シルビウス裂深部の正常異形静脈（common vertical trunk）の存在はshort M1中大脳動脈瘤clipping術に伴う虚血性合併症率を高める

抄録

Middle cerebral artery aneurysms (MCANs) associated with short M1 located in the limen insulae tend to have poor outcomes after surgical clipping due to brain contusions and ischemic complications. However, the effect of veins in the deep Sylvian fissure is unclear. The normal variant of the insular veins and deep middle cerebral vein, which runs anteriorly near the limen and drains into the sphenoparietal sinus, is known as the common vertical trunk (CVT). We retrospectively examined whether the presence of a CVT increased surgical complications after clipping of short M1 aneurysms in 164 cases of unruptured MCANs (153 patients) clipped by the same surgeon. The 21 aneurysms located proximal to the limen insulae were defined as short M1 aneurysms. The 164 patients were divided into a short M1 group (n=21) and a non-short M1 group (n=143). The short M1 group was further divided into a CVT group (n=6) and a non-CVT group (n=15). The short M1 group showed a significantly (p＜0.001) longer operative time and higher rates of lacunar infarction and symptomatic (modified Rankin score ≥1) infarction than the non-short M1 group. The CVT group had higher rates of lacunar infarction and symptomatic infarction (50.0% and 16.7%, respectively) than the non-CVT group (26.7% and 6.7%, respectively). The CVT obstructed the view of the aneurysm neck behind the CVT, where the lenticulostriate arteries were located. The presence of a CVT in cases of short M1 aneurysms may be a risk factor for ischemic complications after clipping surgery.