Prevention of cranial nerve injuries during carotid endarterectomy

Abstract

Injury to the cranial nerves extending through the operative field or in areas adjacent to it costitutes a local complication of carotid endarterectomy. We present basic data on the anatomy and most frequent causes of injury to the individual nerves and describe a method for preventing cranial nerve injuries during carotid endarterectomy. Using this method resulted in injury to one or more cranial nerve in only 11 (8.3%) of 133 consecutive carotid endarterectomy patients treated at the National Cardiovascular Center from 1991 to 1996. Only 1 (0.75%) injury of the recurrent and superior laryngeal vagal nerve was permanent and the others were transient. The transient injuries included 2 (1.5%) injuries of the hypoglossal nerve, 8 (6.0%) of the recurrent and/or superior laryngeal vagal nerve causing ipsilateral vocal cord paralysis, and 2 (1.5%) of the marginal mandibular branch of the facial nerve. Cranial nerve injury was not related to patient age or sex, symptoms, shunt usage, or bilateral surgery. However, it was more frequent in patients in whom the lesion reached the C2 or higher level. In our series of patients, the incidence of cranial nerve injuries during carotid endarterectomy was less frequent than usual and the vast majority were reversible. A thorough knowledge of topography and anatomy, combined with a cautious operative technique, should lower the incidence of cranial nerve injury during carotid endarterectomy.