Carotid-cavernous sinus fistula caused by rupture of a primitive trigeminal artery aneurysm. Case report.

A case is reported in which an aneurysm arising at the junction of the right internal carotid artery and a persistent primitive trigeminal artery ruptured to form a carotid-cavernous fistula. The internal carotid artery was ligated without any signs of brain-stem ischemia due to inverted blood flow through the primitive trigeminal artery.