内頸動脈後向きの動脈瘤に対するtranssylvian approachの変法としてのanterior temporal approach

Because ventrally directing IC aneurysm is sometimes difficult to treat by the standard pterional approach, we attempted to modify our distal transsylvian approach. We describe this modified distal transsylvian approach (anterior temporal approach) in this paper. The surgical method comprises the following steps; 1. Superficial sylvian veins are displaced to the frontal side of the fissure without sacrificing those veins. An anastomotic trunk of the deep middle cerebral vein is dissected from the medial temporal lobe. 2. A posterior division of M2 segment, M1 segment and anterior temporal artery are dissected from the medial temporal lobe. 3. Arachnoid trabecula between the uncus and the anterior choroidal artery is incised. This allows posterolateral retraction of the temporal pole without significant retraction. Although the anterior temporal approach is employed for the surgical treatment of distal BA aneurysm, it is also available for the IC ventral aneurysm.