Catheter Based Local Drug and Gene Delivery

Abstract

Percutaneous transluminal coronary angioplasty (PTCA) was introduced into clinical medicine in 1980 and in the ensuing years there has been an explosive growth in the number of procedures performed. Until just recently, however, there has been little advancement in reducing the frequency of restenosis and the incidence of angiographic restenosis, broadly defined as the partial or total reocclusion of the artery to 50% of the original lumen, has remained 50%. Although the use of the Palmaz-Schatz intracoronary stent [1,2] has reduced the angiographic restenosis rate to 30% this device is impractical in arteries with a diameter <3.0 mm and in arteries with unsuitable anatomy. In addition, stents actually elicit increased intimal accumulation. The clinical ramifications of restenosis include increased mortality, morbidity and health costs associated with repeat angioplasty or coronary bypass surgery. Therefore, recognition by both clinical cardiologists and vascular biologists that restenosis is a major clinical problem has lead to the evaluation of local drug or gene delivery as a therapeutic approach. Restenosis appears to be particularly well-suited for site-specific treatment as it has a defined initiation point, i.e. the angioplasty procedure, the process is completed within 6 months and the focal restenotic arterial segment. Other potential applications for local delivery include treatment of intracoronary thrombus formation and modification of the atherosclerotic plaque making it less suseptable to rupture.KeywordsArterial WallBalloon CatheterLocal DeliveryLocal Drug DeliveryMedial Smooth Muscle CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.