Comparison Between Endoscopic and Microsurgical Fenestration for Subarachnoid Cysts: A Systematic Review and Meta-Analysis

Abstract Intracranial arachnoid cysts are cerebrospinal fluid–filled lesions present in 1.2–1.4% of the population. They are often asymptomatic but may cause headache, seizures, deficits, or hydrocephalus. Surgery is indicated in symptomatic cases, yet the optimal technique—endoscopic fenestration or microsurgery—remains debated. To compare efficacy and safety of endoscopic fenestration versus microsurgery for symptomatic intracranial arachnoid cysts through systematic review and meta-analysis. PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched up to March 2024, following PRISMA 2020. Comparative studies reporting cyst volume reduction (>50%) or postoperative complications (hematoma, cranial nerve palsy, mortality) were included. Data were analyzed with Review Manager 5.4 and R. Pooled relative risks (RR) with 95% confidence intervals (CI) were calculated using Hartung-Knapp adjustments and Paule-Mandel variance. Publication bias was assessed with funnel plots and Egger's test. Sixteen studies (1,157 patients; 596 endoscopic, 561 microsurgery) were included. Eight studies (n = 441) showed no significant difference in cyst reduction (RR = 0.92; 95% CI: 0.77–1.10; p = 0.325; I2 = 63.4%). Twelve studies (n = 716) suggested fewer hematomas with endoscopy, though not significant (RR = 0.61; 95% CI: 0.32–1.17; p = 0.139; I2 = 0%). Cranial nerve palsy was rare (<3%), and no mortality was reported. Endoscopic fenestration and microsurgery provide similar efficacy and safety. Choice should be guided by cyst anatomy and surgeon expertise. Further randomized trials are warranted.