Orphaned Middle Cerebral Artery Side-to-Side In Situ Bypass as a Favorable Alternative Approach for Complex Middle Cerebral Artery Aneurysm Treatment: A Case Series.

OBJECTIVE:Middle cerebral artery (MCA) aneurysms have continued to be primarily managed microsurgically. In cases of complex MCA aneurysms, revascularization could facilitate effective aneurysm treatment. The MCA candelabra provides excellent candidates for in situ side-to-side bypass. In the present case series, we have described applications of MCA in situ side-to-side bypass for the management of complex MCA aneurysms, along with a review of the pertinent data. METHODS:A retrospective review of a prospectively maintained neurosurgical patient database was performed to identify all patients treated with MCA side-to-side in situ bypass. Six consecutive patients were identified and included in the present series, representing a single-surgeon experience from February 2016 to November 2018. RESULTS:Of the 6 complex MCA aneurysms, all were unruptured, and one half had been treated via a minipterional approach that also allowed for simultaneous anterior communicating artery aneurysm clipping in 1 case. The median temporary occlusion time for anastomosis was 33 minutes (interquartile range [IQR], 30.3-35 minutes). Bypass patency was confirmed in all cases both intraoperatively and postoperatively. The median hospitalization time was 4.5 days (IQR, 2-8 days). The median follow-up period was 5.5 months (IQR, 2.8-22.3 months). All patients had achieved excellent or good (≤1) modified Rankin scale scores at discharge and during the follow-up period. No mortalities occurred, and no technical, bypass-related, or ischemic morbidities had developed. CONCLUSIONS:Our experience with MCA side-to-side in situ bypass has demonstrated its safety and utility in complex MCA aneurysm management. The favorable anatomy of the MCA branches allows for minimally invasive revascularization and clipping that can potentially reduce the hospitalization time and incidence of perioperative morbidity.