiography with three-dimensional rendering versus intraarterial digital subtraction angiography (DSA) for preoperative imaging of abdominal aortic aneurysms (AAAs).A single observer determined the variable direct costs of performing nine intraarterial DSA and 10 CT angiographic examinations in age- and general health-matched patients with AAA by using time and motion analyses. All personnel directly involved in the cases were tracked, and the involvement times were recorded to the nearest minute. All material items used during the procedures were recorded. The cost of labor was determined from personnel reimbursement data, and the cost of materials, from vendor pricing. The variable direct costs of laboratory tests and using the ambulatory treatment unit for postprocedural monitoring, as well as all fixed direct costs, were assessed from hospital accounting records. The total costs were determined for each procedure and compared by using the Student t test and calculating the CIs.The mean total direct cost of intraarterial DSA (+/- SD) was $1,052 +/- 71, and that of CT angiography was $300 +/- 30, which are significantly different (P < 4.1 x 10(-11)). With 95% confidence, intraarterial DSA cost 3.2-3.7 times more than CT angiography for the assessment of AAA.Assuming equal diagnostic utility and procedure-related morbidity, institutions may have substantial cost savings whenever CT angiography can replace intraarterial DSA for imaging AAAs.

    View details for Web of Science ID 000086156700011

    View details for PubMedID 10751469

  • Aortic aneurysmal disease: Assessment of stent-graft treatment - CT versus conventional angiography RADIOLOGY Armerding, M. D., Rubin, G. D., Beaulieu, C. F., Slonim, S. M., Olcott, E. W., Samuels, S. L., Jorgensen, M. J., Semba, C. P., Jeffrey, R. B., Dake, M. D. 2000; 215 (1): 138-146


    To compare computed tomographic (CT) angiography and conventional angiography for determining the success of endoluminal stent-graft treatment of aortic aneurysms.Forty patients underwent conventional angiography and CT angiography following treatment of aortoiliac aneurysms with endoluminal stent-grafts. Six additional sets of conventional angiographic-CT angiographic examinations were performed in five patients after placement of additional stent-grafts or coil embolization to treat perigraft leakage. Three faculty CT radiologists who were blinded to patient clinical data and outcome independently interpreted the CT angiograms, and three faculty angiographers, who were not involved in the stent-graft deployment, interpreted the conventional angiograms. Images were assessed for the presence of postdeployment complications. A reference standard was developed by experienced radiologists using all available images and clinical data. Sensitivities, specificities, and kappa values were calculated.Perigraft leakage was the most commonly identified complication. Twenty perigraft leaks were detected in the results of 46 examinations. Sensitivities and specificities for detecting perigraft leakage were 63% and 77% for conventional angiography and 92% and 90% for CT angiography, respectively. The kappa value was 0. 41 for conventional angiography and 0.81 for CT angiography.CT angiography is the preferred method for establishing the presence of perigraft leakage following treatment of aortoiliac aneurysms with stent-grafts.

    View details for Web of Science ID 000086156700021

    View details for PubMedID 10751479

  • Placement of SVC stents over pacemaker wires for the treatment of SVC syndrome JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Slonim, S. M., Semba, C. P., Sze, D. Y., Dake, M. D. 2000; 11 (2): 215-219

    View details for Web of Science ID 000085585200011

    View details for PubMedID 10716393

  • True-lumen collapse in aortic dissection - Part I. Evaluation of causative factors in phantoms with pulsatile flow RADIOLOGY Chung, J. W., Elkins, C., Sakai, T., Kato, N., Vestring, T., Semba, C. P., Slonim, S. M., Dake, M. D. 2000; 214 (1): 87-98


    To investigate the causative factors in true-lumen collapse in a model of aortic dissection.Phantoms with an aortic arch, true and false lumina with abdominal branch vessels, and a distal bifurcation were used to model a Stanford type B aortic dissection. The effects of anatomic factors (entry-tear size, branch-vessel flow distribution, fenestrations, distal reentry communication) and physiologic factors (peripheral resistance in the branch vessels, pump output and rate, vascular compliance) on true-lumen collapse were investigated. The morphology of the true lumen was observed. Branch pressures and flow rates were measured.True-lumen collapse was induced and was exacerbated by an increase in the size of the entry tear, a decrease in the false-lumen outflow caused by occluding the false-lumen branch vessels, and an increase in the true-lumen outflow caused by lowering the peripheral resistance in true-lumen branch vessels. Two kinds of true-lumen collapse depended on pump output. With low pump output and low outflow resistance from the true lumen, the true lumen collapsed. With high pump output and low inflow resistance in the false lumen, the true lumen was compressed. Distal reentry communication between the true and false limbs was more effective than aortic fenestrations in preventing true-lumen collapse.True-lumen collapse in this dissection model strongly depends on the difference in the ratios of inflow capacity to outflow capacity in the true and false lumina. Both anatomic and physiologic factors can affect true-lumen collapse.

    View details for Web of Science ID 000084414400015

    View details for PubMedID 10644106

  • Chronically occluded inferior venae cavae: Endovascular treatment RADIOLOGY Razavi, M. K., Hansch, E. C., Kee, S. T., Sze, D. Y., Semba, C. P., Dake, M. D. 2000; 214 (1): 133-138


    To report the results of endoluminal recanalization and stent placement in patients with chronic occlusions of the inferior vena cava (IVC).Seventeen consecutive patients (12 male, five female patients; mean age, 40.6 years; age range, 15-77 years) with chronic IVC occlusions were treated during a 6-year period. The mean duration of symptoms was 32 months. Underlying active malignancy was the cause of occlusion in four patients. Five patients with superimposed acute thrombus underwent catheter-directed thrombolysis prior to IVC recanalization. Clinical patency was defined as absence or improvement of symptoms. Clinical follow-up was supplemented with ultrasonography, vena cavography, or both in 10 patients.Technical success was achieved in 15 (88%) patients. Additional thrombolytic therapy and stent placement was needed in two patients to maintain patency at 4 and 6 months after the procedure. Twelve patients had IVCs that remained patent after a mean follow-up of 19 months for a primary patency rate of 80%. The primary assisted patency rate was 87% (13 of 15). There were four deaths owing to underlying disease 6-21 months after the procedures. There were no procedure-related complications.Endoluminal recanalization and stent placement in chronically occluded IVCs has a good intermediate-term outcome and should be considered in patients who have symptoms and who often do not have adequate alternative therapy.

    View details for Web of Science ID 000084414400021

    View details for PubMedID 10644112

  • True-lumen collapse in aortic dissection - Part II. Evaluation of treatment methods in phantoms with pulsatile flow RADIOLOGY Chung, J. W., Elkins, C., Sakai, T., Kato, N., Vestring, T., Semba, C. P., Slonim, S. M., Dake, M. D. 2000; 214 (1): 99-106


    To discover and evaluate the effective treatment methods to prevent or relieve true-lumen collapse in models of aortic dissection.Two phantoms were built to simulate type B aortic dissection. After true-lumen collapse was induced, experiments were conducted to evaluate the effectiveness of clinically relevant variables in relieving the collapse. Variables included entry-tear size, branch-vessel flow distribution, distal reentry communication between the true and false limbs, aortic fenestrations, and pump output. To test the effect of closing the entry tear, a stent-graft was deployed over the entry tear under physiologic conditions in a mock-flow loop. The difference in the effect of each variable on the prevention and relief of true-lumen collapse was also investigated.It was more difficult to relieve true-lumen collapse than it was to prevent it. Placement of a stent-graft over the entry tear was the most effective method of relieving true-lumen collapse. Less-effective procedures included opening a false-lumen outflow branch and opening the distal reentry branch. Opening the fenestration-branch loops, meant to simulate the creation of artificial fenestrations in the intimal flap, did not relieve true-lumen collapse.The definitive treatment for true-lumen collapse in aortic dissection is direct repair of the entry tear to decrease false-lumen inflow. Otherwise, increasing the false-lumen outflow and/or creating distal fenestrations between the true and false lumina distal to the level of the compromised aortic branch are less-effective alternatives.

    View details for Web of Science ID 000084414400016

    View details for PubMedID 10644107

  • Local overexpression of thrombomodulin for in vivo prevention of arterial thrombosis Waugh, J. M., Yuksel, E., Li, J., Kuo, M. D., Hilfiker, P. R., Kattash, M. I., Saxena, R., Geske, R., Thung, S. N., Shenaq, S. M., Dake, M. D., Woo, S. L. LIPPINCOTT WILLIAMS & WILKINS. 1999: 472–72
  • Local overexpression of thrombomodulin for in vivo prevention of arterial neointima formation Waugh, J. M., Li, J., Yuksel, E., Kuo, M. D., Cifra, P. N., Hilfiker, P. R., Geske, R., Thomas, J., Shenaq, S. M., Dake, M. D., Woo, S. L. LIPPINCOTT WILLIAMS & WILKINS. 1999: 546–46
  • Local overexpression of elastase inhibitors for in vivo prevention of neointima formation after mechanical overdilation Waugh, J. M., Li, J., Yuksei, E., Kuo, M. D., Cifra, P. N., Hilfiker, P. R., Geske, R., Thomas, J., Dake, M. D., Woo, S. L. LIPPINCOTT WILLIAMS & WILKINS. 1999: 700–701
  • Diagnostic yield of MR-guided liver biopsies compared with CT- and US-guided liver biopsies 1999 SCVIR Annual Meeting Schmidt, A. J., Kee, S. T., Sze, D. Y., Daniel, B. L., Razavi, M. K., Semba, C. P., Dake, M. D. ELSEVIER SCIENCE INC. 1999: 1323–29


    To compare diagnostic yield and complication rates of magnetic resonance (MR)-guided versus computed tomography (CT)- and ultrasound (US)-guided liver biopsies.MR-, CT-, and US-guided liver biopsies performed between 9/96 and 9/98 were compared. Sixty patients (21 men and 39 women, mean age 60 years) underwent MR-guided biopsy of liver lesions. Thirty patients (16 men and 14 women, mean age 59 years) underwent CT-guided biopsy. Eighteen patients (seven men and 11 women, mean age 50 years) underwent US-guided biopsy. MR procedures were performed in an open-configuration 0.5-T Signa SP MR unit. Lesion localization used standard T1 and T2 sequences, whereas biopsies were performed with multiplanar spoiled gradient recalled echo and fast gradient recalled echo sequences. A coaxial system with an MR-compatible 18-gauge stabilizing needle and a 21-gauge aspiration needle was used to obtain all samples. In CT and US procedures, a 19-gauge stabilizing needle and a 21-gauge aspiration or a 20-gauge core biopsy needle were used. A cytotechnologist was present to determine the adequacy of samples.MR had a diagnostic yield of 61%. CT and US had diagnostic yields of 67% and 61%, respectively. No serious complications were reported for MR and US procedures. Two CT biopsies resulted in postprocedural hemorrhage. One patient required surgical exploration and died.MR-guided biopsy of liver lesions with use of a 0.5-T open-configuration magnet is safe and accurate when compared with CT and US. No statistical difference was observed between the diagnostic yield of biopsies performed with MR, CT, and US guidance. MR enabled biopsy of a number of lesions in the hepatic dome and lesions with low contrast, which would normally be difficult to sample safely with use of CT or US.

    View details for Web of Science ID 000083881500004

    View details for PubMedID 10584646

  • Endovascular treatment of hepatic venous outflow obstruction after piggyback technique liver transplantation TRANSPLANTATION Sze, D. Y., Semba, C. P., Razavi, M. K., Kee, S. T., Dake, M. D. 1999; 68 (3): 446-449


    The piggyback technique of orthotopic liver transplantation is an attractive alternative that preserves the recipient inferior vena cava and allows uninterrupted venous blood return during the anhepatic phase. As with other transplantation techniques, the vascular anastomoses required by the piggyback technique can develop strictures.Review of records of 264 piggyback transplantations revealed two cases of delayed-onset hepatic venous obstruction from anastomotic strictures. Both patients also had symptoms of inferior vena cava obstruction, with azotemia and lower extremity edema. Both patients were treated percutaneously with balloon-expandable stents.Rapid, dramatic resolution of symptoms was achieved in both patients. Patients remain completely asymptomatic at 39 and 3 months of follow-up.Hepatic venous anastomotic strictures in recipients of piggyback technique transplants are a very uncommon complication. They may be easily and effectively treated by minimally invasive endovascular intervention.

    View details for Web of Science ID 000082050600018

    View details for PubMedID 10459550

  • Management of misplaced or migrated endovascular stents JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Slonim, S. M., Dake, M. D., Razavi, M. K., Kee, S. T., Samuels, S. L., Rhee, J. S., Semba, C. P. 1999; 10 (7): 851-859


    To report experience with techniques for management of misplaced or migrated endovascular stents.During a 5-year period, percutaneous management of 27 misplaced or migrated endovascular stents (16 Palmaz, 11 Wallstents) in 25 patients was attempted. The 17 venous and 10 arterial stents were rescued from the aorta (n = 9), inferior vena cava (IVC) (n = 4), transjugular intrahepatic portosystemic shunt/IVC (n = 2), right atrium (n = 3), right ventricle (n = 2), pulmonary artery (n = 2), iliac vein (n = 2), iliac artery (n = 1), superior vena cava (n = 1), and superior mesenteric vein (n = 1).Stent management was successful in 26 of 27 cases (96%). Eleven stents were removed percutaneously, two were repositioned and removed with a minor surgical procedure, and 13 were repositioned and deployed in a stable alternate location. The only complication was the development of tricuspid insufficiency in the single case in which the procedure failed (4% complication rate). This patient's stent was eventually surgically removed from the right ventricle.Misplaced or migrated endovascular Palmaz and Wallstents can be effectively managed with few complications by using a variety of percutaneous techniques.

    View details for Web of Science ID 000081558900002

    View details for PubMedID 10435701

  • Recurrent TIPS failure associated with biliary fistulae: Treatment with PTFE-covered stents CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Sze, D. Y., Vestring, T., Liddell, R. P., Kato, N., Semba, C. P., Razavi, M. K., Kee, S. T., Dake, M. D. 1999; 22 (4): 298-304


    To evaluate the efficacy of covered stents for the treatment of transjugular intrahepatic portosystemic shunt (TIPS) obstruction in human subjects with identified or suspected biliary fistulae.Five patients were treated for early failure of TIPS revisions. All had mid-shunt thrombus, and four of these had demonstrable biliary fistulae. Three patients also propagated thrombus into the native portal venous system and required thrombolysis. TIPS were revised in four patients using a custom-made polytetrafluoroethylene (PTFE)-covered Wallstent, and in one patient using a custom-made PTFE-covered Gianturco Z-stent.All identified biliary fistulae were successfully sealed. All five patients maintained patency and function of the TIPS during follow-up ranging from 2 days to 21 months (mean 8.4 months). No patient has required additional revision. Thrombosis of the native portal venous system was treated with partial success by mechanical thrombolysis.Early and recurrent failure of TIPS with mid-shunt thrombosis, which may be associated with biliary fistulae, can be successfully treated using covered stents. Stent-graft revision appears to be safe, effective, and potentially durable.

