Congenital aural atresia: bone-anchored hearing aid vs. external auditory canal reconstruction

Abstract

Objective: To compare the audiologic outcome and feasibility of bone-anchored hearing aid (BAHA) and external auditory canal reconstruction (EACR) surgeries in pediatric patients presenting a congenital aural atresia (CAA).

Methods: A retrospective chart review of 40 patients operated in our tertiary pediatric care center between 2002 and 2010 was performed. 20 patients underwent EACR, whereas another 20 patients were implanted with a BAHA device. Air conduction (AC), bone conduction (BC), pure tone average (PTA) and speech discrimination score (SDS) were compared preoperatively, and hearing gain (HG) postoperatively at 6 and at 12 months at frequencies of 500, 1000, 2000 and 4000 Hz. Operative time, complications and associated microtia were documented as well. EACR patients were graded retrospectively upon Jahrsdoerfer's classification.

Results: Preoperative AC were significantly different between groups, at 500, 1000 and 2000 Hz but not at 4000 Hz. BAHA group compared postoperatively to EACR group showed significantly a superior HG of 46.9 ± 7.0 dB (p<0.001) and of 39.8(7) ± 7.2(6.9)dB (p<0.001) at 6 months and at 1 year, respectively. Moreover, aided air thresholds from the EACR group revealed an audiologic status similar to those of the BAHA group patients, at 6 months and one year postoperatively. Both groups had a similar evolution of their BC, as well as of the incidence of complications. We report one case of transient facial paralysis in the EACR group. Total operative time is significantly lower (p<0.001) for a BAHA implantation (56 ± 21 min) than for EACR surgery (216 ± 174 min). No preoperative or postoperative correlation (Pearson correlation test; p>0.05) was found between patient's Jahrsdoerfer's score and their audiologic outcome. HG does not seem to be influenced by the presence of microtia.

Conclusion: EACR, although constituting an attractive option, does not give acceptable results alone. It can however, when combined to conventional air conduction hearing aids, provide excellent audiologic outcomes comparable to BAHA. BAHA implantation is a reliable, safe and efficient therapeutic option that allows a significantly better audiologic outcome when compared to unaided EACR for patients with CAA.