内頚動脈分岐部動脈瘤直達手術後の穿通枝障害

Perforating Artery Injury during Microsurgery for Internal Carotid Artery Bifurcation Aneurysms

Ⅰ．はじめに

　内頚動脈分岐部動脈瘤（internal carotid artery bifurcation aneurysm：ICB-AN）は周囲に多数の穿通枝が存在し，それらを障害することなく完全な頚部クリッピング術を行うことは容易ではない．また，内頚動脈分岐部は動脈瘤好発部位の1つではあるが，その発生頻度は2〜10%と多く経験される部位ではなく^7,11,14,22)，その直達手術における穿通枝障害（perforating artery injury：PAI）について検討した報告は少ない．われわれは，当院で経験したICB-AN直達手術例における穿通枝障害について後方視的に検討を行ったので報告する．

　Internal carotid artery bifurcation aneurysms（ICB-ANs）are relatively rare and are difficult to occlude by direct clipping without perforating artery injury（PAI). We retrospectively analyzed 11 aneurysms in 10 cases. PAI was identified in 5 of 10 cases on postoperative computed tomography（CT）or magnetic resonance imaging（MRI), and 2 of these patients were symptomatic. PAIs were distributed in the caudate nucleus and/or the genu of the internal capsule. PAI occurred in 3 of 5 cases in which indocyanine green videoangiography（ICG-VAG）was performed. ICG-VAG is a helpful tool visualizing blood flow of vessels in surgical fields. However, PAI is a potential risk in direct clipping of ICB-ANs even if adjacent perforating arteries were observed using ICG-VAG.