    View details for Web of Science ID 000081733100006

    View details for PubMedID 10415219

  • Descending thoracic aortic aneurysm: Thoracic CT findings after endovascular stent-graft placement RADIOLOGY Sakai, T., Dake, M. D., Semba, C. P., Yamada, T., ARAKAWA, A., Kee, S. T., Hayashi, N., Razavi, M. K., Sze, D. Y. 1999; 212 (1): 169-174


    To evaluate the usefulness of thoracic computed tomography (CT) after placement of an endovascular stent-graft for the treatment of descending thoracic aortic aneurysm.From 1992 to 1996, 85 patients with thoracic aortic aneurysm underwent stent-graft placement. In 63 patients, thoracic CT scans were obtained both before and within 10 days after placement. The CT findings were retrospectively studied, and their clinical effect analyzed. In 20 of 63 patients, long-term follow-up CT findings were also evaluated.After stent-graft placement in the 63 patients, CT demonstrated an increase in pleural effusion in 46 (73%), periaortic changes in 21 (33%), perigraft leak in 13 (21%), atelectasis in six (10%), mural thrombus within the stent-graft in two (3%), and new aortic dissection in one (2%). The mean maximum diameter of the aneurysm was 58.8 mm before and 60.0 mm after stent-graft insertion. Sixty-two (98%) patients were successfully treated until discharge. Interventional procedures were performed to eliminate the leakage into the aneurysm sac in 10 patients with perigraft flow depicted at CT. Other complications were managed conservatively.Thoracic CT is useful in the treatment of patients after stent-graft insertion for the management of descending thoracic aortic aneurysm.

    View details for Web of Science ID 000081086900027

    View details for PubMedID 10405738

  • Pelvic arterial embolization for control of obstetric hemorrhage: A five-year experience 66th Annual Meeting of the Central-Association-of-Obstetricians-and-Gynecologists Hansch, E., Chitkara, U., McAlpine, J., El-Sayed, Y., Dake, M. D., Razavi, M. K. MOSBY-ELSEVIER. 1999: 1454–60


    Obstetric hemorrhage is a significant cause of maternal morbidity and death. Postpartum hemorrhage that cannot be controlled by local measures has traditionally been managed by bilateral uterine artery or hypogastric artery ligation. These techniques have a high failure rate, often resulting in hysterectomy. In contrast, endovascular embolization techniques have a success rate of >90%. An additional benefit of the latter procedure is that fertility is maintained. We report our experience at Stanford University Medical Center in which this technique was used in 6 cases within the past 5 years.Six women between the ages of 18 and 41 years underwent placement of arterial catheters for emergency (n = 3) or prophylactic (n = 3) control of postpartum bleeding. Specific diagnoses included cervical pregnancy (n = 1), uterine atony (n = 3), and placenta previa and accreta (n = 2).Control of severe or anticipated postpartum hemorrhage was obtained with transcatheter embolization in 4 patients. A fifth patient had balloon occlusion of the uterine artery performed prophylactically, but embolization was not necessary. In a sixth case, bleeding could not be controlled in time, and hysterectomy was performed. The only complication observed with this technique was postpartum fever in 1 patient, which was treated with antibiotics and resolved within 7 days.Uterine artery embolization is a superior first-line alternative to surgery for control of obstetric hemorrhage. Use of transcatheter occlusion balloons before embolization allows timely control of bleeding and permits complete embolization of the uterine arteries and hemostasis. Given the improved ultrasonography techniques, diagnosis of some potential high-risk conditions for postpartum hemorrhage, such as placenta previa or accreta, can be made prenatally. The patient can then be prepared with prophylactic placement of arterial catheters, and rapid occlusion of these vessels can be achieved if necessary.

    View details for Web of Science ID 000081088200038

    View details for PubMedID 10368488

  • Thoracic aortic aneurysm repair with an endovascular stent graft: The "first generation" Aortic Surgery Symposium VI Mitchell, R. S., Miller, D. C., Dake, M. D., Semba, C. P., Moore, K. A., Sakai, T. ELSEVIER SCIENCE INC. 1999: 1971–74


    The feasibility and efficacy trial of an endovascular stent-grafting system for the treatment of aneurysms of the descending thoracic aorta was investigated.After Institutional Review Board approval, 103 patients (mean age 69 years) underwent stent graft repair of a descending thoracic aortic aneurysm between July 1992 and November 1997. The stent graft was fabricated using self-expanding "Z" stents covered by a woven Dacron tube graft. Follow-up, which averaged 22 months, was 100% complete. Simultaneous open abdominal aortic aneurysm repair was performed in 19 patients.Complete aneurysm thrombosis was achieved in 86 patients (83%). Early mortality, defined as a death during the same hospitalization or in less than 30 days, was 9 +/- 3%, and was significantly associated with preoperative cerebrovascular accident (CVA) or myocardial infarction. Major perioperative morbidity occurred in 31 patients, and included paraplegia in 3, CVA in 7, and respiratory insufficiency in 12 patients each. Actuarial survival was 81 +/- 4% at 1 year, and 73 +/- 5% at 2 years. Treatment failure (including all late, sudden, unexplained deaths) occurred in 38 patients, and only 53 +/- 10% of patients were free of treatment failure at 3.7 years. Five patients required late operative therapy for endoleaks associated with aneurysm enlargement.Satisfactory results were achieved using this "first-generation" homemade stent graft device. Mortality and morbidity occurred frequently, but may have been associated with the high-risk character of this patient population. Medium-term results were acceptable, but continued aortic enlargement, with the late development of endoleaks, is a significant concern. Second-generation devices with commercial development, coupled with this initial experience, should allow improved clinical results in the future. Longer term follow-up is still necessary to fully define the efficacy of this endovascular approach.

    View details for Web of Science ID 000081137800122

    View details for PubMedID 10391350

  • Percutaneous balloon fenestration and stenting for life-threatening ischemic complications in patients with acute aortic dissection 24th Annual Meeting of the Western-Thoracic-Surgical-Association Slonim, S. M., Miller, D. C., Mitchell, R. S., Semba, C. P., Razavi, M. K., Dake, M. D. MOSBY-ELSEVIER. 1999: 1118–26


    Acute aortic dissection frequently causes life-threatening ischemia of end-organs, historically associated with mortality exceeding 60%. Reperfusion with the use of interventional radiologic methods has evolved as a promising treatment. We report results of our initial 6 years of experience with percutaneous balloon fenestration of the intimal flap and endovascular stenting.Forty patients (32 male and 8 female) with a median age of 53 years (range 16-86 years) underwent percutaneous treatment for peripheral ischemic complications of 10 type A and 30 type B acute aortic dissections since 1991. Twenty patients had ischemia of multiple organ systems. Thirty patients had renal, 22 had leg, 18 had mesenteric, and 1 had arm ischemia.Fourteen patients were treated with stenting of either the true or false lumen combined with balloon fenestration of the intimal flap, 24 with stenting alone, and 2 with fenestration alone. Successful revascularization was achieved in 93% +/- 4% (+/-70% confidence levels) of patients (37/40). Nine patients had procedure-related complications. The 30-day mortality rate was 25% +/- 7% (10/40), often related to irreversible ischemia of intra-abdominal organs that was present before the procedure. Of the remaining 30 patients, 5 have died and the remaining 25 continue to have relief of ischemic symptoms at a mean follow-up of 29 months.Percutaneous balloon fenestration of the intimal flap and endovascular stenting is an effective treatment for life-threatening ischemic complications of acute aortic dissection.

    View details for Web of Science ID 000080866800010

    View details for PubMedID 10343260

  • Endovascular stent-graft placement for the treatment of acute aortic dissection NEW ENGLAND JOURNAL OF MEDICINE Dake, M. D., Kato, N., Mitchell, R. S., Semba, C. P., Razavi, M. K., Shimono, T., Hirano, T., Takeda, K., Yada, I., Miller, D. C. 1999; 340 (20): 1546-1552


    The standard treatment for acute aortic dissection is either surgical or medical therapy, depending on the morphologic features of the lesion and any associated complications. Irrespective of the form of treatment, the associated mortality and morbidity are considerable.We studied the placement of endovascular stent-grafts across the primary entry tear for the management of acute aortic dissection originating in the descending thoracic aorta. We evaluated the feasibility, safety, and effectiveness of transluminal stent-graft placement over the entry tear in 4 patients with acute type A aortic dissections (which involve the ascending aorta) and 15 patients with acute type B aortic dissections (which are confined to the descending aorta). Dissections involved aortic branches in 14 of the 19 patients (74 percent), and symptomatic compromise of multiple branch vessels was observed in 7 patients (37 percent). The stent-grafts were made of self-expanding stainless-steel covered with woven polyester or polytetrafluoroethylene material.Placement of endovascular stent-grafts across the primary entry tears was technically successful in all 19 patients. Complete thrombosis of the thoracic aortic false lumen was achieved in 15 patients (79 percent), and partial thrombosis was achieved in 4 (21 percent). Revascularization of ischemic branch vessels, with subsequent relief of corresponding symptoms, occurred in 76 percent of the obstructed branches. Three of the 19 patients died within 30 days, for an early mortality rate of 16 percent (95 percent confidence interval, 0 to 32 percent). There were no deaths and no instances of aneurysm or aortic rupture during the subsequent average follow-up period of 13 months.These initial results suggest that stent-graft coverage of the primary entry tear may be a promising new treatment for selected patients with acute aortic dissection. This technique requires further evaluation, however, to assess its therapeutic potential fully.

    View details for Web of Science ID 000080358900004

    View details for PubMedID 10332016

  • 1999 Gary J. Becker Young Investigator Award. MR-guided transjugular portosystemic shunt placement in a swine model. Journal of vascular and interventional radiology Kee, S. T., Rhee, J. S., Butts, K., Daniel, B., Pauly, J., Kerr, A., O'Sullivan, G. J., Sze, D. Y., Razavi, M. K., Semba, C. P., Herfkens, R. J., Dake, M. D. 1999; 10 (5): 529-535


    To evaluate the performance of portal venous puncture with use of magnetic resonance (MR) guidance, and to place a transjugular intrahepatic portosystemic shunt (TIPS) in a swine model.A study of 12 swine was performed to evaluate the ability of interventional MR imaging to guide portal vein puncture and TIPS placement. Six swine had catheters placed in the right hepatic vein under C-arm fluoroscopy. A nitinol guide wire was left in the vein and the animals were then moved into an open configuration MR imaging unit. A TIPS needle set was used to puncture the portal vein using MR fluoroscopy. The animals were transferred to the C-arm, and venography confirmed portal vein puncture. A follow-up study was performed in six additional swine to place a TIPS using only MR imaging guidance. MR tracking was used to advance a catheter from the right atrium into the inferior vena cava. Puncture of the portal vein was performed and a nitinol stent was placed, bridging the hepatic parenchyma. MR venogram confirmed placement.Successful portal vein puncture was achieved in all animals. The number of punctures required decreased from 12 in the first animal to a single puncture in the last eight swine. A stent was successfully placed across the hepatic tract in all six swine.Real-time MR imaging proved to be a feasible method to guide portal vein puncture and TIPS placement in pigs.

    View details for PubMedID 10357476

  • Endografts for the treatment of descending thoracic aortic aneurysm: Results of the first 150 procedures Dake, M., Semba, C., Kee, S., Razavi, M., Slonim, S., Samuels, S., Sze, D., Mitchell, R., Miller, D. INT SOC ENDOVASCULAR SPECIALIST. 1999: 189–89
  • Results of a multicenter feasibility study of the hemobahn stent-graft, in iliofemoral occlusive disease Dake, M., Semba, C., Kee, S., Razavi, M., Slonim, S., Samuels, S., Sze, D. INT SOC ENDOVASCULAR SPECIALIST. 1999: 188–88
  • Histopathologic evaluation of an expanded polytetrafluoroethylene-nitinol stent endoprosthesis in canine iliofemoral arteries JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Virmani, R., Kolodgie, F. D., Dake, M. D., Silver, J. H., Jones, R. M., Jenkins, M., Gillespie, D. L. 1999; 10 (4): 445-456


    The authors assess a new ePTFE-nitinol stent for its long-term patency, healing, and properties of endothelialization.Adult greyhounds (n = 18) underwent bilateral iliofemoral placement of an endoprosthesis (Hemobahn) consisting of a nitinol stent lined with an ultrathin expanded polytetrafluoroethylene (ePTFE) material. Histologic and quantitative morphometric analyses were performed on devices explanted at 2 weeks and 1, 3, 6, and 12 months. The source of endothelialization was examined in four additional devices modified by sealing either the proximal and distal ends or the entire graft with poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), a nonporous laminate to prevent potential transgraft endothelial cell migration.Device patency assessed with both intravascular ultrasound and histologic study showed minimal arterial stenosis, irrespective of implant duration. The neointima at less than 3 months consisted of fibrin and inflammatory infiltrate; at later time points, it was composed of mostly smooth muscle cells. Flow surfaces were more than 75% endothelialized by 3 months, which was nearly complete by 6 months. Modified endoprostheses entirely enveloped with FEP resulted in endothelialization of only the proximal and distal ends; the middle regions showed nonocclusive thrombi. Conversely, devices wrapped proximally and distally showed nearly complete endothelialization.This ePTFE-nitinol endoprosthesis demonstrated long-term patency at up to 1 year after implantation and showed early and nearly complete endothelialization by 6 months. The design promoted rapid endothelialization of flow surfaces, particularly in the midregion of the device possibly by transgraft migration.

    View details for Web of Science ID 000079815600011

    View details for PubMedID 10229474

  • Custom-made stent-graft of polytetrafluoroethylene-covered wallstents: Technique and applications JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kato, N., Sze, D. Y., Semba, C. P., Razavi, M. K., Kee, S. T., Dake, M. D. 1999; 10 (1): 9-16

    View details for Web of Science ID 000078191100002

    View details for PubMedID 10872483

  • The "first generation" of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta 78th Annual Meeting of the American-Association-for-Thoracic-Surgery Dake, M. D., Miller, D. C., Mitchell, R. S., Semba, C. P., Moore, K. A., Sakai, T. MOSBY-ELSEVIER. 1998: 689–703


    Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta.Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional "open" surgical procedure.Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% +/- 3% (+/- 70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death (P = .001). Early serious complications included paraplegia in 3% +/- 2% and stroke in 7% +/- 3%. Actuarial survival estimates at 1 year and 2 years were 81% +/- 4% and 73% +/- 5% (+/- 1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death (P = .003). According to the intent-to-treat principle, "treatment failure" (including all late sudden unexplained deaths) occurred in 38 patients; 53% +/- 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors.This 5-year clinical trial involving use of a "first generation" device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future.

