内頸動脈閉塞を伴う巨大脳底動脈先端部近傍動脈瘤の外科治療  [in Japanese] Surgical Treatment of Giant Basilar Tip Aneurysms with Unilateral Internal Carotid Artery Occlusion  [in Japanese]

雑誌掲載版一側内頸動脈閉塞に伴い脳底動脈及びその近傍に生じた巨大動脈瘤の4症例(症例1;69歳女性動・脈瘤径13mm大、症例2;54歳男性・25mm大、症例3;65歳女性・30mm大、症例4;55歳女性・25mm大)を呈示し解説した。治療は全例でhemodynamic stressを軽減し血流の改善目的で内頸動脈閉塞側にEC-RA-M2 bypass術施行後にクリッピングを行った。クリッピングに際しては全例で脳底動脈先端部とその近傍が広く展開できるanterior temporal approach用い、母動脈の確保は問題なく行えた。内頸動脈閉塞側とクリッピング側が異なる症例4は二期的手術を行ったが他の3例では一期的に手術を行った。予後では、症例3で術後10年目にもともと血管拡張がみられた脳底動脈先端部に動脈瘤を生じ現在徐々に増大を続けており、不完全クリップに終わった症例4は、再手術の同意が得られず術後4年目にクモ膜下出血にて死亡した。以上より、巨大動脈瘤に対して橈骨動脈を用いて血行再建後にクリッピングを行い当初は良好な成績が得られたが、長期間の注意深い経過観察が必要と考えられた。

We report 4 cases of giant aneurysms in the basilar tip region, comprising 1 large and 3 giant aneurysms located in the basilar tip (2 cases), basilar-SCA (1 case), and PCA (1 case). One of the 4 was ruptured (basilar tip aneurysm). The symptoms were headache (3 cases) and oculomotor palsy (1 case; basilar-SCA). All aneurysms had unilateral internal carotid artery occlusion. In all cases the aneurysms were clipped following EC-RA-M2 bypass to prevent ischemia at the area of the occluded internal carotid artery and to reduce hemodynamic stress within the aneurysm. The clinical courses of 2' basilar tip aneurysms were good but 1 basilar-SCA aneurysm re-grew and ruptured 4 years later after incomplete clipping of the aneurysm. In 1 PCA aneurysm a new basilar tip aneurysm occurred that grew progressively. We consider that the cause of these aneurysms was hemodynamic stress due to internal carotid artery occlusion. It is suggested that the internal carotid artery should not be occluded without an EC-RA-M2 bypass.