Bone-anchored hearing aids (Baha) in congenital aural atresia: personal experience

Aural atresia is a congenital disease constituted by partial or complete lack of development of the external auditory canal, which is generally associated with malformations of the auricle and middle ear. Reconstruction of the auditory canal and correction of any deformities of the middle ear have yielded unpredictable results and variable functional outcomes, and there is a high rate of complications. Therefore, the use of bone-conduction hearing aids, such as the Baha, may represent a valid alternative for subjects who have conductive hearing loss with cochlear reserve that, as a rule, is fully conserved. The aim of this work is to reexamine our experience with the management of conductive and mixed hearing loss using the Baha system in children with bilateral aural atresia.

We examined 31 patients with bilateral congenital aural atresia in whom a Baha system had been implanted. The patients, 16 males and 15 females, were between 5 and 14 years of age (mean 8.7). The following parameters were assessed for each patient: mean preoperative air and bone conduction for frequencies between 0.5 and 4kHz; mean preoperative threshold with conventional bone-conduction hearing aids; mean postoperative threshold with the Baha system; improvement in quality of life evaluated with the Glasgow Children's Benefit Inventory; rate and type of surgical complications.

The mean preoperative air- and bone-conduction thresholds were 51.2±12.5 and 14.1±6.3dB HL, respectively. The mean preoperative threshold with a conventional bone-conduction hearing aid was 29.3±7.2dB HL, and the mean postoperative threshold with the Baha system was 18.1±7.5dB HL. Quality of life improved for all operated patients.

The results of our study of the Baha system to treat patients with bilateral aural atresia were extremely satisfactory compared both with those of surgical reconstruction of the auditory canal and those of traditional bone-conduction hearing aids. Furthermore, great improvement was noted in quality of life, while the rate of complications was very low. Therefore, we are convinced that the Baha system is the treatment of choice for hearing loss due to bilateral congenital aural atresia.