Effects of balloon inflation on the atherosclerotic plaque.

Despite the fact that PTCA has been around for over three decades, the underlying mechanism is not completely understood. When transluminal angioplasty was first introduced, its effectiveness was attributed to compression and redistribution of atheromatous plaque; however, later studies demonstrated that the plaque is relatively incompressible. Nowadays, much more complex mechanisms are known to be responsible for the enlargement of the arterial lumen. The major mechanism of balloon angioplasty is postulated to be plaque fracture, with immediate formation of fissures within the atherosclerotic lesion, which provides channels for blood flow. On the other hand, fracture of the surface of an atherosclerotic plaque is known as a common cause of acute myocardial infarction and unstable angina and several reports suggest a relationship between restenosis and lesions resulting from balloon inflation. These two theories seem to be in conflict with each other. In this study we supposed that plaque rupture is a disadvantageous outcome of the balloon inflation and the influence of PTCA is due to varying the elastic property of the atherosclerotic plaque. Then this hypothesis was analyzed with finite element modelings.