    View details for Web of Science ID 000076693300002

    View details for PubMedID 9806376

  • Percutaneous treatment of bronchial artery aneurysm with use of transcatheter coil embolization and thoracic aortic stent-graft placement JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sakai, T., Razavi, M. K., Semba, C. P., Kee, S. T., Sze, D. Y., Dake, M. D. 1998; 9 (6): 1025-1028

    View details for Web of Science ID 000077125300027

    View details for PubMedID 9840053

  • Endovascular stent-graft placement to obliterate the entry tear: A new treatment for acute aortic dissection Dake, M. D., Kato, N., Slonim, S. M., Razavi, M. K., Semba, C. P., Kee, S. T., Sze, D. Y., Samuels, S. L., Mitchell, R. S., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1998: 67–67
  • The stent decade: 1987 to 1997 AMERICAN HEART JOURNAL Oesterle, S. N., Whitbourn, R., Fitzgerald, P. J., Yeung, A. C., Stertzer, S. H., Dake, M. D., Yock, P. G., Virmani, R. 1998; 136 (4): 578-599


    In January 1997, experts from the United States, Europe, and Japan gathered at Stanford University to review their collective experience with intracoronary and noncoronary stenting and to identify and prioritize issues requiring further clinical investigation. This report summarizes the discussions that took place during this stent summit. Knowledge of stent-tissue interaction from animal and human pathologic specimens was reviewed in the context of evolving stent designs. The relative merits of coil and slotted tubular stent designs were discussed. Stent deployment routines, including self-expansion, balloon expansion, and high-pressure delivery were debated. The potential for covered stents and coated stents was explored. Problems surrounding the routine deployment of stents were identified: small vessel disease, long lesions, bifurcation stenoses, vein graft disease, ostial disease, left main stenoses, and intrastent restenosis. The value of intravascular ultrasound, as an adjunct to stenting, was explored and debated. An algorithm for "provisional stenting" based on ultrasound criteria was developed. Noncoronary stenting of the aorta, iliacs, and carotids were discussed. Clinical applications that may lead to randomized clinical trials were identified.

    View details for Web of Science ID 000076316800005

    View details for PubMedID 9778060

  • 1998 ARRS President's Award. The potential of in vivo vascular tissue engineering for the treatment of vascular thrombosis: a preliminary report. American Roentgen Ray Society. AJR. American journal of roentgenology Kuo, M. D., Waugh, J. M., Yuksel, E., Weinfeld, A. B., Yuksel, M., Dake, M. D. 1998; 171 (3): 553-558


    Current gene therapy and tissue engineering protocols suffer from a number of inherent limitations. In this study, we examine the feasibility of a new approach for the treatment of vascular thrombosis: in vivo tissue engineering.Rabbit femoral veins were transfected in situ with either a previously characterized adenoviral-construct-expressing tissue plasminogen activator or a viral (adenoviral-construct-expressing beta-galactosidase) or nonviral (buffer) control and used as cross sections (n = 3). Treated veins were then harvested and grafted into the ipsilateral common femoral artery as an interposition vein graft. A potent stimulus for thrombus formation was then introduced into the recipient artery downstream of the graft. Six days later, the rabbits were sacrificed, and the grafts and downstream arteries were harvested. Vessel segments were then examined for thrombus according to defined anatomic zones. Transfection efficiency and presence of smooth muscle cells in the vein graft were also evaluated.The engineered vein graft showed a significant reduction in thrombus formation within both the graft and the downstream artery relative to nonviral (buffer) and viral (adenoviral-Rous sarcoma virus beta-galactosidase [Adv/RSV-betagal]) controls. Underlying endothelial cell transfection efficiency of 90% was observed in viral controls (Adv/RSV-betagal). A 2.4-fold increase in smooth muscle alpha-actin positive cells in the engineered vein graft was seen compared with nonviral (phosphate-buffered saline) controls. A 10-fold increase in smooth muscle alpha-actin-positive cells in the engineered vein graft relative to viral (Adv/RSV-betagal) controls was also observed.In vivo tissue engineering is a new paradigm in molecular medicine that is a viable alternative to conventional gene therapy and tissue engineering for the treatment of vascular thrombosis.

    View details for PubMedID 9725272

  • Aneurysm of an aberrant right subclavian artery: Treatment with PTFE covered stentgraft JOURNAL OF VASCULAR SURGERY Davidian, M., Kee, S. T., Kato, N., Semba, C. P., Razavi, M. K., Mitchell, R. S., Dake, M. D. 1998; 28 (2): 335-339

    View details for Web of Science ID 000075344600021

    View details for PubMedID 9719329

  • Superior vena cava syndrome after heart transplantation: Percutaneous treatment of a complication of bicaval anastomoses JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sze, D. Y., Robbins, R. C., Semba, C. P., Razavi, M. K., Dake, M. D. 1998; 116 (2): 253-261


    Our objectives were (1) to investigate the incidence and cause of symptomatic superior vena caval anastomotic stenosis and central venous thrombosis in patients receiving heart or heart-lung transplantation and (2) to explore percutaneous methods of thrombolysis and endoluminal intervention to treat these complications.Review of 1016 cases revealed three cases of superior vena cava syndrome. Anatomy, surgical technique, and medical risk factors were examined. Percutaneous treatments, including urokinase thrombolysis, mechanical thrombolysis, balloon angioplasty, and stent placement, were attempted.All three of these patients underwent transplantation by means of the bicaval anastomotic technique. In addition, the diameters of the donor and recipient cavae were grossly mismatched in all three. Stenoses in all three patients were successfully treated percutaneously with balloon angioplasty and stent placement. Treatment of the accompanying large-volume thrombosis was problematic in these patients, and two had hemorrhagic complications of urokinase thrombolysis. A mechanical thrombolysis device was used successfully in the third patient.Anastomotic stricture and central venous thrombosis is an uncommon complication of the bicaval anastomotic technique of heart and heart-lung transplantation. Discrepancy between donor and recipient caval diameters appears to be the major risk factor. Endoluminal thrombolysis and stenting provides rapid and enduring relief of symptoms and precludes repeat sternotomy, cardiopulmonary bypass, and general anesthesia.

    View details for Web of Science ID 000075104300011

    View details for PubMedID 9699577

  • Percutaneous creation of acute type-B aortic dissection: An experimental model for endoluminal therapy JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Razavi, M. K., Nishimura, E., Slonim, S., Zeigler, W., Kee, S., Witherall, H. L., Semba, C. P., Dake, M. D. 1998; 9 (4): 626-632


    To evaluate the feasibility of a percutaneously created type-B aortic dissection as an experimental model for percutaneous therapy. This model was used to evaluate the hemodynamic effects of single-balloon fenestration of the intimal flap.Acute type-B dissections were created in descending aortae of 15 swine via a femoral (n = 6) or carotid (n = 9) approach. The initial subintimal tear was made with use of a Colapinto needle. The dissections were extended to a predefined position in the aorta. The proximal and distal tears were balloon dilated. The mural flap was balloon fenestrated in six animals, just above the celiac artery. Aortograms were obtained to establish the presence and extent of the dissection. Manometry was performed in both lumina to evaluate the hemodynamics of the dissected aorta and the effects of balloon fenestration in this model. Pathologic specimens were also examined.Creation of dissection was successful in 11 of 15 animals, with six developing true lumen narrowing (group A). The other five animals (group B) had flow in both lumina without evidence of true lumen narrowing. After the creation of a single-balloon fenestration in the group A swine, the arteriograms revealed no evidence of blood admixture between the true and false lumina, and there was no change in the intravascular pressures. Examination of the explanted aortae showed a more extensive circumferential dissection in group A animals as compared with group B.The percutaneously created acute type-B aortic dissection is a feasible model for experimentation. The hemodynamics of the aorta did not change after single-balloon fenestration in this model.

    View details for Web of Science ID 000074791200015

    View details for PubMedID 9684834

  • Applications of spiral CT in endovascular aortic interventions SEMINARS IN INTERVENTIONAL RADIOLOGY Semba, C. P., Razavi, M. K., Kee, S. T., Dake, M. D. 1998; 15 (2): 179-187
  • Stents match surgery in treating aortic aneurysms. Diagnostic imaging Razavi, M., Semba, C., Dake, M. 1998; 20 (3): 54-56

    View details for PubMedID 10177660

  • Stent-graft treatment in diseases of the thoracic aorta SEMINARS IN INTERVENTIONAL RADIOLOGY Kato, N., Dake, M. D., Semba, C. P., Razavi, M. K., Kee, S. T., Slonim, S. M., Samuels, S. L. 1998; 15 (1): 21-28
  • Mycotic aneurysms of the thoracic aorta: Repair with use of endovascular stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Sakai, T., Slonim, S. M., Razavi, M. K., Kee, S. T., Jorgensen, M. J., Hagberg, R. C., Lee, G. K., Mitchell, R. S., Miller, D. C., Dake, M. D. 1998; 9 (1): 33-40


    Standard therapy of mycotic aneurysms in the descending aorta consists of thoracotomy and in situ graft placement or extraanatomic bypass. The alternative use of endovascular stent-grafts was evaluated for management of infected aneurysms of the thoracic aorta.In a retrospective analysis during a 5-year period, 112 patients underwent stent-graft placement for thoracic aortic aneurysms. Three patients (mean age, 68.6; range, 64-70 years) had mycotic thoracic aneurysms. Stent-grafts were constructed from Z stents covered with polyester fabric and were delivered remotely through a catheter under fluoroscopic guidance.Complete thrombosis of the mycotic aneurysms was achieved in all patients. One patient required a second separate stent-graft placement procedure because of migration of the initial device; the second patient underwent surgical repair of a ruptured mycotic abdominal aortic aneurysm followed immediately by stent-graft placement for a chronic mycotic thoracic aneurysm; a third patient underwent repair of two infected false aneurysms secondary to complete rupture of a surgical interposition graft. There were no complications of persistent bacteremia despite placement of the stent-graft device at the site of primary infection, reinfection, delayed rupture, paraplegia, distal emboli, or surgical conversion. One patient died of cardiac arrest at 25 months; there were no perioperative deaths (< or = 30 days). The remaining two patients were alive and well at median follow-up of 24 months (range, 4-25 months).Endovascular stent-grafts combined with antibiotic therapy may be an alternative to conventional thoracotomy in managing mycotic aneurysms of the descending thoracic aorta.

    View details for Web of Science ID 000071543100005

    View details for PubMedID 9468393

  • Superior vena cava syndrome: Treatment with catheter-directed thrombolysis and endovascular stent placement RADIOLOGY Kee, S. T., Kinoshita, L., Razavi, M. K., Nyman, U. R., Semba, C. P., Dake, M. D. 1998; 206 (1): 187-193


    To evaluate use of catheter-directed thrombolysis and/or endovascular stent placement to treat superior vena cava (SVC) syndrome.Fifty-nine consecutive patients with SVC syndrome were studied. The cause was underlying malignancy in 43 and benign disease in 16. All patients underwent bilateral upper-extremity venography. The SVC was occluded in 31 cases and stenosed in 28. Twenty-seven patients underwent catheter-directed thrombolysis; 51 underwent endovascular stent placement. Patency was defined in terms of absence of symptoms and signs of SVC syndrome.Technical success was achieved in 56 of 59 patients (95%). Among 42 patients with underlying malignancy (mean follow-up, 7.0 months; range, 1-34 months), primary clinical patency was achieved in 33 (79%) and secondary clinical patency was achieved in 39 (93%). Among 13 patients with benign disease (mean follow-up, 17.0 months; range, 1-27 months), primary clinical patency was achieved in 10 (77%) and secondary clinical patency was achieved in 11 (85%). Four patients were lost to follow-up. Periprocedural mortality and morbidity rates were 3% (two of 59 patients) and 10% (six of 59 patients), respectively.Catheter-directed thrombolysis and endovascular stent placement is a safe and effective treatment for SVC syndrome.

    View details for Web of Science ID 000071093500034

    View details for PubMedID 9423671

  • Transbronchial Palmaz stent placement for tracheo-bronchial stenosis JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Slonim, S. M., Razavi, M., Kee, S., Semba, C. P., Drake, M. D. 1998; 9 (1): 153-160


    Evaluation of the efficacy of transbronchial Palmaz stent placement in the treatment of tracheo-bronchial narrowing.Twelve patients with stenoses of the tracheo-bronchial tree were treated with balloon-expandable Palmaz stents. Etiology was anastomotic stenosis after lung transplantation (n = 3), bronchogenic carcinoma (n = 2), external compression from thoracic aortic aneurysm (n = 2), Mycobacterium tuberculosis (n = 1), esophageal carcinoma (n = 1), after lobectomy (n = 1), after lobectomy and endobronchial radiation (n = 1), and lye ingestion (n = 1). All patients had respiratory symptoms, radiologic findings of persistent atelectasis, or worsening pulmonary function tests. Bronchoscopy was used to delineate the stenosis prior to intervention. With use of fluoroscopic guidance, stents were placed in the mainstem bronchus (n = 11), lower lobe bronchus (n = 5), bronchus intermedius (n = 5), trachea (n = 3), and middle lobe bronchus (n = 1).Initial technical success was achieved in all patients. Ten of the 12 patients (83%) had improvement of clinical pulmonary signs or symptoms. During follow-up, five patients died. One was lost to follow-up and was presumed dead. The 30-day mortality rate was 17% (two of 12 patients). The two complications were superficial laceration of the bronchial mucosa during balloon dilation in one patient and compression of stents by a thoracic aortic aneurysm in another patient.Initial results suggest that transbronchial Palmaz stent placement is a feasible and effective method of treating tracheo-bronchial stenosis.

