Influence of the contralateral carotid artery on carotid surgery outcome.

Background: Any obstacle in the contralateral artery has long been considered a high risk for carotid surgery. Here, we report the results of a monocentric, continuous, consecutive, prospective series and present a review of the literature. Methods: All carotid endarterectomies performed under locoregional anesthesia in our department between 2003 and 2010 were recorded in a prospective database (n = 1,212). Different statuses of the contralateral carotid artery-occlusion (group O, n = 81) and stenosis of >60% (group S, n = 173)-were compared with a control group (group C, n = 958). A shunt was used in cases of clinical intolerance to clamping. The assessment criteria concerned the need for a shunt and the combined 30-day nonfatal stroke and death rate. A stepwise logistic regression was performed. Results: Overall, a shunt was necessary in 7.3% of cases. The proportion was greater in group O (25.9%, P < 0.001). Severe renal insufficiency (odds ratio [OR] = 1.94) and contralateral carotid occlusion (OR = 5.53) were the sole factors predicting the need for shunting. The overall 30-day nonfatal stroke and death rate was 2.5%, with no difference between groups (P = 0.738), and severe renal insufficiency was the single predictor of a poor outcome (OR 3.11; 95% confidence interval: 1.21-7.97; P = 0.18). Conclusion: In this series, and in a large review of literature, occlusion of the contralateral internal carotid artery increased the incidence of intolerance to clamping and thus the use of shunts but did not worsen postoperative morbidity and mortality. The presence of a stenosed contralateral carotid was not predictive of postoperative events. In our experience, the status of the contralateral carotid artery cannot be considered a high risk for carotid surgery.