Giant Multilocular Fusiform Aneurysm of the Posterior Cerebral Artery. Report of a Case Treated by Parent Artery Occlusion Together with Intra-aneurysmal Embolisation.

A 60-year-old woman presented with a giant posterior cerebral artery aneurysm. Her visual field examination revealed right upper quadrantanopia. Because of the difficulty of the neck clipping, we performed parent artery occlusion using the Guglielmi detachable coils following balloon Matas test monitored with single photon emission computed tomography (SPECT) with 99mTc-d, I hexamethyl-propylene-amine oxime. Postoperative left internal angiography showed the left occipital region was supplied by a leptomenigeal collateral via left the middle cerebral artery. Six months after embolisation the aneurysm was completely thrombosed on MR imaging. Her visual field deficits had also improved six months after embolisation. A combination of the balloon Matas test with SPECT followed by parent artery occlusion is an excellent method to treat such giant aneurysms.