Abstract
BACKGROUND: Cerebellopontine angle (CPA) tumors present surgical challenges due to their proximity to the facial nerve. Despite preservation efforts, facial nerve paresis is a major issue. This study aims to identify key factors affecting facial nerve preservation during microsurgical resection of large CPA tumors in a low- and middle-income countries (LMIC) setting. METHODS: This retrospective cross-sectional study, conducted at Aga Khan University, included patients who underwent microsurgical resection of large (>3 cm) CPA tumors with House-Brackmann (HB) grades 1-4. Postoperative facial nerve function was assessed using the HB grading system. Data was extracted from medical records and analyzed using SPSS 22. RESULTS: This study analyzed 95 patients (M:F=1:1.16, mean age 44.24±13.71 years) with CPA tumors who underwent microsurgical resection. Common presenting complaints included a complete hearing loss (57.9%), headache (52.6%), and abnormal gait (40%). Preoperative facial nerve function was normal (HB grade I) in 75%, with 19%, 7%, and 2% having HB grades II, III, and IV, respectively. Schwannoma (69.5%), meningioma (16.8%), and epidermoid cyst (10.5%) were the most common diagnoses. Postoperative preservation of facial nerve function was achieved in 73.7% of patients. At six months, HB grades I and II were observed in 64% and 11.5%, respectively, while none had complete facial nerve palsy. On univariate analysis, larger tumor size and higher HB grade correlated with worse facial nerve outcomes (p=0.02). Complications were more frequent in patients with worsened outcomes (72% vs. 38.6%, p=0.004). However, in multivariate analysis, only preoperative HB grade was identified as a predictor. CONCLUSION: Facial nerve preservation during CPA tumor resection is influenced by intrinsic tumor characteristics, surgical complexity, and patient-specific factors. Detailed preoperative counseling is crucial to set realistic expectations.