通常の後交通動脈および前脈絡叢動脈分岐部内頚動脈りゅう手術のｐｉｔｆａｌｌとその対策

Abstract

Internal carotid (IC) aneurysms arising from the bifurcation of the posterior communicating (Pcom.) and anterior choroidal (Achor.) arteries are common, but carry a risk of intraoperative massive bleeding and ischemia of perforators territory those the patients' outcome worse. Proximal flow control is important to reduce the risk of rupture aneurysms during dissection and clipping. The internal carotid artery of the supraclinoid portion is sometimes arteriosclerotic and inadequate to place the temporary clip. Therefore we sometimes perform proximal flow control at the cervical carotid artery. Use of the J-shape clip to avoid the origin of the perforating artery to be occluded and anterior temporal approach for the fundus of aneurysms projecting posterior are also useful. We investigated 135 consecutive aneurysm surgeries for the IC aneurysms arising from the bifurcation of the Pcom. and Achor. arteries as regard to the use of proximal flow control and occurrence of the ischemic complications in the perforators' territory. Proximal flow control was performed in 62 surgeries for ruptured aneurysms and 13 for un-ruptured aneurysms. In 40 of all 75 surgeries where proximal flow control was performed, the carotid artery was clamped at the extracranial cervical portion. The main reason for this was arteriosclerosis of the intracranial internal carotid artery to be clipped with temporary clips. Each occlusion time was less than 10 minutes in most cases. Infarction of the perforator territory occurred in 4 of 92 surgeries (3.7%) for ruptured aneurysms and in none of 43 surgeries for non-ruptured aneurysms. Proximal flow control is important for the safe treatment of usual IC aneurysms. Prevention of injury to the Achor. artery is also beneficial to a favorable outcome.