Prognostic Factors in Severe Post-Traumatic Facial Paralysis: Analysis of Outcomes Following Transmastoid Nerve Decompression

Abstract

Introduction: Post-traumatic peripheral facial paralysis is a significant therapeutic challenge in otorhinolaryngology and cervicofacial surgery, predominantly caused by temporal bone fractures from high-energy trauma like road traffic accidents. This study aimed to identify clinical, paraclinical, and intraoperative prognostic factors influencing functional outcomes following transmastoid facial nerve decompression for severe cases. Materials and Methods: A single-center, retrospective analytical study was conducted over ten years (2014-2023) at a tertiary care hospital. It included 44 consecutive patients with severe post-traumatic facial paralysis (House Brackmann grades 4-6) who underwent transmastoid decompression. Inclusion required CT-confirmed temporal bone fracture and EMG-documented nerve degeneration ≥90%. Data on demographics, clinical presentation, preoperative investigations (audiometry, EMG, CT), intraoperative findings, and 12-month outcomes were analyzed. Patients were stratified into good (HB 1-2) and fair/poor (HB 3-4) outcome groups for prognostic analysis using Chi-square and t-tests (p<0.05 significant). Results: The cohort was predominantly young males (mean age 27.1 years; 79.5% male). Road traffic accidents were the leading cause (77.3%). The mean delay to surgery was 12.0 ± 7.7 weeks. The most common intraoperative findings were nerve edema (68.2%) and fibrosis (20.5%), primarily in the tympanic segment (84.1%) and geniculate ganglion (63.6%). At 12 months, 54.5% of patients achieved a good outcome (HB 1-2). Univariate analysis identified the type of intraoperative nerve lesion as the sole significant prognostic factor (p=0.009), with fibrosis, granuloma, and ecchymosis predicting worse outcomes. No significant associations were found with age, sex, surgical timing, initial paralysis grade, or fracture type. Discussion: Our findings confirm the efficacy and safety of transmastoid decompression for severe post-traumatic facial paralysis. The strong association between intraoperative lesion type and functional outcome suggests that the histological nature of the nerve injury is a more critical prognostic determinant than timing alone in carefully selected patients. These results highlight the importance of a meticulous preoperative workup and intraoperative assessment to guide prognosis and management.