Minimally invasive versus open surgery for the management of intradural extramedullary tumors: a systematic review and meta-analysis

PURPOSE: Minimally invasive surgery (MIS) has been adopted for intradural extramedullary (IDEM) tumors resection to reduce access-related morbidity associated with open surgery (OS). Whether these tissue-sparing corridors preserve oncologic adequacy and intradural integrity while improving perioperative efficiency remains uncertain. This study compared MIS and OS for IDEM tumors across morbidity, resection quality, and recovery outcomes. METHODS: A PRISMA-guided systematic review and meta-analysis was conducted. PubMed, Embase, and CENTRAL were searched to 1st December 2025 for comparative studies of MIS versus OS in adults with IDEM tumors. MIS was performed through tubular retractor or non-tubular mini-open and microsurgical hemilaminectomy corridors. Primary outcomes were overall complications, gross total resection (GTR), operative time, and blood loss. Secondary outcomes included cerebrospinal fluid (CSF) leak, wound infection, recurrence, reoperation, instability requiring fusion, and length of stay (LOS). Random-effects meta-analysis using restricted maximum likelihood estimation generated pooled risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs). Risk of bias was assessed using ROBINS-I and certainty using GRADE. RESULTS: Twenty retrospective studies comprising 1471 patients (MIS 691; OS 780) with a mean follow-up of 49.7 months were included. MIS was associated with fewer overall complications (6.7% versus 15.9%; RR 0.50, 95% CI 0.33-0.76; P < 0.001). GTR was comparable (93.1% versus 89.3%). MIS reduced operative time (MD - 25.6 min), blood loss (MD - 144.1 mL), and LOS (MD - 72.3 h), with substantial heterogeneity. No significant differences were observed in CSF leak, recurrence, reoperation, and wound infection. Instability requiring fusion was less frequent after MIS but did not reach statistical significance. Tubular MIS demonstrated consistent morbidity reduction than non-tubular approaches. CONCLUSION: For appropriately selected IDEM tumors, MIS achieves resection durability comparable to OS while reducing perioperative morbidity and recovery burden. These findings support a morphology-contingent, tissue-sparing approach rather than routine maximal exposure.