Objectives: Canalplasty is a surgical procedure of the external auditory canal. In this study we examined anatomic risk factors for facial nerve injury in aural atresia surgery, in addition to facial nerve outcomes and the time course of recovery in patients with facial nerve palsy following atresia surgery.
Methods: Transient facial palsy was observed immediately after surgery in 6 of 99 ears (6 of 87 patients) after canalplasty and tympanoplasty for the treatment of congenital aural atresia. We assessed the course of recovery and mean scores using Jahrsdoerfer's grading system.
Results: The rate of absence of the stapes and the rate of presence of positional anomalies of the facial nerve were significantly higher among cases with facial palsy, and Jahrsdoerfer total scores were significantly lower among cases with facial palsy. The mean recovery time in 5 cases with a minimum electroneurography value of 0% was 16.2 weeks (range, 14 to 18 weeks). No trends during recovery were detected for the nerve excitability test and R1 components of the blink reflex.
Conclusions: The anatomic conditions that cause a predisposition to transient facial palsy include absence of the stapes and the presence of positional anomalies of the facial nerve. Although some patients displayed transient facial palsy after surgery, all patients fully recovered. Mechanisms of facial nerve injury are proposed.