短期間に増大しコイル塞栓術を行った前脈絡叢動脈末梢部に発生した破裂脳動脈瘤の1例

Endovascular Coil Embolization for a Ruptured Distal Anterior Choroidal Artery Aneurysm Showing Definite Short-Term Enlargement: A Case Report

Ⅰ．はじめに

　前脈絡叢動脈に発生する脳動脈瘤は通常，内頚動脈との分岐部に発生し脳動脈瘤全体の5%以下の頻度である^5,16,28)．特に前脈絡叢動脈末梢部に発生する脳動脈瘤は非常に稀であり，治療時期や方法は定まっていない^4,10,21,27)．今回われわれは，中大脳動脈起始部の動脈硬化性閉塞に起因した前脈絡叢動脈末梢部に発生した破裂脳動脈瘤が短期間に増大し，血管内塞栓術で根治を得た1例を経験したので文献的考察を加えて報告する．

　Distal anterior choroidal artery aneurysms are quite rare, and appropriate treatment timing and methods remain unclear. Direct surgery of these aneurysms is difficult due to their deep location, small size, and angioarchitecture;however, pseudoaneurysms might disappear spontaneously with conservative treatment. A 65-year-old man with a history of hypertension was admitted to our hospital with a 5-day history of sudden headache and nausea. Computed tomography revealed an intraventricular hematoma located mainly in the right lateral ventricle. Cerebral angiography 7 days after onset revealed a right distal anterior choroidal artery aneurysm and proximal right middle cerebral artery occlusion caused by atherosclerotic changes. Endovascular coil embolization was performed under general anesthesia 14 days after onset. Preoperative angiography demonstrated definite enlargement of the aneurysm and stasis of the contrast agent in the aneurysm in the venous phase. Detachable platinum coils were delivered into the aneurysm and parent artery. The patient was discharged neurologically intact after the procedure. Follow-up angiography 3 months after coil embolization showed complete occlusion of the aneurysm. In recent years, endovascular surgery has emerged as a less invasive treatment option. Early treatment should be considered for patients with ruptured distal anterior choroidal artery aneurysm because these aneurysms might grow and re-rupture in the short term.