Long-term results with the titanium bone-anchored hearing aid: the U.S. experience.

OBJECTIVE: The purpose of this study is to evaluate the long-term safety and efficacy of the titanium bone-anchored hearing aid (BAHA).

STUDY DESIGN: A retrospective review of 24 patients implanted with the BAHA between 1984 and 1987 in a multiinstitutional study designed to evaluate the device in the United States was performed, including detailed clinical and audiologic evaluations of the 10 patients implanted at the Columbia-Presbyterian Medical Center in New York. The data were collected from patients' charts, questionnaires, and the Nobel Biocare patient contact and repair records.

PATIENTS: Candidates for the BAHA are unable to use a conventional air conduction hearing aid because of congenital aural atresia, draining mastoid cavities, or recurrent otitis externa. The audiologic indications are a conductive or a mixed hearing loss with a bone conduction average of 45 db or better and a speech discrimination score of 60% or better.

INTERVENTION: A BAHA was implanted in a two-stage procedure under local anesthesia on an outpatient basis.

MAIN OUTCOME MEASURES: Patients' satisfaction with the device, hearing improvement, and complication rates were reviewed.

RESULTS: The majority of the patients analyzed (78%) are still using the device an average of 15.6 hours/day 10 to 13 years after implantation. The overall satisfaction score was 4.5 (1, worst; 5, best). In sound field testing, the mean speech reception threshold improved from 52 db to 27 db (p < 0.05). There were no major complications.

CONCLUSION: The BAHA is a safe and effective bone conduction hearing aid with wide applications for patients with bone conduction hearing levels of 45 db and discrimination scores of 60% or better.