Persistent hypoglossal artery encountered during carotid endarterectomy.

The hypoglossal artery is present as an anastomotic channel between the carotid and vertebrobasilar system for approximately one week during embryologic development. Rarely, it may persist into adulthood and may be encountered during cerebrovascular operations. We report a 76-year-old woman with a persistent hypoglossal artery and a symptomatic internal carotid stenosis treated successfully by carotid endarterectomy. A discussion of the embryology, radiology, and operative pitfalls follows.