    View details for Web of Science ID 000071543100023

    View details for PubMedID 9468411

  • Treatment of aortoiliac aneurysms with use of single-piece tapered stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kato, N., Dake, M. D., Semba, C. P., Razavi, M. K., Kee, S. T., Slonim, S. M., Samuels, S. L., Terasaki, K. K., Zarins, C. K., Mitchell, R. S., Miller, D. C. 1998; 9 (1): 41-49


    The authors describe their experience with the use of single-piece, tapered stent-grafts for the treatment of abdominal aortic or aortoiliac aneurysms.Single-piece, tapered stent-grafts were placed in 15 patients for the treatment of abdominal aortic aneurysms with small distal necks (n = 13), and aortoiliac aneurysms (n = 2). There were 13 men and two women who ranged in age from 59 to 83 years (mean, 71 years). Usual open surgery was considered high risk in all patients because of comorbid medical conditions. The stent-grafts were made of Z stents covered with polytetrafluoroethylene (PTFE). Additional stent-grafts needed to treat perigraft leaks were made of Z stents covered with woven polyester (n = 5), Wallstents covered with PTFE (n = 2), Z stents covered with PTFE (n = 1), and a PTFE-covered Palmaz stent (n = 1). After stent-graft placement, the contralateral iliac artery was occluded by a blocking device composed of either a PTFE-covered Palmaz (n = 1) or Z stent (n = 13), and a femoral-femoral bypass was created.After placement of the stent-grafts, immediate perigraft leaks were observed in eight patients (53%). These were at the proximal (n = 5) or the distal end (n = 3). All, except one, were treated successfully with additional stent-grafts. The one failure was in a patient who developed aortic rupture after balloon dilation, requiring open surgical repair. Second procedures were required in four patients (27%), including three leaks treated successfully with coil embolization and/or a back-up stent-graft, and one stent-graft migration and thrombosis treated by thrombolysis and placement of an additional stent-graft. One patient died of respiratory failure 23 days after placement of the stent-graft. The mean follow-up was 12 months (range, 4-26 months). On the last follow-up, the aneurysms in the 13 living patients remained thrombosed.Treatment of aortoiliac aneurysms with use of single-piece, tapered stent-grafts is feasible in selected patients. The morbidity and mortality rates compare favorably with those of the open surgical procedures in a high-risk population. Further improvements in the technique and longer follow-up data are needed before this procedure can be recommended for the treatment of all aortoiliac aneurysms.

    View details for Web of Science ID 000071543100006

    View details for PubMedID 9468394

  • Stent-graft repair of thoracic aortic aneurysms. Seminars in vascular surgery Mitchell, R. S., Miller, D. C., Dake, M. D. 1997; 10 (4): 257-271


    Aneurysmal disease of the thoracic aorta continues to be a very challenging management problem for physicians because of the many comorbidities harbored by these patients, as well as the morbidity of the conventional open repair via left thoracotomy. In a combined effort between interventional radiology and cardiovascular surgery, an endovascular stent graft repair has been devised for these patients in an effort to reduce morbidity. This report documents the results in the first 108 patients so treated. The graft itself, custom-made for each individual, is composed of interlocked, self-expanding "Z" stents covered with a woven Dacron graft. Compressed in a loading capsule, the graft can then be advanced through a 27-French (outside diameter; OD) sheath, which is positioned within the aneurysm under fluoroscopic guidance. Relatively normal 2- to 3-cm segments of proximal and distal aorta allow an adequate friction seal to prevent stent graft dislodgement and also provide a hemostatic seal to obliterate aneurysm filling. Complete aneurysm thrombosis was achieved primarily in 103 patients. There were 10 deaths (9.25%) within the first 30 days, four of which were directly attributable to the stent graft procedure. Perioperative strokes occurred in four patients, and there were four instances of paraplegia. There have been two documented stent graft failures in a mean follow-up of 21.8 months (range, 1 to 57 months). Although the long-term durability of this procedure remains unknown, we believe this less invasive endovascular approach will prove to be an effective and less morbid treatment for aneurysmal disease of the descending thoracic aorta.

    View details for PubMedID 9431597

  • Traumatic thoracic aortic aneurysm: Treatment with endovascular stent-grafts RADIOLOGY Kato, N., Dake, M. D., Miller, D. C., Semba, C. P., Mitchell, R. S., Razavi, M. K., Kee, S. T. 1997; 205 (3): 657-662


    To demonstrate the feasibility and safety of endovascular stent-graft placement for treatment of traumatic aortic aneurysm.Ten patients with traumatic aortic aneurysm were treated with endovascular stent-grafts. Three patients had an acute traumatic aneurysm; seven had a chronic aneurysm. Stent-grafts were constructed from modified Z-stents covered with woven polyester or expanded polytetrafluoroethylene graft material and were deployed through a 20-24-F delivery sheath in an exposed artery located remotely from the lesion.Stent-graft placement and thrombosis of the aneurysmal sac were successful in all patients. Major complications were encountered in three patients after endovascular treatment. One patient had a peri-graft leak; complete thrombosis of the aneurysmal sac was achieved after coil embolization of the leak. Transposition of the left subclavian artery was necessary to relieve left arm ischemia in another patient. In the third patient, stent placement in the left main stem bronchus was needed to relieve left lung atelectasis. All patients were alive and without complications during the follow-up period (mean, 15 months).Transluminal placement of endovascular stent-grafts is a technically feasible method for treatment of traumatic thoracic aortic aneurysm and may be an effective alternative to open-chest surgery.

    View details for Web of Science ID A1997YG85000007

    View details for PubMedID 9393517

  • Treatment of peripheral vascular disease with stent-grafts RADIOLOGY Cragg, A. H., Dake, M. D. 1997; 205 (2): 307-314

    View details for Web of Science ID A1997YD15100004

    View details for PubMedID 9356607

  • Transjugular intrahepatic portosystemic shunt placement in a child complicated by perforated Roux-en-Y portoenterostomy JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION Wang, J., Cox, K. L., Dake, M., Esquivel, C. O., So, S. K. 1997; 25 (4): 421-425

    View details for Web of Science ID A1997XY50500011

    View details for PubMedID 9327374

  • Guidelines regarding HIV and other bloodborne pathogens in vascular/interventional radiology JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Hansen, M. E., Bakal, C. W., Dixon, G. D., Eschelman, D. J., Horton, K. M., Katz, M., Olcott, E. W., Sacks, D., Becker, G. J., Burke, D. R., Cole, P. E., Dake, M. D., Gray, R. J., Haskal, Z. J., Holden, R. W., Machan, L. S., Patel, N. H., SHLANSKYGOLDBERG, R. 1997; 8 (4): 667-676
  • Acute rupture of the descending thoracic aorta: Repair with use of endovascular stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Kato, N., Kee, S. T., Lee, G. K., Mitchell, R. S., Miller, D. C., Dake, M. D. 1997; 8 (3): 337-342


    To describe the use of endovascular stent-grafts to treat acute ruptures of the descending thoracic aorta as an alternative to surgery in high-risk patients.From July 1992 to August 1996, 95 patients underwent stent-grafting of the descending thoracic aorta for a variety of lesions. Of these, 11 patients with acute (< or = 7 days) rupture from aneurysms (n = 8) or trauma (n = 3) underwent repair with use of endovascular stent-grafts. Rupture was confirmed with preoperative imaging studies and occurred in the mediastinum (n = 9), the pleural space (n = 1), or the lung (n = 1). All patients were considered high surgical risk due to generalized cardiopulmonary disease and/or previous thoracotomies. Stent-grafts were constructed from Z stents covered with polyester fabric and delivered through a catheter under fluoroscopic control from a remote access site.Stent-graft deployment was successful in all patients. There were no complications of perigraft leak, stent migration, paraplegia, or intraoperative death. Two patients died in the follow-up period: one of ventricular perforation during unrelated thoracic surgery for tumor resection (day 1) and one of cardiac arrest (day 28). All others are alive (mean follow-up, 15.1 months).For acute rupture of the thoracic aorta, endovascular stent-graft repair is technically feasible and may be a therapeutic alternative to a surgical interposition graft in patients considered high risk for conventional thoracotomy. Long-term studies are necessary to determine the role of stent-grafts in preventing future aortic rupture.

    View details for Web of Science ID A1997WY51200004

    View details for PubMedID 9152904

  • Covered stent placement for neurovascular disease AMERICAN JOURNAL OF NEURORADIOLOGY Singer, R. J., Dake, M. D., Norbash, A., Abe, T., Marcellus, M. L., Marks, M. P. 1997; 18 (3): 507-509


    We describe an endovascular technique in which covered stents were used to occlude a parent vessel. In one patient, with a giant paraclinoid aneurysm, a Gortex-covered Palmaz stent was used to occlude the cervical internal carotid artery and to create thrombosis in the aneurysm. In the second patient, with a high-flow vertebrojugular fistula, a hooded stent provided definitive treatment after an attempt to close the fistula by detachable balloon therapy failed. Follow-up of these patients revealed stable stent position and no untoward effects of permanent vessel occlusion.

    View details for Web of Science ID A1997WQ52300019

    View details for PubMedID 9090412

  • Simultaneous abdominal aortic replacement and thoracic stent-graft placement for multilevel aortic disease Joint Annual Meeting of the Society-for-Vascular-Surgery and the North-American-Chapter of the International-Society-for-Cardiovascular-Surgery Moon, M. R., Mitchell, R. S., Dake, M. D., Zarins, C. K., Fann, J. I., Miller, D. C. MOSBY-YEAR BOOK INC. 1997: 332–40


    Patients with aneurysmal disease involving both the descending thoracic and abdominal aorta have historically required simultaneous or sequential conventional operations, but the morbidity rate is high with either approach in these patients, who often exhibit coexisting cardiopulmonary disease. Transluminally placed endovascular grafts have recently been developed for repair of aortic aneurysms, and we have implemented these techniques to eliminate the need for a thoracotomy in patients with multilevel aortic disease.Since January 1994, 18 patients have undergone conventional abdominal aortic replacement with endovascular stent-graft placement into the descending thoracic aorta under fluoroscopic guidance through a 10 mm Dacron side limb off the abdominal graft. Abdominal aortic replacement required a tube graft in eight patients and bifurcated grafts in 10 patients. Thoracic stent-grafts (custom fabricated, woven Dacron covered, self-expandable stents) averaged 12.2 +/- 4.2 cm (mean +/- SD) in length.One patient died, resulting in a hospital mortality rate of 6%. No patients required further surgical intervention to treat their aortic disease. Seventeen patients (94%) are currently well 14 +/- 8 months after surgery (range, 3 to 29 months) with completely excluded thoracic aortic disease, no stent migration, and no change in stent configuration documented by serial radiologic examinations.Simultaneous abdominal aortic replacement and deployment of a thoracic stent-graft can safely exclude multilevel aortic aneurysmal disease and may be a valuable treatment option for these otherwise high-risk patients.

    View details for Web of Science ID A1997WL46300024

    View details for PubMedID 9052568

  • Use of a self-expanding vascular occluder for embolization during endovascular aortic aneurysm repair JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kato, N., Semba, C. P., Dake, M. D. 1997; 8 (1): 27-33


    Repair of aortic aneurysms with use of stent-graft techniques may require occlusion of large branch vessels to prevent back-bleeding into the excluded aneurysmal sac. The authors describe their experience using a self-expanding vascular occluder (SEVO) to occlude flow in branch arteries during aortic stent-grafting.Eighty-four patients (65 men, 19 women; mean age, 64 years) underwent thoracic (n = 72) or abdominal aortic (n = 12) stent-grafting. Aneurysm repair was performed using nonbifurcated Z stents covered with polyester or polytetrafluoroethylene (PTFE) fabric. SEVOs constructed from a Z stent (10-20 mm diameter) and PTFE were deployed through a separate catheter (14-20 F).Ten of 84 patients required embolization of large branch arteries with use of a SEVO during aortic stent-grafting (thoracic, n = 1; abdominal, n = 9). The SEVO was placed in the common iliac (n = 9) or subclavian artery (n = 1). The mean SEVO diameter was 14.7 mm (range, 10-20 mm). Eight patients undergoing SEVO embolization had immediate thrombosis of the treated artery. One patient required additional embolization with use of conventional coils. No patients had back-bleeding into the aneurysm, device migration, microembolization, or limb ischemia (mean follow-up, 140 days; range, 50-200). All 10 patients had complete thrombosis of the aortic aneurysm.Use of a novel self-expanding vascular occluding device is a safe and effective supplementary technique to occlude high-flow, large-diameter arterial branch vessels during endovascular aortic aneurysm repair.

    View details for Web of Science ID A1997WR45900005

    View details for PubMedID 9025035

  • Reporting standards for clinical evaluation of new peripheral arterial revascularization devices JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sacks, D., MARINELLI, D. L., Martin, L. G., Spies, J. B., Bakal, C. W., Becker, G. J., Burke, D. R., Cole, P. E., Dake, M. D., Gray, M. J., Hansen, M. E., Haskal, Z. J., Holden, R. W., Katz, M. D., Machan, L. S., Patel, N. H., SHLANSKYGOLDBERG, R. 1997; 8 (1): 137-149
  • General principles for evaluation of new interventional technologies and devices JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sacks, D., MARINELLI, D. L., Martin, L. G., Spies, J. B., Bakal, C. W., Becker, G. J., Burke, D. R., Cole, P. E., Dake, M. D., Gray, R. J., Hansen, M. E., Haskal, Z. J., Holden, R. W., Katz, M. D., Machan, L. S., Patel, N. H., SHLANSKYGOLDBERG, R. 1997; 8 (1): 133-136
  • Thoracic aortic aneurysm repair with endovascular stent-grafts. Vascular medicine Semba, C. P., Mitchell, R. S., Miller, D. C., Kato, N., Kee, S. T., Chen, J. T., Dake, M. D. 1997; 2 (2): 98-103


    The purpose of the study was to describe the clinical experience is using endoluminal stent-grafts for the treatment of thoracic aortic aneurysms in high-risk patients. Patients with aneurysms of the descending thoracic aorta who were considered high surgical risks underwent evaluation for endoluminal repair. The prosthesis was constructed from Z stents covered with polyester fabric using dimensions based upon preprocedural computed tomography scans and angiography. Through a femoral arteriotomy or left retroperitoneal flank incision, a 22-24 Fr delivery catheter was inserted and advanced through the aorta to the target site under fluoroscopic guidance in the operating suite. The stent-graft prosthesis was deployed at the site of the aneurysm. 44 patients (36 male, 8 female; mean age 36 years) underwent stent-graft repair for thoracic aneurysms (mean diameter 6.3 cm). The deployment was technically successful in all cases, with complete aneurysm thrombosis in 88%. The 30-day perioperative mortality rate was 6.8% and 35-month actuarial survival was 82%. There were no cases of stent migration, surgical conversion or intraprocedural death. Paraplegia occurred in two patients who underwent simultaneous surgical infrarenal aortic aneurysm repair immediately followed by stent-graft placement for a coexisting thoracic aneurysm. The conclusion was that placement of endoluminal stent-grafts for repair of thoracic aortic aneurysms is technically feasible in high-risk patients in whom conventional surgery is contraindicated. Long-term studies are needed to determine protection against aneurysm rupture and patient survival.

