Coronary artery stents are small hollow cylinders that can be deployed over the angioplasty balloons and left within the coronary arteries to keep the arteries open. Stents help prevent abrupt closure of arteries shortly after PTCA. They also prevent restenosis (recurrent narrowing of the arteries) several months after PTCA.
Coronary stents decrease the risks of arterial dissections, elastic recoil, and artery spasm that can occur after PTCA and cause re-occlusion of the artery. Studies have shown that the incidence of abrupt coronary artery closure after PTCA has declined dramatically with the introduction of coronary stents.
Coronary stents also help to keep the coronary arteries open in the longer-term. After a successful PTCA, as many as 30-40% of patients will develop recurrent narrowing (restenosis) at the site of inflation of the balloon, usually within six months following PTCA. Restenosis may or may not be accompanied by symptoms such as angina. Thus, restenosis often is detected by exercise stress tests performed four to six months after PTCA. The widespread use of coronary stents has reduced this incidence of restenosis by as much as 50%. The recent introduction of coated stents (stents that are coated with chemicals to further reduce restenosis) has reduced the incidence of restenosis to well under 10% and has been a major improvement in treatment.
Patients with coronary artery stents usually are maintained on full doses of daily aspirin. For the first 4-12 weeks after the placement of stents, patients are given an additional anti-platelet drug such as ticlopidine or clopidogrel because the metal surface of the stents may promote the formation of blood clots in the first several weeks after the stent is inserted. With the newer medicated stents, aspirin and clopidogrel are continued for a year or longer.
«Index of Heart Attack Treatment
«Coronary angiography and percutaneous transluminal coronary angioplasty
»Nitrates
Posts
No comments:
Post a Comment