Long-term outcome of round window vibrant soundbridge implantation in extensive ossicular chain defects

Objective. To evaluate retrospectively the long-term safety and efficacy of the first 50 patients, all suffering from severe ossicular chain defects and with moderate to severe mixed hearing loss, who received the Vibrant SoundBridge with the floating mass transducer located on the round window membrane. To evaluate differences in outcome versus etiology and age of the patient population. Study Design. Case series with planned data collection. Setting. Tertiary referral medical center. Subjects and Methods. Patients eligible for implantation of the floating mass transducer on the round window membrane ranged in age from 2 months to 74 years with a moderate to severe conductive or mixed hearing loss from different etiologies. For each adult patient, preoperative versus postoperative bone and air conduction thresholds, air-bone gaps, and speech understanding scores were evaluated at 24-month follow-up. At 60-month follow-up, data were available from 33 patients. Preoperative and postoperative freefield auditory brainstem responses were studied in infants and children. Intraoperative and short- and long-term postoperative complications are presented. Results. There were significant improvements in speech perception and pure-tone audiometry in adults and auditory brainstem response thresholds in infants immediately after surgery and at follow-up examinations (12 to 71 months). No significant complications or device extrusions were observed in the present series. Conclusions. Infants, children, and adults with moderate to severe conductive or mixed hearing loss obtained substantial benefit from implantation of the floating mass transducer on the round window membrane regardless of the etiology of hearing loss and previous surgery.