Awake microsurgical management of brain aneurysms: a comprehensive systematic review and meta-analysis on rationale, safety and clinical outcomes

•Awake microsurgical management of brain aneurysms appears to be tolerated for select cases.•Current evidence is limited and stems from observational studies.•Further research is warranted to assess judiciously its safety and preference over existing methods for intraoperative neurological monitoring. Awake microsurgery for brain aneurysm treatment has emerged as a tool for real-time intraoperative monitoring, opportune detection of ischemic complications, and reduction of surgical morbidity. Herein, we aimed to explore the current state of the procedure’s rationale, safety and clinical outcomes. In accordance with PRISMA guidelines, five databases were queried for articles reporting awake microsurgical management of brain aneurysms. Aggregate study results were combined using random-effects meta-analyses. Publication bias was evaluated through funnel plot analysis and Egger's regression test. Out of 847 articles, 11 records satisfied the inclusion criteria. Seventy-five patients (68% female) with 75 brain aneurysms (68% unruptured) were analyzed. Clipping was the predominant technique (58%), followed by bypass (17%). Monitored anesthesia care was the principal anesthesia protocol (60%). The incidence of anesthesia-related complications was 1% [95%CI, 0.00−0.05, I2 = 19%], and the conversion rate from an awake-induced anesthesia protocol to general anesthesia was 1% [95%CI, 0.00−0.05, I2 = 0%]. No permanent anesthesia-related morbidity and mortality was reported. Complete aneurysm repair, occlusion and bypass patency rate was 100% [95%CI, 0.96−1.00, I2 = 0%]. The transient postoperative symptomatic event rate was 34% [95%CI, 0.06−0.81, I2 = 77%]. The overall morbidity rate was 4% [95%CI, 0.00−0.09, I2 = 0%], and the overall mortality rate was 0% [95%CI, 0.00−0.03, I2 = 0%]. Awake microsurgery of brain aneurysms is feasible, yet current evidence stems from observational studies. This procedure can reduce surgical morbidity by providing accurate and real-time neurological monitoring during aneurysm repair. While this technique appears to be tolerated, higher level evidence is needed to evaluate judiciously its safety and preference over existing practices for intraoperative neurological monitoring.