Outcome and Complications after Implantation of the Bone-Anchored Hearing Aid in Patients Treated with Radiotherapy to the Temporal Bone

Background: The Bone-Anchored Hearing Aid (BAHA) is a prosthesis implanted in the temporal bone that transmits sound waves to the cochlea by direct bone conduction. BAHA is beneficial for patients with maximal conductive hearing loss following lateral temporal bone resection or skull base resection and for single-sided deafness. Post-implantation complications include local skin reactions and infections, skin hypertrophy over the abutment and failed osseointegration. There is presently a lack of information in the medical literature concerning the outcome and rate of complications in patients who simultaneously have BAHA implantation and temporal bone irradiation.

Objective: To compare the complications rate in BAHA patients with or without irradiation.

Study Design: Case series with retrospective chart review.

Setting: Tertiary university center with a referral otology and neurotology practice.

Methods: Individuals who underwent BAHA implantation between January 1, 2005 and July 15, 2013 were identified. Demographic data, surgical indications, history of primary oncologic surgery, length of follow-up after BAHA implantation, history and dosage of radiation, postoperative complications and chronologic relationship between primary oncologic surgery, BAHA implantation and irradiation were recorded. Soft tissue complications were graded according to a modification of Holgers classification.

Results: Twenty-eight patients underwent BAHA implantation alone, and 26 patients had a history of both BAHA surgery and radiation to the temporal bone. Of these 26 patients, 13 had undergone BAHA implantation at the time of the primary oncologic resection, 11 after the primary oncologic resection and 2 had a BAHA without any oncologic surgery. Patients' characteristics were similar between those having received radiotherapy and the control group, except there was a higher proportion of irradiated patients among males (59%) than females (32%), but not significantly so (p = 0.06). Overall, compared with the control group, higher proportions of patients who underwent both BAHA implantation and irradiation had some complication (34.6% versus 21.4%) as well as major complications (15.4% versus 3.6%) although these differences were not statistically significant. The major complications included soft tissue reactions requiring additional surgical excision (2/26), implant extrusion (2/26) and bone exposure around the implant (2/26).

Of all the complications that occurred in irradiated patients, most were found in those patients who had BAHA implantation delayed after the primary oncologic resection (8/11 versus 3/13, p = 0.04). Only one major complication was found in patients having the BAHA implanted at the time of the primary oncologic surgery, and no major complications were found in patients who had undergone BAHA implantation before receiving radiation.

Conclusion: BAHA implantation is an important measure to rehabilitate hearing after oncologic surgery. The rate and severity of complications can be minimized by implanting the device before irradiating the patient, ideally at the time of the primary oncologic surgery.