Natural history of symptomatic and asymptomatic carotid artery occlusion contralateral to carotid endarterectomy.

ABSTRACT Background The natural history of carotid occlusion (CO) has generally been analyzed in the presence of a contralateral patent but diseased internal carotid artery (ICA). Few previously published studies have focused on the fate of CO contralateral to the side of a prior carotid endarterectomy (CEA). We analyzed the mortality rate and the incidence of cerebrovascular events in the hemisphere ipsilateral to CO (HICO) in patients who had undergone contralateral CEA. Methods The study considered the perioperative (30-day) and long-term outcomes of 153 consecutive patients who had CEA for severe symptomatic and asymptomatic ICA lesions contralateral to a symptomatic or asymptomatic CO over a 15-year period at our institution. Patients were followed up by two neurologists and two neurosonographers who, respectively, performed a clinical examination and a cerebral duplex ultrasound scan at each visit. The end points of the study were mortality and neurological events in the HICO. Kaplan-Meier analysis was used to estimate the freedom from stroke in the HICO. The stroke-free survival rate was also calculated. Results Overall, the 30-day mortality and stroke rates were 0.6% (1/153) and 1.9% (3/153), respectively: the only death was stroke-related and the stroke was ipsilateral to the operated side. The other two strokes were both ipsilateral to a symptomatic CO. The follow-up was completed for all patients (mean, 7.7 years; range, 1-172 months). Overall, there were 4 late strokes (2.6%), one of them lacunar in a patient with a symptomatic CO, whereas the other 3 were atheroembolic and ipsilateral to the operated ICA. Kaplan-Meier analysis showed that freedom from late stroke in the HICO at 1, 3, 5 and 12 years was 98.7%, 98%, 98% and 98%, respectively. There were also 8 late transient ischemic attacks, 5 of them occurring in the HICO (4 in symptomatic and 1 in asymptomatic CO). Overall, there were 19 late deaths, none of them stroke-related. The stroke-free survival rates at 1, 3, 5 and 12 years were 98.7%, 91.8%, 85.5% and 65.5%, respectively. The only asymptomatic ≥ 50% restenosis detected during the follow-up was unassociated with any neurological events in the HICO. Conclusion CO, with or without symptoms, contralateral to CEA could be considered a locally benign condition in the long term. An excellent freedom from stroke was not translated into a longer survival in our patients, however, because late mortality never correlated with cerebrovascular events.