Long-term results and experience with the first-generation semi-implantable electromagnetic hearing aid with ossicular replacement device for mixed hearing loss

OBJECTIVE: To document the long-term surgical and audiologic results of the implantation of a first-generation semi-implantable hearing aid for mixed hearing loss, consisting of a magnetic partial or total ossicular replacement prosthesis and an electromagnetic driver fitted in the ear canal. The short-term results have previously been published as excellent in both surgical and audiologic terms. To analyze and discuss reasons of treatment failure, as well as future perspectives.

STUDY DESIGN: Patient file review, follow-up otomicroscopic examination and audiometry, as well as patient interview. SETTING Tertiary referral center at a University hospital.

PATIENTS: Of nine patients operated on, six with a mixed hearing loss after chronic otitis media could be evaluated primarily. Two underwent implantation with a partial and four with a total ossicular replacement prosthesis.

MAIN OUTCOME MEASURES: Use of and satisfaction with the hearing aid, apparatus function and integrity, hearing without electromagnetic driver, prostheses containment, drum abnormalities, nonaudiologic ear symptoms, e.g., discharge.

RESULTS: All patients attended follow-up for a mean of 9.5 years after implantation (range 8.8-10 years). No patients used the semi-implantable hearing aid at follow-up. The mean semi-implantable hearing aid using time was 24 months (range 3-60 months). The main reasons for discontinuation of use were problems fitting the electromagnetic driver correctly in the ear canal and prosthesis extrusion or dislocation.

CONCLUSIONS: Despite excellent short-term surgical and audiologic results, it is concluded that these first long-term results of the first-generation electromagnetic semi-implantable hearing aids with ossicular replacement prosthesis for mixed hearing loss are disappointing. However, improvements in the surgical approach and in the reshaping, refinement, and overall improvement of the semi-implantable hearing aid could lead to satisfactory treatment of this group of patients.