内頚動脈-前脈絡叢動脈分岐部脳動脈瘤に対する治療—治療方法と虚血合併症について

Ischemic Complications of Anterior Choroidal Artery Aneurysm Treatment

Ⅰ．はじめに

　内頚動脈-前脈絡叢動脈（anterior choroidal artery：AChA）分岐部脳動脈瘤（AChA動脈瘤）は頭蓋内脳動脈瘤の2〜5%とされ¹⁾高頻度に発生する脳動脈瘤ではないが，AChAの支配領域が内包後脚を含む重要部位であるために，その血流障害は重篤な神経症状をもたらすことが多い．そのためAChA動脈瘤の治療においてはAChAの温存に注意が払われてきたが，最近の報告でも外科的治療後にAChA領域の梗塞を12〜22.6%に起こすとされ^1-3,9)，他部位の脳動脈瘤治療と比較して術後脳梗塞の頻度が高い．今回われわれはAChA動脈瘤の治療症例を検討して，治療方法とAChA領域の虚血合併症についての問題点を検討し報告した．

　Ischemic stroke of the anterior choroidal artery（AChA）is the most common and serious complication after AChA aneurysm treatment. The purpose of this study was to retrospectively evaluate and compare the treatment-related ischemic complications after surgical clipping and endovascular coiling of AChA aneurysms.

　Between June 2006 and March 2013, 32 patients with 34 AChA aneurysms were treated in our hospital by surgical clipping or endovascular coiling. There were 12 cases of ruptured aneurysms, seven cases of unruptured aneurysms, and 15 cases of incidentally identified unruptured aneurysms. Of the 34 aneurysms, 19 were managed with surgical clipping and 15 were managed with endovascular coiling. No rebleeding or retreatment occurred in any case during 4-84 months（median, 25 months）of follow-up, and no significant differences in clinical outcome were seen between clipping and coiling cases. Although there were four cases（11.8%;surgical clipping in three;endovascular coiling in one）of postoperative AChA infarction, we believe that we preserved the blood flow of the AChA during the procedure. The occurrence of subarachnoid hemorrhage and premature rupture during surgical clipping were significantly correlated with AChA infarction.