Safety and efficacy of endoscopic and microscopic techniques for facial nerve decompression after trauma: a systematic review and meta-analysis

Background Facial nerve palsy (FNP) is a result of facial and temporal trauma, often requiring surgery. Endoscopic or microscopic nerve decompression is one of the main surgical treatments. However, robust evidence on the safety and efficacy of these techniques remains scarce in the literature. This systematic review and meta-analysis aimed to synthesize current data on the outcomes of these surgical techniques for traumatic facial nerve palsy (tFNP). Methods Following PRISMA guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library. Studies included patients who underwent endoscopic or microscopic surgical treatment for tFNP. Outcomes were classified by the House-Brackmann (HB) score: complications after surgery, normal facial function to recovery from mild dysfunction, moderate to moderately severe dysfunction, and severe dysfunction to total paralysis after surgery. Analyses were conducted separately, with subanalyses for the transmastoid (TM), middle cranial fossa (MCF), and combined TM+MCF routes in studies reporting. Results 26 studies with 597 patients were included. Overall complication rate was 2% for endoscopic and 3% for microscopic. Endoscopic outcomes showed HB I-II 88%, HB III-IV 6% and HB V-VI 3%. Microscopic revealed HB I-II 66%, HB III-IV 29% and HB V-VI 2%. The complication rates for the TM approach were 0%, MCF and TM+MCF combined were 3% and 2%. Furthermore, the HB I-II score rates were 66% (TM), 70% (MCF), and 58% (TM+MCF). Conclusion Both techniques are safe and effective, better efficacy was analysed with endoscopic. Further studies with standardized populations are needed.