    View details for PubMedID 9546963

  • Endovascular stenting of an aortopulmonary fistula presenting with hemoptysis - A case report JOURNAL OF CARDIOVASCULAR SURGERY Campagna, A. C., Wehner, J. H., Kirsch, C. M., Semba, C. P., Kagawa, F. T., Jensen, W. A., Dake, M. D. 1996; 37 (6): 643-646


    We present a 45 year old man with massive hemoptysis due to an aortopulmonary fistula. Our patient had a history of a previous patent ductus arteriosus repair which was complicated by a previous aortopulmonary fistula. Computed tomography of the chest and aortography made the diagnosis of a recurrent aortopulmonary fistula. Because of the history of previous surgical aortic procedures, repair of the fistula was completed through a retroperitoneal aortotomy with intravascular insertion of an expandable stainless steel stent covered by a polyester graft. The patient has had no hemoptysis or computed tomographic evidence of fistula recurrence thirty eight months after the procedure.

    View details for Web of Science ID A1996WF14800022

    View details for PubMedID 9016985

  • Embolization of backbleeding lumbar arteries filling an aortic aneurysm sac after endovascular stent-graft placement JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Khilnani, N. M., Sos, T. A., Trost, D. W., Winchester, P. A., Jagust, M. B., Mitchell, R. S., Dake, M. D. 1996; 7 (6): 813-817

    View details for Web of Science ID A1996WJ72700003

    View details for PubMedID 8951747

  • Embolization of perigraft leaks after endovascular stent-graft treatment of aortic aneurysms JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kato, N., Semba, C. P., Dake, M. D. 1996; 7 (6): 805-811


    Perigraft leak is one of the significant problems associated with transluminal placement of stent-grafts in the treatment of aortic aneurysms. This report describes the authors' experience with transcatheter coil embolization for the treatment of perigraft leaks.Ten patients who underwent transluminal placement of stent-grafts for the treatment of aortic aneurysms were treated. All patients had one or more tracts between the aortic wall and stent-graft or between two stent-grafts, resulting in residual aneurysm filling. All tracts were embolized by means of transcatheter deposition of platinum or steel coils.In all patients, all tracts were embolized completely and residual aneurysm filling was eliminated. Complete thrombosis of the aneurysm was confined on follow-up spiral computed tomography in all 10 cases. Two cases required two embolization procedures to completely embolize the tracts. No recurrent leaks or aneurysm expansions were identified on follow-up studies.Although long-term effectiveness remains to be proved, the initial results with transcatheter coil embolization of tracts are encouraging and suggest this technique is a safe and effective method for the management of perigraft leaks after endovascular placement of stent-grafts.

    View details for Web of Science ID A1996WJ72700002

    View details for PubMedID 8951746

  • True lumen obliteration in complicated aortic dissection: Endovascular treatment 1995 Annual Meeting of the Radiological-Society-of-North-America Slonim, S. M., NYMAN, U. R., Semba, C. P., Miller, D. C., Mitchell, R. S., Dake, M. D. RADIOLOGICAL SOC NORTH AMER. 1996: 161–66


    To evaluate endovascular treatment of ischemic complications caused by true lumen obliteration in aortic dissection.Endovascular techniques were used to treat true lumen obliteration in 11 patients with complicated aortic dissection. In all cases, the true lumen was compressed to a paper-thin sliver by the expanded false lumen. Two patients had Stanford type A (chronic) and nine had type B (six acute, three chronic) dissections. Obliteration of the true lumen was associated with branch vessel ischemia that included renal (n = 7), mesenteric (n = 6), and lower-extremity (n = 6) arterial compromise. Two patients were treated with aortic stents, four with balloon fenestration of the intimal flap, and three with both stent placement and fenestration. In two patients, ischemic complications caused by true lumen obliteration could not be treated with endovascular techniques.Revascularization was technically successful with relief of clinical symptoms in nine patients. Revascularization was unsuccessful in one patient in whom surgical revascularization of the superior mesenteric artery was necessary and in one in whom hypertension was managed medically. One patient developed thrombosis of a renal artery in which a stent had been placed. The 30-day mortality rate was 9%, and the mean follow-up was 10.1 months (range, 2 weeks to 39 months).True lumen obliteration can be safely and effectively treated with endovascular stent placement and balloon fenestration.

    View details for Web of Science ID A1996VJ11400034

    View details for PubMedID 8816538

  • Percutaneous creation of a mesocaval shunt JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Nyman, U. R., Semba, C. P., Chang, H., HOFFMAN, C., Dake, M. D. 1996; 7 (5): 769-773

    View details for Web of Science ID A1996VM63100026

    View details for PubMedID 8897349

  • [Local thrombolysis and stents in deep venous thrombosis. A new endovascular therapeutic technique]. Läkartidningen Nyman, U., Semba, C. P., Dake, M. D., Ivancev, K., Lindh, M. 1996; 93 (32-33): 2750-2756

    View details for PubMedID 8765598

  • Vertebral artery stenting following percutaneous transluminal angioplasty - Technical note JOURNAL OF NEUROSURGERY Storey, G. S., Marks, M. P., Dake, M., Norbash, A. M., Steinberg, G. K. 1996; 84 (5): 883-887


    The authors report initial results and follow up using stent placement to treat atherosclerotic stenosis in vertebral arteries. Three patients with severe atherosclerotic vascular disease underwent vertebral artery stent placement using a balloon expandable stent. Medical therapy (aspirin and warfarin) and conventional percutaneous angioplasty failed to resolve the disease and the patients developed symptomatic restenosis within 3 months of angioplasty. Two patients had symptoms of anterior circulation ischemia with carotid artery occlusions and reduced supply to the anterior circulation from the stenosed vertebral arteries. One patient had recurrent posterior circulation symptoms. Stents were successfully placed in all three, resulting in immediate reversal of stenosis and resolution of symptoms. Clinical follow-up study (mean 9 months) has shown no recurrent symptoms in the patient with posterior circulation symptoms, but the two patients with anterior circulation ischemia did develop recurrent symptoms. Angiographic follow up in these two patients at 3 months and 1 year, however, demonstrated continued patency of vertebral artery lumina. They underwent extracranial-intracranial bypass surgery to relieve their symptoms. This experience suggests stents can be placed without complication in the proximal vertebral arteries and may have an adjunctive role in the treatment of atherosclerotic cerebrovascular disease following unsuccessful angioplasty.

    View details for Web of Science ID A1996UG54000028

    View details for PubMedID 8622166

  • Endovascular stent-graft repair of thoracic aortic aneurysms 21st Annual Meeting of the Western-Thoracic-Surgical-Association Mitchell, R. S., Dake, M. D., Semba, C. P., Fogarty, T. J., Zarins, C. K., Liddell, R. P., Miller, D. C. MOSBY-YEAR BOOK INC. 1996: 1054–60


    Conventional repair of aneurysms of the descending thoracic aorta entails thoracotomy and graft interposition. For elderly patients and those with previous operations, obesity, respiratory insufficiency, or other comorbidities, such a procedure entails significant mortality and morbidity. Transluminal stent-graft placement offers an alternative approach with potentially less morbidity and quicker recovery; however, the effectiveness and durability of stent-grafts remain uncertain.Since July 1992, thoracic aortic stent-grafts have been placed in 44 patients with a variety of pathologic conditions. Each graft was individually constructed from self- expanding, stainless-steel Z stents covered with a woven Dacron polyester fabric graft. Craft dimensions were determined from spiral computed tomographic scans. All implants were performed in the operating theater under fluoroscopic and transesophageal echocardiographic guidance. Follow-up was by computed tomography and contrast angiography in all cases. PATIENT DATA: There were 36 men and 8 women. Mean age was 66 years (range 35 to 88 years). Mean aneurysmal diameter was 6.3 cm (range 4.0 to 9.4 cm). Etiologies included 23 degenerative aneurysms, four posttraumatic aneurysms, four pseudoaneurysms, and one chronic aortic dissection.There were three early deaths (<30 days) and two late deaths. One early death resulted from graft failure. There were two instances of paraparesis or paraplegia, with one associated early death. A single stent was deployed in 27 patients, two stents were required in 14 patients, and three stents were required in three patients. In 23 patients, vascular access was attained through the femoral artery; abdominal aortic access, either native or graft, was necessary in the remaining 21 patients. Twelve grafts were placed in conjunction with open abdominal aortic surgical procedures. Mean follow-up (98% complete) was 12.6 months (range 1 to 34 months). One late death occurred from aneurysmal expansion and rupture in a patient with a persistent midgraft leak. The second late death may have resulted from aneurysmal rupture. Immediate thrombosis was achieved in 36 patients, and late thrombosis was achieved in three others. Failure to achieve complete aneurysmal thrombosis occurred in five patients, however, and one individual (previously noted) died of aneurysmal expansion and rupture; the remaining four are being carefully monitored. Only one patient has required conversion of the stent to an open procedure; a contained rupture of the false lumen of a chronic dissection eventually necessitated total descending thoracic aortic exclusion.These early results support the hypothesis that endovascular stent-graft placement may be a safe and durable treatment for selected patients with aneurysmal disease of the descending thoracic aorta. Large introducer size (26F outer diameter) and relatively limited angulation capability, as well as imprecise deployment techniques, currently limit its applicability. Distal embolization and stent migration have not been observed. Failure to achieve complete aneurysmal thrombosis may allow continued aneurysmal expansion and rupture. Further follow-up is clearly necessary to evaluate the true long-term effectiveness of this procedure.

    View details for Web of Science ID A1996UK88400026

    View details for PubMedID 8622303

  • Perspective volume rendering of CT and MR images: Applications for endoscopic imaging RADIOLOGY Rubin, G. D., Beaulieu, C. F., Argiro, V., Ringl, H., Norbash, A. M., Feller, J. F., Dake, M. D., Jeffrey, R. B., Napel, S. 1996; 199 (2): 321-330


    To use perspective volume rendering (PVR) of computed tomographic (CT) and magnetic resonance (MR) imaging data sets to simulate endoscopic views of human organ systems.Perspective views of helical CT and MR images were reconstructed from the data, and tissues were classified by assigning color and opacity based on their CT attenuation or MR signal intensity. "Flight paths" were constructed through anatomic regions by defining key views along a spline path. Twelve movies of the thoracic aorta (n=3), tracheobronchial tree (n=4), colon (n=3), paranasal sinuses (n=1), and shoulder joint (n=1) were generated to display images along the flight path. All abnormal results were confirmed at surgery.PVR fly-through enabled evaluation of the full range of tissue densities, signal intensities, and their three-dimensional spatial relationships.PVR is a novel way to present volumetric data and may enable noninvasive diagnostic endoscopy and provide an alternate method to analyze volumetric imaging data for primary diagnosis.

    View details for Web of Science ID A1996UG01100006

    View details for PubMedID 8668772

  • Catheter-directed thrombolysis for iliofemoral venous thrombosis. Seminars in vascular surgery Semba, C. P., Dake, M. D. 1996; 9 (1): 26-33


    The combination of catheter-directed thrombolytic therapy and endovascular stenting is a new and promising approach for treating acute and chronic thrombotic iliofemoral venous occlusions on the basis of the authors' initial experience in a small group of patients. In acute DVT, catheter-directed techniques provide more complete lysis than systemic infusions and early, aggressive interventional therapy may spare the patient from the life-long disability associated with the postphlebitic syndrome, by preserving valve function and eliminating the venous outflow obstruction. Immediate postthrombolysis venography can evaluate the underlying vein and assess the need for adjunctive treatment with angioplasty and/or stents. Urokinase has a high degree of safety with few complications when a catheter-directed approach rather than systemic infusion is used. Even patients with chronic DVT can benefit by reducing the obstruction to venous outflow if the occlusion is limited to the iliac vein and/or the inferior vena cava. Long-term follow-up studies are necessary to evaluate patency rates of the treated veins, determine whether successfully treated limbs have a lower frequency of recurrent DVT, and ascertain the frequency of chronic venous insufficiency compared with that in patients treated with anticoagulation alone. Based on our initial experience, a National Venous Thrombosis Registry was established in October 1994. The purpose of this multidisciplinary Registry is to prospectively document the long-term results of catheter-directed thrombolytic therapy for patients with iliofemoral DVT, with data now being collected from 40 leading medical centers around the United States. We hope that endovascular techniques for iliofemoral DVT will significantly reduce the immediate and long-term complications commonly associated with this difficult and often misunderstood clinical problem.

    View details for PubMedID 8665023

  • [Stent graft technique in thoracic aortic aneurysm. A new alternative to conventional surgery]. Läkartidningen Nyman, U., Dake, M. D. 1996; 93 (7): 584-588

    View details for PubMedID 8642921

  • [Ischemic complications of dissecting aneurysm of the aorta. Treatment with percutaneous stents and fenestration]. Läkartidningen Nyman, U., Dake, M. D. 1996; 93 (7): 577-582

    View details for PubMedID 8642920

  • Aortic dissection: Percutaneous management of ischemic complications with endovascular stents and balloon fenestration 49th Annual Meeting of the Society-for-Vascular-Surgery Slonim, S. M., Nyman, U., Semba, C. P., Miller, D. C., Mitchell, R. S., Dake, M. D. MOSBY-ELSEVIER. 1996: 241–51


    The purpose of this study was to evaluate endovascular stenting (EVS) and balloon fenestration (BF) of intimal flaps for the management of lower extremity, renal, and visceral ischemia in acute or chronic aortic dissection.Twenty-two patients (16 male, 6 female) with a median age of 53 years (range 35 to 77 years) underwent percutaneous treatment for peripheral ischemic complications of 12 type A (five acute, seven chronic) and 10 type B (nine acute, one chronic) aortic dissections.Ten patients had leg ischemia, 13 had renal ischemia, and 6 had visceral ischemia. Sixteen patients were treated with EVS including 11 with renal, 6 with lower extremity, 2 with superior mesenteric artery, and 2 with aortic stents. Three patients had BF of the intimal flap, and three had BF in combination with EVS. Revascularization with clinical success was achieved in all 22 patients. Two patients died 3 days and 13.4 months after the procedure was performed, respectively. Of the remaining 20 patients, 1 is lost to follow-up, and 19 have persistent relief of clinical symptoms. Mean follow-up time is 13.7 months (range 1.1 to 46.5 months). One case was complicated by guidewire-induced perinephric hematoma.EVS and BF provide a safe and effective percutaneous method for managing peripheral ischemic complications of aortic dissection.

