Results and complications of the Baha system (bone-anchored hearing aid).

The aim of this work is to reexamine our experience with the treatment of conductive and mixed hearing loss using the Baha system. The system was implanted in 47 patients (16 adults and 31 children under the age of 14), bilaterally in two cases. The causes of hypoacusis were bilateral congenital aural atresia (31 patients), bilateral chronic otitis media or outcomes of middle-ear surgery (Gillett et al. in J laryngol Otol 120:537-542, 2006), and otosclerosis (Pazzaglia et al. in Acta Orthop Scand 54:574-579, 1983). The following parameters were assessed: mean preoperative air- and bone-conduction thresholds for the frequencies of 500, 1,000, 2,000 and 4,000 Hz; mean postoperative threshold with the Baha; hearing improvement calculated by subtracting the postoperative threshold with the Baha from the preoperative threshold for air conduction in the better ear; speech audiometry test; improvement in the quality of life, calculated using the Glasgow Benefit Inventory for the adult patients and the Glasgow Children's Benefit Inventory for paediatric patients; frequency and type of surgical complications. Follow-up ranged from 6 to 38 months. The audiological results were satisfactory, with air-bone gap closure in 85.1% of cases. In terms of quality of life, assessment using the Glasgow Benefit Inventory showed a clear-cut improvement in health for all the 45 patients that answered to the questionnaires in our study. Out of the 49 operations that were performed, complications were reported in 3 cases (6.1%): 2 cases of skin regrowth around the titanium screw and one in which the abutment was not osseointegrated. The data from this study show that the Baha system offers a high percentage of success, which can significantly improve the patient's quality of life, and a low rate of complications.