Iatrogenic facial nerve injury in mastoidectomy: The impact of variables on the outcome.

Objective: To evaluate iatrogenic facial nerve injury in mastoidectomy and its paralysis improvement result after nerve injury management.

Methods: A retrospective review of medical records of 21 patients with iatrogenic facial nerve injury following mastoidectomy who underwent nerve injury management in a tertiary referral center.

Results: There were nine males and 12 females, with a mean age of 40.4 ± 15.1 years. Cholesteatoma was the most common primary pathology (76.2%). Mastoidectomy was canal wall up in 8 patients and canal wall down in 13. Nerve injury was due to drilling in 10 patients and sharp tools in 11. The tympanic segment of the facial nerve was the most common injured site (50.0%). Decompression was the most common nerve injury management method (52.4%). Other injury management methods were end-to-end anastomosis (14.3%), great auricular nerve graft (23.8%), and facial-hypoglossal nerve transfer (9.5%). No statistically significant correlation was found between facial nerve function 3-6 months after injury management and the following factors: age, gender, primary pathology, type of mastoidectomy, surgeon's experience, nerve injury site, mechanism of trauma, and nerve injury management method and timing.

Conclusion: Regardless of the surgeon's experience or technique applied, a meticulous approach may be more valuable in decreasing the chance of iatrogenic facial nerve injury.