Fully endoscopic approach to cerebellopontine angle tumors: a systematic review and meta-analysis

The cerebellopontine angle (CPA) is a surgically complex region due to its dense neurovascular anatomy. Traditional microscopic retrosigmoid approaches provide limited visualization in deep recesses. The fully endoscopic retrosigmoid approach (FERA) has emerged as an alternative, offering panoramic views and potentially improved functional outcomes. However, its efficacy and safety remain incompletely defined. A systematic review and meta-analysis were performed following PRISMA guidelines. PubMed, Embase, Web of Science, and Cochrane Library were searched through February 2025. Eligible studies reported ≥ 5 patients undergoing CPA tumor resection exclusively with FERA. Data were synthesized using random-effects models, and outcomes included gross total resection (GTR), facial and hearing preservation, and perioperative complications. Risk of bias was assessed using the ROBINS-I tool. 11 studies comprising 282 patients (39.4% male; mean age 31-61 years) met inclusion criteria. Pathologies included 140 epidermoid cysts, 114 vestibular schwannomas, 18 meningiomas, and 21 other tumors. Pooled GTR was achieved in 85% (95% CI 74-92). Facial nerve preservation (House-Brackmann I-II) was 93% (95% CI 87-96), and serviceable hearing preservation (Gardner-Robertson I-II) was 73% (95% CI 49-88). One major complication (postoperative hemorrhage) was reported, while minor complications occurred in 14% of patients, predominantly cerebrospinal fluid leaks and transient neuropathies. Most studies demonstrated moderate risk of bias, with confounding and reporting heterogeneity as major limitations. FERA enables high resection rates with favorable facial nerve and hearing preservation, while maintaining an acceptable safety profile. Although current evidence supports feasibility, prospective comparative trials with standardized reporting are required to define its role relative to microscopic and endoscope-assisted techniques.