脳動脈瘤手術の体位と頭部固定における重要なポイントは？

Important Points for Patient Positioning and Head Fixation in Cerebral Aneurysm Surgery

Point

・スカルピン刺入部位は，前頭洞・側頭骨などの骨菲薄部や，頭皮の動脈や静脈洞の直上を避ける．

・頭部の回旋（rotation），頚部の屈曲・伸展（vertex up or down），側屈（tilt）の3要素を意識して頭位を決定する．

・頭部固定では，頭部を挙上し頭蓋内圧を下げ，頚部過屈曲による静脈還流障害を避ける．

　Patient positioning and head fixation are two of the most important aspects of cerebral aneurysm surgery. These procedures require an accurate understanding of the anatomy of the scalp and skull and of the process for approaching aneurysms. We describe the basics of this procedure in frontotemporal craniotomy, which is most frequently used in cerebral aneurysm surgery, with a focus on head fixation using the MAYFIELD three-pin skull clamp（Integra LifeSciences）.

　The insertion sites of the head pins should be avoided in areas with thin bone, such as the frontal sinus and temporal squama, and just above the arteries of the scalp and venous sinuses. The position of the head should be determined based on three factors：rotation, vertex up or down, and tilt. The head should be elevated to reduce intracranial pressure, and cervical hyperflexion should be avoided to prevent increased venous pressure.