When drug eluting stents were first invented, they were so well recieved that they "doubled the world market for stents to $5 Billion annually" (angioplasty.org). Designed with a drug coating to prevent renstenosis, or the closing of the arteries, they were thought to be the perfect solution for patient following angioplastey; Not only did the metal structure prevent most cases of renostenosis directly following angioplasty, but the drug prevented most cases of renostenosis following the implantation of a normal metal stent.
However, recent patterns in patients who use drug eluting stents has suggested they might be linked to problematic conditions. But because they were developed in the 90s, they are a fairly recent invention and have not been on the market long enough to be conclusively linked to any fatal event. Despite this, there is some evidence that they might be linked to an increased chance of thrombosis (clotting which causes blockage of a blood vessel), particularly "Late Stent Thrombosis," which, as its name implies, is thrombosis that occurs a year or two after the stent is implanted.
There are also other problems. Allergic inflamatory reactions, which increase the chance of thrombosis, are worried to be linked to use of Drug eluding stents. Though there is very little evidence to support this according to angioplasty.org, there are a large number of people who feel it could be related to the polymer used in creating the stent. One proposal to confront this problem is an allergy test in which polymers are tested on a patient before putting the stent in the body. Anti-platelet medication must also be taken to prevent platelets from forming on the stent, but due to the drugs which slow down cell growth on the stent, anit-platelet medication must be taken for a longer period of time than with regular metal stents and deal with all the risks that come from use of such medication (most notable of which is hemoraging).
http://www.ptca.org/des.html
http://www.aetna.com/cpb/medical/data/600_699/0621.html
http://heartdisease.about.com/od/angioplastystents/a/DESproblems.htm
http://www.ashcraftandgerel.com/stent_lawsuit.html
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2 comments:
You mentioned that this device is relatively new and was made in the 90's but it has been around 10 years, have they yet to test the outcomes in the patients?
I wonder if there is maybe another material that stents could be made out of so that clots wouldn't form and inflammation wouldn't occur in the first place.
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