���大脳動脈部分血栓化巨大動脈瘤（p2）の1治験例

We report a case of a partially thrombosed giant aneurysm on the right posterior cerebral artery successfully treated by proximal occlusion. A 42-year-old man was referred to our department for the treatment of a partially thrombosed giant aneurysm in the incidental right posterior cerebral artery. On admission, the patient had no neurological deficit. Cerebral angiogram revealed a giant aneurysm of the right P2 segment. CT scan with intravenous contrast medium injection showed “target” like enhanced mass at the right quadrigeminal cistern. A balloon occlusion test of the posterior cerebral artery failed due to difficult catheterization. After good filling of the posterior cerebral artery distal to the aneurysm by collateral flow was confirmed with intra-operative angiography, clip occlusion of the posterior cerebral artery was performed at immediately proximal to the aneurysm. The patient complained of visual field defect (left upper quadrantanopsia) 2 days after the operation. CT scan revealed a low-density area in the right temporal lobe. Post-operative angiograms revealed complete obliteration of the aneurysm and good filling of both parietooccipital artery and calcarine artery by collateral flow via posterior choroidal artery, and also showed poor filling of the right posterior temporal artery, which had caused infarction on the right posterior temporal lobe. Follow-up CT scan taken 12 months after the operation revealed disappearance of the aneurysm. At 36 months post-operation, the patient is working well at his prior office.