Coil embolization of an aneurysm located at the trunk of the persistent primitive trigeminal artery.

A 71-year-old woman presented with an aneurysm at the trunk of the persistent primitive trigeminal artery (PPTA) manifesting as subarachnoid hemorrhage. Angiography and three-dimensional computed tomography revealed a wide-necked saccular aneurysm at the trunk of the left PPTA. Coil embolization with the balloon-assist technique was successful and PPTA patency was preserved. Preoperative conventional angiography should be performed to check for cross-filling of the PPTA. This case demonstrates that an aneurysm of the trunk of the PPTA can be successfully treated by coil embolization using the balloon-assist technique.