Carotid stenosis and perioperative stroke risk in symptomatic and asymptomatic patients undergoing vascular or coronary surgery.

BACKGROUND AND PURPOSE The management of asymptomatic carotid stenosis found before vascular or coronary surgery is unclear from the literature. We aimed to define the relation of carotid stenosis to perioperative stroke in all patients, symptomatic and asymptomatic, and so determine a policy for the management of asymptomatic carotid stenosis in patients requiring major surgery. METHODS We conducted a prospective clinical and Duplex ultrasound study of 358 consecutive noncarotid major vascular or coronary artery bypass operations, with a moratorium on endarterectomy for asymptomatic carotid stenosis. RESULTS There were 145 vascular and 213 coronary bypass operations. Ten of the 49 cases with prior symptoms of cerebral ischemia (38 carotid, 11 vertebrobasilar) had symptomatic stenosis of 50% or greater or occlusion, and 3 of these (30%) had ipsilateral perioperative cerebral infarction (95% confidence interval, 6.67% to 65.25%). Two of these occurred ipsilateral to symptomatic carotid occlusions, and 1 occurred ipsilateral to an 80% symptomatic stenosis. One symptomatic patient with bilateral 30% stenosis had a perioperative infarct in the asymptomatic hemisphere. Among the 309 asymptomatic patients, 1 perioperative infarct occurred ipsilateral to carotid stenosis of 30%. In all there were 5 (1.4%) perioperative (within 72 hours) and 2 late (after 18 days) strokes. All strokes were hemisphere infarcts confirmed by computed tomography. There were 53 cases with 50% or greater asymptomatic carotid stenosis or occlusion, including 28 with 80% or greater stenosis or occlusion. None had an ipsilateral perioperative stroke (95% confidence interval, 0% to 6.72%). CONCLUSIONS We conclude that the risk of perioperative stroke related to symptomatic carotid stenosis may be high, but for asymptomatic carotid stenosis the risk is low and does not justify preoperative prophylactic carotid endarterectomy.