未破裂脳動脈瘤に対するpterional approachの低侵襲手術(<特集>脳動脈瘤-低侵襲手術) A Less Invasive Pterional Approach to an Unruptured Cerebral Aneurysm(<topics>Less Invasive Surgery for Cerebral Aneurysm)

Sacrifice of the bridging veins and/or inappropriate brain retraction may result in postoperative brain damage associated with the pterional approach to an unruptured aneurysm. We report a less invasive pterional approach preserving the bridging veins without the use of brain retractors in 104 patients with unruptured aneurysms (112 pterional approaches). The bridging veins from the frontal lobe to the superficial sylvian vein (SSV) were successfully preserved by 3 types of dissection of the sylvian fissure based on the preoperative stereoscopic carotid venogram (lateral and right oblique view): Type I, dissection on the frontal side of SSV (conventional method) in 47 approaches, including 17 approaches that were not related to SSV; Type II, dissection between SSVs in 31 approaches; Type III, dissection on the temporal side of SSV in 34 approaches. A wide operative view preserving the bridging veins without brain retractors contributes to the safe dissection and clipping of an unruptured aneurysm, preserving the parent arteries and perforators.