脳底動脈分岐部動脈瘤に対する zygomatic approach

抄録

Based on our experience with 35 operations using the zygomatic approach for aneurysms on and around the basilar tip, we discuss the advantages, disadvantages, and the indications for this approach. Vertex down positioning of the patient's head, the skin incision just in front of the tragus extending 1.5 cm below the lower border of the zygomatic arch, the cranio-zygomatic osteotomy technique, and multi-directional approach with the rotatable head holder are all demonstrated by video. The bridging vein coming off the temporal lobe tip is cut, and either the anterior temporal or subtemporal route is used to approach the interpeduncular cistern. The posterior communicating artery is elevated in most cases, but working space is also obtained through the perforators coming off this artery. The only disadvantage is that it takes the surgeon 15 to 20 minutes longer than with the conventional craniotomy technique. The advantages of this approach are as follows.
1. The lowest possible supratentorial approach to high placed aneurysms on and around the basilar tip. 2. Working space is wide enough and the clip application is in multiple directions. The zygomatic approach is indicated not only for high placed basilar tip aneurysms, but for large or difficult aneurysms on and around the normal placed basilar tip. This approach, however, is not indicated for low placed basilar tip aneurysms. In the venous phase of angiography, the Rosenthal vein represents a rough configuration of the tentorial edge. In choosing an appropriate surgical approach, how high the tentorial edge is placed is as informative as the distance between the aneurysm neck and the posterior clinoid process.