[Anti-platelet agents in peripheral vascular surgery]

Prescription of platelet inhibitors after arterial surgery is common use. The major concern of the vascular surgeon is to maintain patency of arterial reconstructions. Major causes of graft failure or arterial thrombosis are the non-thromboresistant nature of the grafts and of the endarterectomised or balloon-dilated surfaces, restenosis due to intimal hyperplasia and progression of atherosclerotic disease in in- or outflow vessels. Platelet adhesion and intimal injury are the primary causes in both processes of graft thrombosis and intimal hyperplasia. To understand how antiplatelet drugs can interfere with these processes, a brief review of platelet function, and of the main platelet inhibitors (aspirin, dypiridamole, ticlopidine) is given. The pathophysiology of intimal hyperplasia is discussed. From clinical trials of peripheral vascular surgery or percutaneous transluminal angioplasty with or without periprocedural antiplatelet therapy, it appears that platelet inhibitors reduce early failure rate by 50% (thrombosis rate at one year reduced from 40 to 20%). There is also evidence that antiplatelet drugs allow to slow down the progression of the atherosclerotic degenerative process in the outflow vessels and in other vascular territories. For the polyvascular patients with charged passed history, platelet inhibitors reduce the risk of myocardial or cerebral infarction by 30% (secondary prevention). Today, there is a general consensus that antiplatelet drugs, started the day before the procedure, are beneficial for early and late patency of peripheral vascular reconstructions (carotid endarterectomy, infrainguinal bypass grafts or endovascular procedures).