Current status of the prospective, randomized trials of symptomatic carotid bifurcation disease.

Three contemporary trials that are studying patients who have symptomatic carotid disease have proven beyond doubt that CE is extremely beneficial in reducing the risk of future stroke in patients with high-grade stenosis (greater than 70%). The relative risk of major stroke is reduced by at least 80% at 2 years of follow-up. That such a remarkably positive result for surgery was not predicted is a consequence of the unanticipated malignant natural history of TIAs and minor stroke in severe carotid disease. Previous epidemiological studies had underestimated the risk of future stroke by almost threefold. The current studies also highlight the remarkable power of prospective clinical trials to evaluate the effectiveness of a surgical procedure. In the case of NASCET, only 659 patients were required to prove the benefit of CE, whereas, innumerable previous anecdotal cases had failed to provide a convincing answer. However it must be remembered that the benefit from CE is dependent on a low rate of perioperative morbidity and mortality, a strict measure of the degree of stenosis on angiography, recency of ischemic events, and unequivocal carotid symptoms. The ongoing study of patients with moderate degrees of carotid stenosis holds the promise that in the very near future precise guidelines, which have been properly evaluated by careful scientific scrutiny,, will be available to guide surgeons in the proper management of all patients who present with symptomatic carotid disease.