Carina® and Esteem®: A Systematic Review of Fully Implantable Hearing Devices
OBJECTIVES (1) To assess outcomes of the Envoy Esteem Totally Implantable Hearing System as measured by hearing results compared with preimplant baseline unaided (BLU) and best-fit aided conditions (BLA) and (2) to determine safety of the device. STUDY DESIGN Prospective, nonrandomized, multicenter, subject-as-own-control, US Food and Drug Administration (FDA) trial. SETTING Private practice and hospital-based. SUBJECTS AND METHODS Between January 2008 and August 2009, an FDA trial was performed at 3 sites. Fifty-seven subjects with bilateral, mild to severe sensorineural hearing loss, with discrimination greater than 40%, were implanted. Implanted components were (1) a sound processor and (2) 2 piezoelectric transducers (a sensor and a driver). A sound processor was implanted in the temporal bone. Transducers were coupled to the ossicles. Devices were activated 2 months postimplant. Hearing results were compared with ipsilateral BLU and BLA. RESULTS Speech reception thresholds (SRTs) improved from BLA of 41.2 dB to 29.4 dB with the Esteem (P ≤ .001). Word recognition score (WRS) at 50 dB hearing level (HL) improved from BLA of 46.3% to 68.9% with the Esteem. Pure tone averages improved by 27 ± 1 dB (confidence interval, 30-25). There were no changes in bone conduction. QuickSIN results showed no change. There were 6 serious adverse device effects: 2 wound infections (1 resolved medically, 1 required explantation), 1 delayed facial paralysis that resolved with medication, and 3 revisions due to limited benefit. CONCLUSION Phase 2 results at 12 months post implant demonstrated that (1) hearing results with the device are statistically superior to baseline best-fit hearing aids for SRT and WRS and (2) the device is safe.