Carotid endarterectomy: current status, and effects of clinical trials.

With the interim results of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) now reported, it has been shown that carotid endarterectomy is superior to conventional medical therapy for the treatment of symptomatic patients with > 70% diameter-reducing stenosis. The Veterans' Administration trial in asymptomatic patients with a > 50% diameter-reducing stenosis has shown that endarterectomy is superior to conventional non-operative treatment for the prevention of transient ischemic attacks and strokes when these events are combined. The design, impact and potential shortcomings of these trials are reviewed.