Improved prognosis for asymptomatic carotid stenosis with prophylactic carotid endarterectomy

Background and Purpose: The value of carotid endarterectomy in asymptomatic patients with high-grade stenosis is controversial. The objective of this study is to compare the immediate and long-term outcome of patients after carotid endarterectomy for asymptomatic carotid stenosis (>75%) with the reported natural history of patients followed nonoperatively to determine whether carotid endarterectomy reduces the subsequent neurological event rate. Methods: The data from 141 carotid endarterectomies performed in 123 patients between January 1980 and December 1986 were reviewed from the perspective of perioperative results and long-term follow-up to January 1990, providing a follow-up ranging from 3 to 10 years. The mean follow-up was 56.6 months (range 27-117 months). Results: There were no perioperative deaths. There were two postoperative strokes: one in the cerebellar distribution and one in the middle cerebral distribution. During the course of follow-up, no patient suffered a stroke in the hemisphere ipsilateral to carotid endarterectomy. One patient developed ipsilateral transient ischemic attacks 24 months after surgery associated with carotid restenosis. A total of three patients developed four recurrent carotid stenoses, for an incidence of 2.8%. All four recurrences were corrected surgically. Conclusions: These findings are in marked contrast to the reported natural history of patients with >75% stenosis in which the 1-year neurological event rate is 18% and the 1-year stroke rate is 5%. Although final proof of efficacy for prophylactic carotid endarterectomy in asymptomatic patients will await the outcome of randomized trials, until these data are available, prophylactic carotid endarterectomy is justified in centers of excellence that can perform the surgery with low perioperative risk.