    View details for Web of Science ID A1996TW97700012

    View details for PubMedID 8637101

  • Hepatic laceration from wedged venography performed before transjugular intrahepatic portosystemic shunt placement JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Saperstein, L., Nyman, U., Dale, M. D. 1996; 7 (1): 143-146


    Transjugular intrahepatic portosystemic shunt (TIPS) placement is an increasingly used, nonoperative technique for treating variceal bleeding and refractory ascites secondary to portal hypertension. Since the first clinical TIPS case in 1989, the procedure has undergone significant technical refinement to improve the safety and efficacy of shunt placement. A major technical challenge of TIPS creation is passage of the transjugular needle from the hepatic vein into the portal vein. Perforation of the liver capsule from an errant needle pass can lead to massive intraperitoneal bleeding. To minimize the number of needle passes required to enter the portal vein, investigators have devised a variety of techniques to visualize the portal vein anatomy including direct transhepatic catheterization of the portal vein, superior mesenteric artery (SMA) angiography, real-time ultrasound (US) guidance and refluxing contrast medium into the portal vein with wedged hepatic venography. While these technical improvements have made TIPS a safe and attractive alternative to conventional surgical shunts, the procedure remains technically challenging and lethal hemorrhagic complications can occur when the liver capsule is perforated during the course of the procedure. To our knowledge, there are no reported major complications directly related to the wedged hepatic venogram prior to TIPS. We describe an unusual series of severe liver injuries from wedged hepatic venography during attempts to localize the portal vein.

    View details for Web of Science ID A1996UQ43700026

    View details for PubMedID 8773990

  • Endovascular thrombolytic therapy for deep venous thrombosis SEMINARS IN RESPIRATORY AND CRITICAL CARE MEDICINE Semba, C. P., Kee, S. T., Dake, M. D. 1996; 17 (1): 87-94


    To evaluate the feasibility of stent-grafts for treatment of isolated iliac artery aneurysms (IAAs).Nine IAAs in eight patients were treated with transluminally placed endovascular stent-grafts. All patients were men (median age, 72 years). In three, the aneurysm involved both the common and internal iliac arteries. In one, common and external iliac arteries were involved. The other aneurysms involved only the common iliac artery. Two aneurysms were treated with balloon-expandable stents covered with polytetrafluoroethylene (PTFE) graft material, three were treated with self-expanding Z-stents covered with a woven polyester graft, and four were treated with self-expanding Z-stents covered with PTFE.Transluminal placement of the stents was successful in all patients with thrombosis of the aneurysms. There were no distal thromboembolic events, deaths, or infections. The median follow-up period was 8.5 months.Initial results suggest that transluminal stent-graft placement for treating isolated IAAs is a safe and effective alternative to surgery in selected patients. Long-term follow-up data are needed before this approach can be recommended for the primary treatment of IAAs.

    View details for Web of Science ID A1995TG33300043

    View details for PubMedID 7480759

  • Thrombolytic therapy in venous occlusive disease. Journal of vascular and interventional radiology Dake, M. D., Semba, C. P. 1995; 6 (6): 73S-77S

    View details for PubMedID 8770846

  • Thrombolytic therapy in venous occlusive disease Summit Meeting on Thrombolytic Therapy in Peripheral Vascular Disease Dake, M. D., Semba, C. P. LIPPINCOTT-RAVEN PUBL. 1995: S73–S77
  • Ischemia of the throwing hand in major league baseball pitchers: Embolic occlusion from aneurysms of axillary artery branches JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kee, S. T., Dake, M. D., WolfeJohnson, B., Semba, C. P., Zarins, C. K., Olcott, C. 1995; 6 (6): 979-982

    View details for Web of Science ID A1995UQ43600025

    View details for PubMedID 8850680

  • ENDOVASCULAR STENT-GRAFTING AFTER ARCH ANEURYSM REPAIR USING THE ELEPHANT TRUNK ANNALS OF THORACIC SURGERY Fann, J. I., Dake, M. D., Semba, C. P., Liddell, R. P., Pfeffer, T. A., Miller, D. C. 1995; 60 (4): 1102-1105


    A 68-year-old woman with severe chronic obstructive pulmonary disease, aortic valvular insufficiency, and diffuse thoracic aortic aneurysm underwent aortic valve replacement and separate Dacron graft replacement of the ascending aortic and arch aneurysms using the elephant trunk technique. She was discharged on the tenth postoperative day. Five months later, she underwent endovascular stent-graft repair of the descending thoracic aortic aneurysm. She recovered uneventfully, and was discharged on the third postoperative day. Follow-up computed tomography at 6 months demonstrated exclusion of all flow into the descending thoracic aortic aneurysm. The elephant trunk technique followed by endovascular stent-grafting of the descending thoracic component is a potential therapeutic option in selected high-risk patients with diffuse aortic aneurysmal disease.

    View details for Web of Science ID A1995RZ17900045

    View details for PubMedID 7574959

  • VASCULAR INTERVENTION Conference on Developing a Long-Term Plan for Imaging Research Dake, M. D. ASSOC UNIV RADIOLOGISTS. 1995: S126–S127

    View details for Web of Science ID A1995RT15800019

    View details for PubMedID 9419722


    View details for Web of Science ID A1995RJ95900043

    View details for PubMedID 7618575

  • ASSESSMENT OF LIVING RENAL DONORS WITH SPIRAL CT RADIOLOGY Rubin, G. D., Alfrey, E. J., Dake, M. D., Semba, C. P., Sommer, F. G., Kuo, P. C., Dafoe, D. C., WASKERWITZ, J. A., Bloch, D. A., Jeffrey, R. B. 1995; 195 (2): 457-462


    To determine whether spiral computed tomography (CT) can be used to evaluate potential living renal donors.Twelve potential living renal donors underwent spiral CT and conventional arteriography. CT angiography was performed with 30-second spiral acquisition during injection of 150 mL of nonionic iodinated contrast material into an antecubital vein at 5 mL/sec. Five minutes after injection, a frontal abdominal scout projection was obtained to assess the renal collecting system. Results of blinded interpretations of axial CT angiograms, three-dimensional CT angiograms, and conventional arteriograms were correlated with intraoperative findings in 11 cases.Axial and three-dimensional CT angiography were 100% sensitive for identifying seven accessory renal arteries and 14% and 93% sensitive for identifying five prehilar renal artery branches. Renal venous anomalies were confirmed in three patients at surgery. Operative management changed in four of 11 patients who underwent donor nephrectomy.Spiral CT holds promise as a single examination for anatomic assessment of living renal donors.

    View details for Web of Science ID A1995QU71700028

    View details for PubMedID 7724766



    The ability of three different intravascular stents (Gianturco-Roubin, Palmaz-Schatz, and CV Rad), and two different metals (stainless steel and tantalum) to resist vasoconstriction was evaluated in an intact artery ex vivo model.Stents were deployed in 21 rabbit thoracic aortae and five dog carotid arteries, which were constricted with phenylephrine and serotonin, respectively. Vasoconstriction was measured with the use of high-frequency ultrasonic imaging.The maximal vasoconstriction of the control segment was 37.7% +/- 2.6 with rabbit aortae and 36.3% +/- 4.1 with dog carotid arteries, while the average maximal constriction for all segments in which stents were placed was 5.7% +/- 1.1 (P < .01). The maximal constriction of the Gianturco-Roubin stainless steel stent was 9.4% +/- 2.7 versus 7.9% +/- 1.6 with the tantalum version (P = .65). Both designs showed somewhat greater constriction compared with either the Palmaz-Schatz (3.3% +/- 0.9) or the CV Rad (1.4% +/- 1.1) stents.Although all of the stents tested substantially resist arterial vasoconstrictive forces, the Palmaz-Schatz and CV Rad stents resist vasoconstriction to a greater degree than the Gianturco-Roubin stents. Tantalum and stainless steel stents of the same design (Gianturco-Roubin) appear similar in their ability to resist vasoconstrictive forces.

    View details for Web of Science ID A1995RC62600011

    View details for PubMedID 7647439

  • Guidelines for development and use of transluminally placed endovascular prosthetic grafts in the arterial system. Endovascular Graft Committee. Journal of vascular and interventional radiology Veith, F. J., Abbott, W. M., Yao, J. S., Goldstone, J., White, R. A., Abel, D., Dake, M. D., Ernst, C. B., Fogarty, T. J., Johnston, K. W. 1995; 6 (3): 477-491

    View details for PubMedID 7647455

  • Guidelines for development and use of transluminally placed endovascular prosthetic grafts in the arterial system. Endovascular Graft Committee. Journal of vascular surgery Veith, F. J., Abbott, W. M., Yao, J. S., Goldstone, J., White, R. A., Abel, D., Dake, M. D., ERNEST, C. B., Fogarty, T. J., Johnston, K. W. 1995; 21 (4): 670-685

    View details for PubMedID 7707571



    Management of bleeding esophageal varices due to portal hypertension has traditionally relied on endoscopic sclerotherapy and operative intervention with placement of a portosystemic shunt. Although percutaneous decompression of portal hypertension was investigated 25 years ago, it was not clinically feasible until recently. With the advent of intravascular stents, the technique of creating a transjugular intrahepatic portosystemic shunt (TIPS) can now be effectively applied to treat the complications of portal hypertension, including variceal hemorrhage and refractory ascites. Since its introduction in 1989, TIPS has enjoyed widespread clinical application. The initial results with this procedure are encouraging and suggest that it is an effective means of reducing the frequency of variceal hemorrhage in patients with portal hypertension. The long-term patency rate and frequency of complications, however, have not been clearly defined. Similarly, the role of TIPS in the treatment of refractory ascites, Budd-Chiari syndrome, and hepatorenal syndrome remains unclear because sufficient data do not yet exist to support its general use in these settings.

    View details for Web of Science ID A1995QT17500009

    View details for PubMedID 7598487

  • IS THERE A ROLE FOR STENT-GRAFTS IN THE TREATMENT OF VASCULAR DISEASE OTHER THAN ANEURYSMS 7th Annual International Symposium on Vascular Diagnosis and Intervention Dake, M. D., Cragg, A. MIAMI VASCULAR INST. 1995: 213–215


    Three-dimensional CT angiography is a new modality for minimally invasive vascular imaging. Meticulous attention to technique is critical to optimizing image quality and achieving diagnostic images. In this article, the properties of spiral CT acquisitions, intravenous contrast delivery, and three-dimensional rendering techniques, as they pertain to the optimization of CT angiograms, are discussed. Next, a review of initial investigations into the clinical applicability of CT angiography in the cranium, neck, chest, abdomen, and pelvis is provided. Finally, CT angiography is compared with MR angiography and conventional angiography.

    View details for Web of Science ID A1995QE27500005

    View details for PubMedID 7824697



    The usual treatment for thoracic aortic aneurysms is surgical replacement with a prosthetic graft, but the associated morbidity and mortality are considerable. We studied the use of transluminally placed endovascular stent-graft devices as an alternative to surgical repair.We evaluated the feasibility, safety, and effectiveness of transluminally placed stent-graft to treat descending thoracic aortic aneurysms in 13 patients over a 24-month period. Atherosclerotic, anastomotic, and post-traumatic true or false aneurysms and aortic dissections were treated. The mean diameter of the aneurysms was 6.1 cm (range, 5 to 8). The endovascular stent-grafts were custom-designed for each patient and were constructed of self-expanding stainless-steel stents covered with woven Dacron grafts.Endovascular placement of the stent-graft prosthesis was successful in all patients. There was complete thrombosis of the thoracic aortic aneurysm surrounding the stent-graft in 12 patients, and partial thrombosis in 1. Two patients initially had small, residual patent proximal tracts into the aneurysm sac, but both tracts thrombosed within two months after the procedure. In four patients, two prostheses were required to bridge the aneurysm adequately. There have been no deaths or instances of paraplegia, stroke, distal embolization, or infection during an average follow-up of 11.6 months. One patient with an extensive chronic aortic dissection required open surgical graft replacement four months later because of progressive dilatation of the arch.These preliminary results demonstrate that endovascular stent-graft repair is safe in highly selected patients with descending thoracic aortic aneurysms. This new method of treatment will, however, require careful long-term evaluation.

    View details for Web of Science ID A1994PZ26600001

    View details for PubMedID 7984192


    View details for Web of Science ID A1994PE12000022

    View details for PubMedID 8073524



    To report initial clinical experience with stent placement in the cerebrovascular circulation.Four patients underwent arterial or venous stent placement. Two patients had cervical internal carotid artery dissections, with aneurysms and stenoses of the distal cervical carotid artery. Two patients had venous occlusive disease involving the major dural sinuses, with substantial pressure gradients across the stenoses.Immediately after stent placement, the true arterial lumina returned to normal diameter and both carotid aneurysms were more than 90% occluded. Follow-up angiography demonstrated continued improvement in the arterial aneurysms. Both patients with dural sinus venous occlusive disease showed substantial improvement of the sinus stenoses and substantial reversal of the pressure gradients after venous stent placement. At follow-up, these patients have done well.This preliminary experience suggests there may be a role for stents in the management of arterial and venous cerebrovascular disease, including carotid artery dissection and venous occlusive disease.

    View details for Web of Science ID A1994NG95500026

    View details for PubMedID 8153318



    To evaluate the efficacy of catheter-directed thrombolysis with urokinase in treating symptomatic iliofemoral deep venous thrombosis (DVT).Twenty-one consecutive patients with iliofemoral DVT underwent treatment for 27 affected limbs (acute DVT, n = 20; chronic DVT, n = 7). The average urokinase dose was 4.9 million IU (range, 1.4 million to 16.0 million IU) infused over an average of 30 hours (range, 15-74 hours).Lysis was complete in 18 (72%), partial in five (20%), and not achieved in two (8%) of 25 treated limbs. Two chronically occluded iliac veins could not be crossed with a guide wire and did not receive urokinase. Sixteen limbs had underlying venous stenoses (> 50%) that were treated with angioplasty (n = 2) or angioplasty and stent placement (n = 14). There were no major complications or clinically detectable pulmonary emboli. The technical and clinical success rates were 85%.This initial experience suggests that catheter-directed thrombolysis with urokinase for treatment of symptomatic iliofemoral DVT is safe and effective.

    View details for Web of Science ID A1994NG95500034

    View details for PubMedID 8153327



    Spiral CT angiography is a technical innovation in vascular imaging that can produce spectacular three-dimensional reconstructions of the abdominal vessels and organs using modified CT scanning techniques. Rapid volume data acquisition allows contrast material to be imaged in the arterial or venous phase. CT reconstruction in cross-sections avoids superimposition of overlying structures. The combination of these features allows spiral CT angiography to produce extraordinary images of the abdominal vasculature and organs. This review outlines fundamental techniques in spiral CT angiography and summarizes our initial clinical experience at Stanford University Medical Center.

