Carotid endarterectomy in rare bilateral carotid-vertebral anastomosis

In the embryo, the anterior and the posterior cerebral circulations are con nected by several longitudinal anastomotic vessels. These anastomoses disap pear progressively, until the carotid and vertebrobasilar systems are conne cted only by a pair of posterior communicating arteries. These embryonal an astomoses rarely persist in adults and may have an important physiologic ro le during carotid surgery. We report a case in which a patient with bilater al embryonal carotid-vertebral underwent right carotid endarterectomy for a symptomatic internal carotid stenosis.