Surgical Outcomes of Transmastoid Facial Nerve Decompression for Patients With Traumatic Facial Nerve Paralysis

OBJECTIVE: To evaluate the facial nerve function and audiological results of delayed (by at least one month after the insult) transmastoid facial nerve decompression (FND) in traumatic facial nerve paralysis (FNP). METHODS: Medical records of 57 patients with traumatic FNP were reviewed and surgical results of 13 patients (mean age 28.0 ± 17.67, range 3-67) undergoing transmastoid FND were analyzed. Preoperative and postoperative mean hearing thresholds were compared using 0.5, 1, 2, and 3 kHz. Facial nerve function was graded according to the House–Brackmann scale (HB) before and after surgery. HB scale results of grade III or better were accepted as good results postoperatively. RESULTS: Preoperative HB grades were V in 5 and VI in 8 patients. Twelve of 13 patients had good recovery of facial nerve function regardless of the operation timing. When mean preoperative and postoperative air–bone gap (ABG) values were compared (except the patients with total sensorineural hearing loss), the mean preoperative ABG was 33 ± 15.9 dB, and mean postoperative ABG was 17.2 ± 8.68 dB. There was a mean hearing gain of 15.8 dB after transmastoid facial nerve decompression surgery. Surgery and anesthesia-related complications were not seen in any patients. CONCLUSION: The transmastoid route can be used safely and effectively with elimination of the risks of craniotomy and middle fossa surgery for patients with traumatic FNP. Hearing improvement can be achieved by performing ossicular chain reconstruction during decompression surgery for patients with conductive or mixed hearing loss (HL). KEYWORDS: : Facial nerve, decompression, facial paralysis