    View details for Web of Science ID A1994NG27900006

    View details for PubMedID 8198819

  • SPIRAL CT OF RENAL-ARTERY STENOSIS - COMPARISON OF 3-DIMENSIONAL RENDERING TECHNIQUES RADIOLOGY Rubin, G. D., Dake, M. D., Napel, S., Jeffrey, R. B., McDonnell, C. H., Sommer, F. G., Wexler, L., Williams, D. M. 1994; 190 (1): 181-189


    To evaluate the accuracy of computed tomographic (CT) angiography in the detection of renal artery stenosis (RAS).CT angiography was performed in 31 patients undergoing conventional renal arteriography. CT angiographic data were reconstructed with shaded surface display (SSD) and maximum-intensity projection (MIP). Stenosis was graded with a four-point scale (grades 0-3). The presence of mural calcification, poststenotic dilatation, and nephrographic abnormalities was also noted.CT angiography depicted all main (n = 62) and accessory (n = 11) renal arteries that were seen at conventional arteriography. MIP CT angiography was 92% sensitive and 83% specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). SSD CT angiography was 59% sensitive and 82% specific for the detection of grade 2-3 stenoses. The accuracy of stenosis grading was 80% with MIP and 55% with SSD CT angiography. Poststenotic dilatation and the presence of an abnormal nephrogram were 85% and 98% specific, respectively.CT angiography shows promise in the diagnosis of RAS. The accuracy of CT angiography varies with the three-dimensional rendering technique employed.

    View details for Web of Science ID A1994MW25300036

    View details for PubMedID 8259402



    To describe and estimate the frequency of fibroelastic cords or bands projecting from the false lumen wall ("aortic cobwebs") in acute and chronic dissections.Pathologic specimens (n = 23), routine magnetic resonance (MR) images (n = 27), and intravascular (n = 5) and transesophageal (n = 3) ultrasound (US) images from 43 patients with aortic dissection were reviewed, and the presence and configuration of cobwebs were noted.Aortic cobwebs usually bridge the junction of the dissection flap with the outer wall of the false lumen (the line of dissection) but occasionally project like small tendrils from the false lumen wall remote from the line of dissection. Cobwebs were found in 17 of 23 pathologic specimens and on six of 27 MR images, two of five intravascular US scans, and one of three transesophageal US scans.Aortic cobwebs most likely represent residual ribbons of media that have been incompletely sheared from the aortic wall during the dissection process. As such, they can serve as an anatomic marker of the false lumen. They are occasionally seen on routine aortic images and may, therefore, prove useful for orientation during percutaneous or surgical interventional procedures to relieve ischemic complications of aortic dissection.

    View details for Web of Science ID A1994MW25300034

    View details for PubMedID 8259399



    Intravascular ultrasonography, balloon angioplasty, stent placement, and endovascular septal fenestration have been used in the evaluation and treatment of vascular complications of acute and chronic aortic dissection in five patients. There were three men and two women with an average age of 52 years (range 39 to 64 years). There were three chronic type A dissections, one acute type B, and one subacute type B dissection. Intravascular ultrasonography was used in all five cases. The three patients with chronic type A dissections underwent unilateral renal artery angioplasty (RA PTA) and stent placement; one patient with an acute type B dissection and associated fibromuscular dysplasia underwent bilateral RA PTA without stent placement. These procedures were performed to ameliorate severe hypertension. The final patient, with a subacute type B dissection, underwent iliac artery stenting to correct severe lower extremity ischemia. During a second intervention, this patient, who also had bowel ischemia and nonresolving acute renal failure, underwent balloon dilatation of a preexisting septal fenestration to augment visceral blood supply and bilateral RA PTA and stent placement in an effort to improve renal function. This patient eventually died of gut ischemia. After RA PTA and stent placement, one patient had a major intrarenal hemorrhage that required coil embolization and transfusion. In the four survivors, RA PTA and stent placement resulted in immediate improvement in blood pressure control. This response has been sustained during follow-up intervals ranging from 8 to 18 months (average 10 months). Intravascular ultrasonography can clearly demonstrate the pathologic anatomy associated with aortic dissection (even when angiography is ambiguous) and is essential for guiding therapeutic endovascular interventions. Further exploration of the efficacy of these endovascular techniques is warranted in this high-risk group of patients with aortic dissection who have appropriate clinical indications.

    View details for Web of Science ID A1993MM41200018

    View details for PubMedID 8264033

  • Tantalum balloon-expandable stent: in vivo swine studies. Journal of vascular and interventional radiology Fontaine, A. B., Dake, M. D., TSCHANG, T. P., Guertin, S., Stabbe, M. T., Dos Passos, S. 1993; 4 (6): 749-752


    The authors describe the experimental use of a balloon-expandable tantalum vascular stent in normal and atherosclerotic microswine.Thirty-one stents (15 iliac, 13 aorta, two femoral, one renal) were placed in 11 animals. Stents were placed in both normal and stenotic atherosclerotic arteries. The animals were killed and the stents explanted 2-32 weeks after placement. Arteriography was performed just prior to death in all cases.All stents were patent arteriographically and on gross inspection. Histopathologic study showed a thin, smooth, endothelial-lined neointima over the segments with stents. This covering had a mean thickness of 2.9 x 10(-5) mm and appeared maximally developed 2-5 weeks after stent placement. The stent design incorporates the following engineering and clinical considerations: minimal profile and surface area and maximal expansion ratio, hoop strength, flexibility, fluoroscopic visibility, biocompatibility, and ease of placement. When compressed and mounted on the balloon catheter, the stent is flexible. This allows it to be easily maneuvered through tortuous or diseased vessels. On expansion, the stent becomes a semirigid tubular structure composed of multiple rhomboid cells. Stents with an expanded diameter of less than 11 mm can be introduced through a 7-F vascular sheath.Initial results suggest that this stent successfully incorporates a number of theoretically desirable features for a vascular prosthesis, and it may offer some advantages over previously described devices.

    View details for PubMedID 8280995



    We sought to apply a new technique of computed tomographic angiography (CTA) to the preoperative and postoperative assessment of the abdominal aorta and its branches.After a peripheral intravenous contrast injection, the patient is continuously advanced through a spiral CT scanner, while maintaining a 30-second breath-hold. Thirty-five patients with abdominal aortic, renal, and visceral arterial disease have undergone CTA.Diagnostic three-dimensional images were obtained in patients with aortic aneurysms (n = 9), aortic dissections (n = 4), and mesenteric artery stenoses (n = 4). The technique has also been used to assess vessels after operative reconstruction or endovascular intervention in 18 patients. These preliminary studies have correlated well with conventional arteriographic findings. In aneurysmal disease both the lumen and mural thrombus and associated renal artery stenoses are visualized. The true and false channels of aortic dissections and the perfusion source of the visceral vessels are clearly shown; patency of visceral and renal reconstruction or stent placement are confirmed. CTA is relatively noninvasive and can be completed in less time than conventional angiography with less radiation exposure.This initial experience suggests that CTA may be a valuable alternative to conventional arteriography in the evaluation of the aorta and its branches.

    View details for Web of Science ID A1993MB16500013

    View details for PubMedID 8411473

  • Percutaneous femoropopliteal graft placement. Journal of vascular and interventional radiology Cragg, A. H., Dake, M. D. 1993; 4 (4): 455-463


    Femoropopliteal bypass surgery is now recommended for the treatment of long-segment or diffuse superficial femoral artery disease. The authors describe a technique for percutaneous placement of a prosthetic femoropopliteal graft.The technique has been accomplished with conventional polytetrafluoroethylene graft material and a variety of implantation techniques in eight patients.Technical success was achieved in all patients who underwent graft placement. Grafts up to 28 cm in length were placed, and graft patency was demonstrated up to 10 months after implantation. Six of the eight patients were asymptomatic during the follow-up period; one patient who had symptoms during this time underwent thrombolysis and redilation of the distal stent, and the symptoms resolved. In the other patient with symptoms, the procedure failed clinically because of poor runoff.This study demonstrates the feasibility of percutaneous graft placement in the femoral artery, but durability must be established in relation to traditional bypass surgery before it can be recommended on a wider scale.

    View details for PubMedID 8353341



    Femoropopliteal bypass surgery is now recommended for the treatment of long-segment or diffuse superficial femoral artery disease. The authors describe a technique for percutaneous placement of a prosthetic femoropopliteal graft. The technique has been accomplished with conventional polytetrafluoroethylene graft material and a variety of implantation techniques. Technical success was achieved in eight patients who underwent graft placement. Grafts up to 28 cm in length were placed, and graft patency was demonstrated up to 6 months after implantation. Six of the eight patients were asymptomatic during the follow-up period; one patient who had symptoms during this time underwent thrombolysis and redilation of the distal stent, and the symptoms resolved. This study demonstrates the feasibility of percutaneous graft placement in the femoral artery, but durability must be established in relation to traditional bypass surgery before it can be recommended on a wider scale.

    View details for Web of Science ID A1993LD19200010

    View details for PubMedID 8497609

  • New developments in vascular imaging. Spiral CT angiography. Administrative radiology : AR Semba, C., Dake, M. 1993; 12 (5): 28-?

    View details for PubMedID 10126848



    Acute traumatic aortic rupture is a lethal injury and requires immediate diagnosis and surgical repair. The standard of diagnosis for aortic rupture is aortography. In patients in whom the angiographic findings of rupture are subtle or uncertain, intravascular ultrasound (IVUS) imaging of the descending aorta has been useful in confirming or excluding mural injury. However, because IVUS is unable to provide a complete and expeditious survey of the aorta and brachiocephalic arteries, the diagnosis of rupture will continue to rely on aortography or current generation computed tomography.

    View details for Web of Science ID A1993KX46700003

    View details for PubMedID 8489785

  • INTRAVASCULAR STENTING OF ACUTE EXPERIMENTAL TYPE-B DISSECTIONS 1992 Annual Meeting of the Association-for-Academic-Surgery Moon, M. R., Dake, M. D., Pelc, L. R., Liddell, R., Castro, L. J., Mitchell, R. S., Miller, D. C. ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS. 1993: 381–88


    To evaluate the efficacy of intravascular stenting for acute aortic dissection, 12 dogs underwent surgical creation of an acute type B dissection. Intravascular ultrasound evaluated luminal diameter, distal propagation, and branch involvement. Three animals underwent no further treatment (control). In 9 dogs, balloon-expandable intravascular stents (15-20 mm) were placed proximally to compress the intimal flap. One dog with a small dissection had complete obliteration of the false lumen after initial stent placement. Six dogs with extension below the diaphragm were initially stented proximally to restore flow; 3 were left with a residual distal false lumen, while 3 had additional stents placed to obliterate their entire false lumen. In the final 2 dogs, proximal stenting resulted only in partial compression of the false lumen. Two animals died within 24 hr due to prolonged hemodynamic instability and aortic rupture at the intimal flap, respectively. Six weeks later, radiologic and histologic evaluation was performed on the 10 surviving animals. All stented true lumens were patent without thrombus formation, and stents were covered by neointima. In dogs with stenting of the entire dissection, the aortic wall had healed and no false lumen was present. However, in all dogs with only proximal obliteration, 1/2 with partial compression, and 2/3 controls, a patent false channel was present indicative of a chronic dissection. Thus, we found that intravascular stents can restore true lumen flow and obliterate the false lumen in experimental dissections; however, stenting limited to the proximal dissection does not prevent formation of a chronic residual patent false lumen.

    View details for Web of Science ID A1993LM66700020

    View details for PubMedID 8331933



    Spiral computed tomography (CT) is a new technology that couples continuous tube rotation with continuous table feed. This allows compilation of a data set that has continuous anatomic information without the establishment of arbitrary boundaries at section interfaces as in conventional CT. The unique method of data collection of the spiral scanner has been combined with a dynamic intravenous contrast material bolus to image abdominal vasculature, specifically, the aorta, renal arteries, and splanchnic circulation. Through various techniques of image processing, including surface renderings and maximum-intensity projections, it is possible to obtain excellent anatomic detail of the aorta and its major branches. The authors applied this technique in 15 patients and reliably saw third-order aortic branches as well as third-order splenic-portal venous anatomic detail with remarkable clarity. Pathologic conditions detected include stenotic renal arteries, abdominal aortic dissection, abdominal aortic aneurysm, and celiac bypass graft occlusion.

    View details for Web of Science ID A1993KD15300033

    View details for PubMedID 8416556

  • CT ANGIOGRAPHY WITH SPIRAL CT AND MAXIMUM INTENSITY PROJECTION RADIOLOGY Napel, S., Marks, M. P., Rubin, G. D., Dake, M. D., McDonnell, C. H., Song, S. M., Enzmann, D. R., Jeffrey, R. B. 1992; 185 (2): 607-610


    The authors describe a technique for obtaining angiographic images by means of spiral computed tomography (CT), preprocessing of reconstructed three-dimensional sections to suppress bone, and maximum intensity projection. The technique has some limitations, but preliminary results in 48 patients have shown excellent anatomic correlation with conventional angiography in studies of the abdomen, the circle of Willis in the brain, and the extracranial carotid arteries. With continued development and evaluation, CT angiography may prove useful as a screening tool or replacement for conventional angiography in some patients.

    View details for Web of Science ID A1992JV36000058

    View details for PubMedID 1410382



    Vascular access failure in hemodialysis patients remains a significant problem. The use of thrombolytic agents and balloon angioplasty instead of or in conjunction with surgical revision, has been helpful in increasing the life span of vascular access in these patients. The application of newer endovascular therapies, such as vascular stents, may further improve the salvage rate of hemodialysis access sites. These stents may be particularly valuable in treating stenoses in large central veins. We present 2 cases in which a balloon-expandable Palmaz stent was used to treat a central venous stenosis causing signs of vascular access failure.

    View details for Web of Science ID A1992KL50800010

    View details for PubMedID 1292345


    View details for Web of Science ID A1992JQ07900004

    View details for PubMedID 1529832

  • Spiral CT creates 3-D neuro, body angiograms. Diagnostic imaging Rubin, G. D., Napel, S., Dake, M. D., Walker, P. J., McDonnell, C. H., Marks, M. P., Jeffrey, R. B. 1992; 14 (8): 66-74

    View details for PubMedID 10147535

  • COAXIAL TRANSTHORACIC FINE-NEEDLE BIOPSY IN PATIENTS WITH A HISTORY OF MALIGNANT-LYMPHOMA RADIOLOGY Wittich, G. R., Nowels, K. W., Korn, R. L., Walter, R. M., Lucas, D. E., Dake, M. D., Jeffrey, R. B. 1992; 183 (1): 175-178


    Efficacy and safety of coaxial transthoracic fine-needle biopsy were evaluated in 54 patients with a history of malignant lymphoma and new chest lesions. Twenty-one patients had recurrent lymphoma. Correct diagnosis was made in 17 of the 21 patients (81%) after one biopsy. The sensitivity increased to 95% with repeat needle biopsy in three patients. Immunophenotyping (determining phenotype by means of immunologic examination) was essential for a definitive diagnosis of lymphoma in three patients. Non-lymphomatous malignancies were correctly diagnosed in 14 patients. An infectious organism was identified in 11 of 19 patients (58%) with benign lesions. Pneumothorax occurred in eight patients (15%), necessitating placement of a chest tube in two (4%). Mild hemoptysis was observed in four patients (7%). The authors conclude that coaxial transthoracic fine-needle biopsy in patients with a history of lymphoma is safe and accurate. The use of large cutting needles or surgical biopsy can be restricted to patients with false-negative findings at percutaneous biopsy and to patients in whom histologic transformation of lymphoma is suspected.

