Basilar artery aneurysm treated with coil embolization via persistent primitive trigeminal artery.

A saccular aneurysm of the right basilar-superior cerebellar artery associated with a persistent primitive trigeminal artery (PPTA) was successfully treated by endovascular occlusion with Guglielmi detachable coils. Since both vertebral arteries and the basilar artery proximal to the junction with the PPTA were hypoplastic, a microcatheter was advanced via the PPTA. To our knowledge, this is the first case report describing the treatment of the aneurysm through the PPTA.