Anomalous Facial Nerve in Congenital Stapes Fixation

Abstract

The aim of this article was to assess the prevalence and influence of anomalous facial nerves in patients undergoing surgery for congenital stapes anomalies. The medical records of all patients who underwent surgery for congenital stapes fixation between January 1999 and December 2012 were retrospectively reviewed. An abnormal facial nerve was found in 7 ears in 5 patients (from a total of 62 ears). The patients' temporal bone computed tomography results, operation records, video clips, and preoperative and postoperative hearing tests were reviewed. Oval window atresia was found in all 7 ears, and the facial nerves in all 7 ears ran inferior medially over the atretic oval window niche. The atretic plate was fenestrated into the vestibule in the superior margin of the facial nerve. A piston wire was anchored to the long process of the incus in 3 ears, to the handle of the malleus in 3 ears, and attached to the tympanic membrane in 1 ear. The postoperative ABG at long-term follow-up was 13.1 dB (SD, 4.6 dB; range, 8.8-18.3 dB). No patient had postoperative facial weakness. An anomalous facial nerve was found in 11.2% of ears in patients undergoing surgery for congenital stapes fixation. Despite the anomalous course of facial nerves in these patients, vestibular fenestration was successful without facial nerve damage. The audiometric outcome at long-term follow-up was serviceable hearing for all cases.