    View details for Web of Science ID A1992HJ87400033

    View details for PubMedID 1549668

  • PALMAZ STENT IN ATHEROSCLEROTIC STENOSES INVOLVING THE OSTIA OF THE RENAL-ARTERIES - PRELIMINARY-REPORT OF A MULTICENTER STUDY RADIOLOGY Rees, C. R., Palmaz, J. C., Becker, G. J., Ehrman, K. O., Richter, G. M., Noeldge, G., Katzen, B. T., Dake, M. D., Schwarten, D. E. 1991; 181 (2): 507-514


    Palmaz balloon-expandable stents were placed in 28 hypertensive patients with atherosclerosis involving the ostia of the renal arteries. Stents were placed to treat elastic recoil immediately after conventional angioplasty in 20 patients and restenosis after percutaneous transluminal angioplasty in eight patients. Technical success (greater than 30% residual stenosis) was achieved in 27 patients. Complications occurred in five patients. At follow-up (1-25 months), hypertension was cured in three patients and improved in 15 patients, with a cumulative cure or improvement of 64% at 6 months. Of 14 patients with a serum creatinine level of 1.5 mg/dL (132.6 mumol/L) or greater before the placement of stents, five demonstrated improved renal function, five showed stabilization of their condition, and four demonstrated deterioration. Follow-up angiography (2-18 months) was performed in 18 patients. Restenosis was present in seven patients and was accompanied by a relapse of hypertension in only three patients. Of the other four patients with restenosis, two had no initial improvement and two had an initial response without a relapse of hypertension. In this preliminary study, renal stents were beneficial in many patients with poor results from conventional angioplasty for ostial atheroma.

    View details for Web of Science ID A1991GL84100034

    View details for PubMedID 1924796



    The recent development and rapid expansion of new percutaneous vascular interventional devices designed to remove or remodel atherosclerotic plaque has been accompanied by equally strong interest in imaging modalities guidance systems to more accurately evaluate disease and better facilitate vascular interventions than traditional angiography. Although contrast angiography remains the standard for diagnostic evaluation of coronary and peripheral arteries, intravascular ultrasound has the potential to offer more precise information about vascular anatomy and disease. Intravascular ultrasonography has been able to provide specific information regarding vessel lumen and wall. Such information is not available by traditional diagnostic methods and may become essential in the future diagnosis, staging, and treatment of atherosclerosis.

    View details for Web of Science ID A1991FJ46400007

    View details for PubMedID 2049266

  • Directional atherectomy in the treatment of stenotic dialysis access fistulas. Journal of vascular and interventional radiology Zemel, G., Katzen, B. T., Dake, M. D., Benenati, J. F., Lempert, T. E., Moskowitz, L. 1990; 1 (1): 35-38


    Directional atherectomy has proved useful in the treatment of peripheral vascular occlusive disease, and the authors have begun using this modality in the treatment of patients with failing hemodialysis access fistulas. The authors describe their initial experience with 13 patients in whom directional atherectomy was used to treat stenotic hemodialysis fistulas. Directional atherectomy was the sole treatment modality for eight patients. Three patients underwent atherectomy after unsuccessful percutaneous transluminal angioplasty (PTA). In two patients, unsuccessful atherectomy necessitated subsequent PTA. Directional atherectomy was successful in 10 of 13 patients. In seven of these 10 patients who are still alive, the dialysis fistulas remain patent. Directional atherectomy is a safe and useful technique in the percutaneous treatment of hemodialysis fistula stenosis. Early data indicate patency rates that may be higher than those reported with PTA.

    View details for PubMedID 2134034

  • Peripheral angiography, angioplasty, atherectomy, laser techniques, thrombolysis, and stents. Current opinion in radiology Dake, M. D. 1990; 2 (2): 239-249

    View details for PubMedID 2143920

  • PLACEMENT OF BALLOON-EXPANDABLE INTRALUMINAL STENTS IN ILIAC ARTERIES - 1ST 171 PROCEDURES 15TH ANNUAL MEETING OF THE SOC OF CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY ( PREPRINT ) Palmaz, J. C., Garcia, O. J., Schatz, R. A., Rees, C. R., Roeren, T., Richter, G. M., Noeldge, G., Gardiner, G. A., Becker, G. J., Walker, C., Stagg, J., Katzen, B. T., Dake, M. D., PAOLINI, R. M., McLean, G. K., Lammer, J., Schwarten, D. E., Tio, F. O., Root, H. D., Rogers, W. RADIOLOGICAL SOC NORTH AMER. 1990: 969–75


    The cause of superior vena cava syndrome (SVCS) in two patients was identified by means of endovascular biopsy of the superior vena cava (SVC) performed with a percutaneous atherectomy catheter. In both cases, the extracted tissues were neoplastic, therefore obviating additional invasive procedures. After a specific diagnosis was established, external-beam radiation therapy was used to treat the SVCS. The atherectomy catheter was used in conjunction with other percutaneous techniques, including balloon angioplasty and endovascular stenting of the SVC.

    View details for Web of Science ID A1990CQ00800011

    View details for PubMedID 2305100

  • BLUE TOE SYNDROME - TREATMENT WITH PERCUTANEOUS ATHERECTOMY RADIOLOGY Dolmatch, B. L., Rholl, K. S., MOSKOWITZ, L. B., Dake, M. D., VANBREDA, A., Kaplan, J. O., Katzen, B. T. 1989; 173 (3): 799-804


    "Blue toe syndrome" refers to digital ischemia of the foot in the presence of palpable or Doppler audible pedal pulses. This clinical syndrome is caused by microembolization to small vessels from a proximal source. The use of percutaneous transluminal atherectomy is described in the treatment of embologenic superficial femoral artery lesions in seven patients. All seven had prompt healing of the ischemic toes, and none required surgical revascularization or amputation. One patient developed a recurrent stenosis at the atherectomy site and had a second episode of digital ischemia, which was treated by means of atherectomy with a larger device. Histologic study of atherectomy specimens suggests that emboli arise from adherent fibrinoplatelet aggregates or thrombus and less often from cholesterol-rich atheromatous plaque. Although either percutaneous transluminal angioplasty or atherectomy can be used to treat the underlying stenosis, percutaneous atherectomy offers the advantage of nonsurgical removal of embologenic material and provides material for histologic study. Percutaneous atherectomy is an effective method of treating embologenic superficial femoral stenoses in patients with ipsilateral blue toe syndrome.

    View details for Web of Science ID A1989CA08100044

    View details for PubMedID 2813788

  • NONCORONARY ANGIOPLASTY RADIOLOGY Becker, G. J., Katzen, B. T., Dake, M. D. 1989; 170 (3): 921-940


    PTA is an established method of revascularization in a variety of medical conditions. It is performed for specific morphologic and clinical indications. PTA is the procedure of choice in Fontaine stage IIB through IV lower extremity ischemia due to iliac and/or femoropopliteal stenosis or short occlusion. Its role is less certain in infrapopliteal disease, although current studies have begun to establish long-term effectiveness. PTA is the procedure of choice for renal revascularization in renovascular hypertension due to fibromuscular disease or non-ostial atherosclerosis, selected cases of renal artery stenosis associated with renal insufficiency, and transplant renal artery stenosis. It is also useful in treating the renovascular component of complex hypertension and may be indicated in severe renal artery stenosis (75%-99%), even in the absence of clinically demonstrable RVHTN. PTA has limited applications in the venous system and only short-term success in the treatment of stenoses in dialysis access fistulas. PTA often serves as an important adjunct to surgical revascularization by providing improved inflow or outflow. PTA is the procedure of choice when anatomically feasible in subclavian steal syndrome. The role of PTA in carotid artery disease, particularly atheromatous disease of the internal carotid artery, is uncertain. The same may be said of PTA for vertebral artery stenosis, although the overwhelming majority of vertebral artery stenoses are morphologically suitable for PTA. PTA and surgery are both effective in the treatment of abdominal angina. There are more data available to verify the long-term patency of thromboendarterectomy and bypass grafts than PTA for mesenteric ischemia. However, since the technical success for PTA is high and since coronary co-morbidity is the most common cause of perioperative mortality in surgical series, PTA should be seriously considered as the procedure of first choice. Serious complications of PTA occur in approximately 5% of cases. Two to three percent of PTA patients have complications requiring surgery or causing a prolongation or alteration of hospital course. The morbidity, mortality, and cost associated with PTA are low. The discomfort is minor, and postprocedural recovery rapid. The major limitations of PTA include its unsuitability for some lesions (long-segment occlusions and stenoses, orifice lesions, eccentric lesions) and postangioplasty restenosis. These problems are being addressed by ongoing laboratory and clinical research. In the near future, it is likely that endoluminal transmural sonography of the vessel wall will help guide our interventions.

    View details for Web of Science ID A1989T273500001

    View details for PubMedID 2521745



    Development of an interventional radiology practice or section depends first on the commitment and ability of the interventionalist but is also contingent on an appropriate environment. Moreover, the interventionalist must attempt to change long-standing concepts and referral patterns with aggressive dissemination of information. He or she must be an advocate of the procedures offered, as well as their benefits to the patient and the health care system. One must actively include outpatient visits and admissions as part of services offered. Allies in this effort include primary care physicians, internists, hospital administration, and third-party payers. In addition, organized radiology can now offer some assistance through the Society of Cardiovascular and Interventional Radiology and the American College of Radiology. All of these factors will contribute significantly to the success of interventional radiology in both teaching and community hospital settings.

    View details for Web of Science ID A1989T273500006

    View details for PubMedID 2916063



    Amiodarone is an iodinated antiarrhythmic agent that is effective in the treatment of atrial and ventricular arrhythmias. A number of side effects are seen, including pulmonary toxicity and thyroid dysfunction. A patient with both amiodarone-induced pneumonitis and hyperthyroidism who exhibited abnormal gallium activity in the lungs, as well as diffuse gallium uptake in the thyroid gland is presented. The latter has not been previously reported and supports the concept of iodide-induced "thyroiditis" with gallium uptake reflecting the inflammatory response.

    View details for Web of Science ID A1988N099000006

    View details for PubMedID 3163535



    Because CT of spinal extraarachnoid metrizamide collections may be misleading, we reviewed the postmetrizamide CT scans of 425 patients in order to characterize the appearance of subdural or epidural metrizamide. Eight patients were found to have extraarachnoid metrizamide contrast collections. In all patients, both the subarachnoid space and the extraarachnoid collection were opacified with metrizamide. In seven patients, a subdural collection of metrizamide created a mass upon the opacified subarachnoid space. Three of these subdural collections were less dense than the opacified subarachnoid compartment and simulated soft-tissue disease, including tumor and an arteriovenous malformation. The hypodense collections are probably a result of leakage of metrizamide and cerebrospinal fluid through the spinal needle defect. CT clues for diagnosing these potentially misleading subdural collections include preservation of the normal dural and epidural interface, identification of small islands of metrizamide within a suspected soft-tissue "mass," the presence of concomitant epidural contrast material collections, and the absence of adjacent vertebral-body destruction.

    View details for Web of Science ID A1986D685000029

    View details for PubMedID 3488660



    Pyogenic brain stem abscess is rare. A case of spontaneous abscess of the medulla oblongata is reported in which the diagnosis was made preoperatively by computed tomography. Surgical drainage resulted in good functional recovery and radiological resolution of the lesion. This is the first reported case of survival in a patient with an abscess of the medulla oblongata. The pathophysiology, clinical symptoms, and radiological appearance of the entity are discussed. Prompt diagnosis and drainage are emphasized as important factors influencing survival.

    View details for Web of Science ID A1986A795100024

    View details for PubMedID 3703200



    Lumbar apophyseal fracture is an uncommon injury that occurs during adolescence. We described two cases in young adults with back pain. The radiographic findings were distinctive. In both cases CT demonstrated characteristic bony fragments displaced posteriorly into the spinal canal and a corresponding defect in the posteroinferior aspect of the vertebral body rim. Recognition of this entity is important in evaluating back pain in both adolescents and adults.

    View details for Web of Science ID A1985ALY9800012

    View details for PubMedID 3160730

  • GA-67 LUNG UPTAKE ASSOCIATED WITH AMIODARONE PULMONARY TOXICITY AMERICAN HEART JOURNAL Dake, M. D., Hattner, R., Warnock, M. L., Golden, J. A. 1985; 109 (5): 1114-1116

    View details for Web of Science ID A1985AGY1900033

    View details for PubMedID 3993525



    The mechanism of amiodarone-induced pulmonary toxicity is unknown. Two cases of amiodarone pulmonary toxicity are presented in which abnormal inclusion bodies containing whorls of membrane were seen on electron microscopy of extrapulmonary tissues. These cytoplasmic lysosomal inclusion bodies were observed in lymphocytes, plasma cells, granulocytes, tissue macrophages, and hepatocytes. These widespread histopathologic changes in extrapulmonary tissues and in a variety of cell types are similar to more extensively investigated findings in animal models that are thought to represent a drug-induced lysosomal storage disease, phospholipidosis.

    View details for Web of Science ID A1985ADP6400027

    View details for PubMedID 2983550



    The efficacy of bronchoalveolar lavage and transbronchial biopsy in diagnosing lung infection was determined in 276 fiberoptic bronchoscopic examinations done on 171 patients with known or suspected acquired immunodeficiency syndrome. Of 173 pathogens (Pneumocystis carinii, cytomegalovirus, Mycobacterium avium-intracellulare, Cryptococcus neoformans, M. tuberculosis, Coccidioides immitis, and Histoplasma capsulatum) identified during the initial evaluation or in the subsequent month, the initial bronchoscopic examination detected 166 (96%). Bronchoalveolar lavage and transbronchial biopsy had sensitivities of 86% and 87%, respectively. When bronchoscopy included both bronchoalveolar lavage and transbronchial biopsy, the yield for all pathogens was 98% and the sensitivity for P. carinii infections was 100%. Follow-up for at least 3 weeks after examination failed to detect any additional false-negative results. Fiberoptic bronchoscopy is extremely accurate for the detection of pathogens in patients with the acquired immunodeficiency syndrome, especially when bronchoalveolar lavage and transbronchial biopsy are combined. In patients at high risk of complications from transbronchial biopsy, bronchoalveolar lavage is sufficiently accurate to be used alone.

    View details for Web of Science ID A1985AKB6400003

    View details for PubMedID 2986505


    View details for Web of Science ID A1984SS11200032

    View details for PubMedID 6730498


    View details for Web of Science ID A1983QT32800043

    View details for PubMedID 6859696