Application of the Vibrant Soundbridge ^® to unilateral osseous atresia cases

Objectives/Hypothesis: Patients with highgrade atresia-microtia suffer from a combined malformation of the outer and middle ears, typically leading to a severe hearing impairment. Long-term results of middle ear reconstruction with tympanoplasty are often insufficient due to persistent air-bone gaps, and new techniques in hearing rehabilitation are required. The objective of this research is to evaluate the active middle ear implant, the Vibrant Soundbridge ^® (VSB), for hearing rehabilitation of patients with unilateral osseous aural atresia. Study Design: Prospective analysis of a consecutive cohort of seven atresia patients (mean age=15 years). Methods: During plastic auricular reconstruction of unilateral atresia-microtia cases, an access through the bony atresia plate was drilled. The floating mass transducer was coupled to the stapes (or remaining stapes suprastructure), ossicular chain, or round window, depending on the anatomic needs of the patient. Audiometric testing, including pure-tone thresholds, and speech testing in quiet and noise were performed. Results: The mean threshold with the VSB activated in the free field warble tone audiometry was 23.8 dB hearing level (HL). Mean functional gain was 45.5 dB HL. Mean aided free field speech discrimination in quiet was 64% at 50 dB, 99% at 65 dB, and 100% at 80 dB. Conclusions: By circumventing the malformed middle ear and directly stimulating the cochlea, the VSB provides a new rehabilitation option for atresia patients. We conclude that the procedure is safe and effective and can be implemented in combination with outer ear reconstruction.