Phase 1 clinical trial results of the envoy system: A totally implantable middle ear device for sensorineural hearing loss

OBJECTIVES. This report will present the results of the USA Phase I clinical trials for the Envoy System (St. Croix Medical): A totally implantable middle ear hearing system for sensorineural loss. STUDY DESIGN: A prospective, single-subject, repeated-measures, multicenter study was performed to evaluate safety and functionality of the Envoy System. Data collected included Abbreviated Profile of Hearing Aid Benefit, bone conduction threshold, speech reception threshold, functional gain, word recognition, and adverse events. Testing was performed unaided, with the patient's best-fit hearing aid, and post device activation at 2 (trial endpoint) and 4 months. RESULTS. Five of 7 patients at the 2-month postactivation period had working systems. All 5 patients perceived benefit increases with the Envoy System over their best-fit hearing aid, including communication in high background noise levels. Word recognition was improved over hearing aids. Functional gain and speech reception thresholds were similar for the Envoy device and hearing aids. CONCLUSIONS., The feasibility trial has shown the Envoy device, a totally implantable middle ear de-vice, can safely sense and drive the ossicular chain.