両側内頸動脈欠損症に合併した破裂後交通―後大脳動脈瘤の1手術例

Ruptured P1-2 Junction Aneurysm Associated with Bilateral Agenesis of the Internal Carotid Artery

Ⅰ．は じ め に

　内頸動脈欠損症は稀な血管破格であるが，脳動脈瘤を合併し発見されることが多い^{1,15,18,19,23)}．欠損は通常，十分に発達した側副血行により代償されているが，hemodynamic stressのかかりやすい部位に脳動脈瘤が発生しやすいことによると考えられる．今回われわれは，両側内頸動脈欠損症に合併した破裂後交通─後大脳動脈瘤の1手術例を経験した．このような血管破格を伴った例における，手術の注意点と眼症状について述べたい．

　We report a case of bilateral agenesis of the internal carotid artery which was revealed by oclulomotor palsy and subarachnoid hemorrhage. Angiography showed a ruptured aneurysm of the left P1-2 junction and bilateral absence of the internal carotid artery.

　In surgery, it was necessary to use temporary clipping several times to adjust the aneurismal clipping. Complete clipping easily compromised the middle cerebral circulation. This case suggested that STA-MCA bypass should be considered in the surgery of agenesis of the internal carotid artery in which the preoperative hemodynamic status is usually normal.