Persistent trigeminal artery associated with intracranial arterial aneurysm.

Two patients with persistent trigeminal artery associated with a ruptured arterial intracranial aneurysm arising from the ipsilateral internal carotid artery at the level of the posterior communicating artery are presented. One patient underwent successful clipping of the aneurysm. The other patient died on the x-ray table shortly after admission during the performance of emergency carotid angiography. In each patient, the anomalous vessel was considered to be incidental.