Facial Nerve Outcomes Following Microsurgical Resection of Large Cerebellopontine Angle Tumors: Experience From a Tertiary Care Center in Pakistan

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. MethodsThis 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. ResultsThis study analyzed 95 patients (M:F=1:1.16,mean age 44.24±13.71years) 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. ConclusionFacial 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.