Long-term complications of bone-anchored hearing aids: a 14-year experience

Objectives: To report cases of long-term surgical complications, implant failure and revision surgery, within a large bone-anchored hearing aid programme. Study design: Retrospective, case-cohort study. Setting: Tertiary referral centre. Patients: One hundred and sixty-five adults and children who had undergone a total of 177 bone-anchored hearing aid implantations. Intervention: Diagnosis and explanation of adverse events and device failure. Main outcome measures: Operative complications and survival analysis, surgical challenges related to revisions, and causes of failure. Results: Twenty-one per cent of patients (3.4 per cent of those observed) suffered from skin reactions; this rate did not increase over time. Seventeen per cent had loss of osseointegration at a median interval of 6.3 months. Loss of osseointegration was observed more frequently in patients with a 3 mm compared with a 4 mm fixture (p < 0.001.). Intra-operatively, the only complication was bleeding, occurring in 3 per cent of patients. Post-operative complications included: primary bleeding (2 per cent); severe skin reactions requiring intravenous antibiotics, cautery or grafting (8 per cent): thickening or overgrowth of skin requiring excision (8 per cent); failure of osseointegration requiring a new fixture (18 per cent); and graft necrosis requiring revision (I per cent). In two patients, it was necessary to explore the area to remove overgrowth of bone. In 16 patients (10 per cent), the bone-anchored hearing aid had to be abandoned due to failure of osseointegration (n = 4), dissatisfaction with the aid (n = 6), intolerable pain (n = 4), hair growth around the abutment (n = 1.) or recurrent infections (n = 1). In 12 of these patients, the bone-anchored hearing aid was removed surgically. Overall, 57 patients (34 per cent) underwent revision surgery. Conclusion: Awareness of complications is becoming increasingly important in bone-anchored hearing aid programme. A substantial workload of device maintenance should be anticipated, and patients should be appropriately counselled beforehand. Ninety per cent of our patients chose to persevere with this form of hearing rehabilitation.