In the past few years, many refinements have been developed in the
PTCA procedure. One common procedure used in PTCA is stent placement.
A stent is a tiny, expandable metal coil that is inserted into the
newly-opened area of the artery to help keep the artery from narrowing
or closing again.
Once the stent has been placed, tissue will begin to form over it
within a few days after the procedure. The stent will be completely
covered by tissue within a month or so.
It is necessary to take a medication, such as aspirin or clopidogrel
(Plavix), which decreases the "stickiness" of platelets (a
type of blood cells that clump together to form clots to stop
bleeding), in order to prevent blood clots from forming inside the stent.
Newer stents (drug-eluting stents, or DES) are coated with
medication to prevent the formation of scar tissue inside the stent.
These drug-eluting stents release medication within the blood vessel
itself.
This medication inhibits the overgrowth of tissue that
can occur within the stent. The effect of this medication is to deter
the narrowing of the newly stented blood vessel.
If scar tissue does form inside the stent, radiation therapy (called
brachytherapy) may be used to clear the scarred area and open up the vessel.