Comparison between new and old generation RetroX® auditory implants

Comparison between new and old generation RetroX® auditory implants. Objective: To compare post aural soft tissues tolerance of the old and new titanium RetroX® (Auric GmbH, Rheine, Germany) tube, and to compare the hearing improvements between the old (DSP-pro®) and the new (Concertino®) hearing aid units of the RetroX.

Methodology: Retrospective case review of 46 patients with high-frequency sensorineural hearing loss, fitted with DSP-pro or Concertino, and who received 51 implantations (with the old or new generation titanium tube) in a tertiary referral center at a university hospital. The RetroX consists of an electronic unit situated in the postaural sulcus connected to a titanium tube implanted under the auricle between the sulcus and the external auditory meatus. Implanting requires minor surgery (10 minutes under local anaesthesia).

Three months after their implantation, patients were asked to fill out a questionnaire to evaluate acoustic feedback annoyance and to undergo 3 audiometric tests: pure-tone audiometry in silence, speech audiometry in silence, and speech audiometry in noise.

Results: The new tube is more reliable (12 explantations from patients who received 26 older tubes compared with 1 explantation in 25 who received new tubes) even if the size must be adjusted more often (2/26 for the old model and 5/25 for the new one). Concertino allows a higher amplification before feedback appears, which improves hearing gain.

Conclusions: The new RetroX is better tolerated than the older one, and improves hearing ability.