Extra-cranial branch of the internal carotid artery.

It has been argued in recent years that angiography is no longer essential before undertaking a carotid endarterectomy, relying solely on a carotid duplex scan. A case is presented where an extra-cranial branch of the internal carotid artery was found at surgery. This unexpected finding was obviated having obtained preoperative angiograms. Anomalies of the internal carotid artery are reviewed.