Carotid endarterectomy in patients with contralateral carotid occlusion.

In this study, we assessed the results of carotid endarterectomy in 357 patients with a carotid stenosis and contralateral carotid occlusion. The overall major neurologic morbidity was 0.6%, and the minor morbidity was 1.1%. The causes of four perioperative deaths (1.1%) were myocardial infarction in two patients, ruptured abdominal aortic aneurysm in one, and respiratory complications in one. Therefore, an excellent result was achieved in 97.2% of patients. With occlusion of the carotid artery for the endarterectomy, 165 patients (46%) had appreciable attenuation in intraoperative electroencephalographic findings and a decrease in cerebral blood flow to approximately 10 ml/100 g of brain tissue per min that necessitated placement of a shunt. This high percentage of profound electroencephalographic and blood flow changes during carotid occlusion suggests that the potential for collateral blood flow in this group of patients is minimal. These results demonstrate that a carotid endarterectomy can be performed at low risk in patients with a contralateral carotid occlusion. We advocate annual noninvasive carotid testing for patients with asymptomatic carotid stenosis and contralateral carotid occlusion. If progression of the stenosis is evident, a prophylactic endarterectomy should be considered because these patients may have a higher risk for cerebral infarction than do patients with a unilateral asymptomatic stenosis.