Drug-Eluting Stents

Blockages or increased resistance in the arteries of the heart may produce chest pain, hypoxia, hypertrophy and other complications. Treatment for these blockages vary according to the extent of the blockage. Some of these treatments include: surgery, medication, or "catheter-based procedures".

Catheter-based procedures are now seen more often with advances in biomedical engineering. These procedures consist of a physician passing a balloon catheter into the blocked artery and expanding the balloon the open the artery by compressing the blockage against the arterial wall. Although this is a very efficient procedure, some patients started experiencing renarrowing of the artery within 6 months of the angioplasty. This then brought biomedical engineers to think of a device that would prolong the effects of the angioplasty, coming up with the idea of a stent.

A stent is a small metal tube that is inserted into the arterie via a balloon catheter. This stent placed against the wall by inflating of the balloon catheter and deflating it to be removed. Although stents are more efficient than a simple angioplasty procedure, 1 in 5 patients still experience renarrowing of the arteries. Because of this problem, bioengineers have further developed medicated stents that inhibit or fully prevent tissue growth. This has reduced the number of patients with renarrowing or the arteries by half!

Although these stents can be a very efficient way to open blocked arteries, there are other risks involved. One of these risks include stent thrombosis, where a blood clot may develop in the stent. Because of this risk, sometimes patients are advised to use anticlotting medication. On the other hand, the US Food and Drug Administration reviewed these drug-eluting stents and concluded that they are safe for those who have uncomplicated medical histories. For those who have complicated medical histories, they must consult their cardiologist before undergoing a stent implantation procedure.

reference: http://circ.ahajournals.org/content/115/17/e426.full