Surgical Outcomes and Predictive Factor Analysis for Facial Nerve Preservation in Patients With Cerebellopontine Angle (CPA) Tumors: A Ten-Year Single Institutional Study

Objective To analyze the surgical outcome and predictive factors for facial nerve preservation in patients with surgically operated cerebellopontine angle (CPA) tumors. Methodology Methodology Data were retrospectively retrieved from inpatient medical records of patients admitted with CPA tumors from January 1, 2011, to December 31, 2020, at our institute. Epidemiological, clinical and radiological findings, histopathological types, surgical outcomes, and facial nerve function of these patients were recorded using a data-gathering tool. Results Out of 230 patients, 188 (81.7%) were diagnosed histopathologically with vestibular schwannoma (VS), 20 (8.7%) with meningioma, 15 (6.5%) with epidermoid, and 7 (3.1%) with other conditions. The most common clinical features were hearing loss in VS and headaches in meningioma and epidermoid. Preoperatively, 103 (44.8%) had grade 2, 68 (29.6%) had grades 3 or 4, and 8 (3.5%) had grade 5 facial nerve palsy, while post-operatively, 93 (40.9%) patients had grade 2, 83 (36.6%) had grades 3 or 4, and 6 (2.6%) had grade 5 facial palsy. Greater facial nerve preservation was observed in patients with tumor sizes <4 cm (p=0.0041) and in those who underwent near-total (NTR) or subtotal resection (STR) (p=0.0442). Excellent facial nerve outcomes (HB grades 1 or 2) were noted in patients who underwent intraoperative facial nerve monitoring (p<0.0001). CSF leak and meningitis were present in 3.5% and 2.2% of patients, respectively. The mortality rate was 6.1%, with a recurrence rate of 4.8%. Conclusion Intraoperative facial nerve monitoring, tumor size less than 4 cm, and extent of resection (NTR/STR) are predictive factors that significantly affect facial nerve outcomes.