Hearing rehabilitation in congenital canal atresia

The purpose of this study was to review the results of our patients with congenital canal atresia after implantation of bone-anchored hearing aids (BAHA). The occurrence of complications was also reviewed.

This was a retrospective analysis of the first 16 patients who had BAHA implantation at Universiti Kebangsaan Malaysia Medical Centre, Malaysia. Audiometric assessment was done preoperatively and postoperatively for each patient using the standard procedure. The surgical procedure was described and its complications discussed.

The 16 patients consisted of 11 male and five female patients. Their mean age was 8.9 years at the time of the surgery. The main indication was bilateral canal atresia. 11 patients had implantation of BAHA performed in two stages, while the other five patients had it as a single-staged procedure. The complications that occurred were failure of osseointegration (one patient), granulation tissue overgrowth into the abutment (two patients) and cellulitis surrounding the abutment (three patients). The average preoperative unaided air conduction threshold was 64.9 dB and the average postoperative aided hearing threshold was 29.7 dB. The overall mean functional gain was 35.2 dB.

BAHA has many advantages over the conventional hearing aid in the form of cosmesis, discomfort and hearing gain. It is a reliable hearing rehabilitation tool with good predictable hearing outcome in patients with bilateral canal atresia, especially those unsuitable for canalplasty. Despite its higher cost and the need for surgical implantation, its use is justifiable in properly selected patients.