(843) Endoscopic Assistance in Cerebellopontine Angle Epidermoid Cyst Resection: A Systematic Review and Meta-Analysis

Introduction: Resection of cerebellopontine angle (CPA) epidermoid cysts (EC) is challenging due to capsular adherence and limited visualization around critical neurovascular structures. We evaluated whether endoscopic assistance during microsurgical resection influences extent of resection, recurrence, and postoperative complications.

Methods: PubMed, Embase, and Web of Science databases were systematically searched for studies published between January 2000-November 2025 reporting surgical outcomes for CPA EC. Two reviewers independently screened studies, extracted data, and assessed study quality. Primary outcomes were extent of resection and recurrence, while secondary outcomes were postoperative complications. Pooled estimates were calculated using meta-analysis of proportions. Random-effects meta-regression compared endoscopic-assisted (EA) microsurgery with microsurgery alone (MS). Risk of bias was assessed using Joanna Briggs Institute critical appraisal tools.

Results: Of 642 articles screened, 29 studies (696 patients) met inclusion criteria. The pooled recurrence rate across all studies was 10.8%. Pooled complication rates included new or worsening deficits of CN V (1.8%), CN VII (8.5%), and CN VIII (8.0%) as well as postoperative CSF leak (2.8%), aseptic meningitis (4.7%), and hydrocephalus (0.7%). The pooled gross total resection (GTR) rate was 60% for MS and 81% for EA. Meta-regression demonstrated higher odds of GTR with EA compared to MS (OR 3.34, 95% CI: 1.31–8.51; p=0.011). Pooled recurrence was 0% after EA surgery versus 12% after MS.

Conclusions: Endoscopic assistance during microsurgical resection of CPA EC was associated with higher GTR rates and may reduce risk of recurrence. Thus, when clinically feasible, adjunctive endoscopy may improve surgical outcomes in CPA EC resection.