On the battery life of a totally implantable active middle ear device: a retrospective study in a single implanting center

Background: Totally-implantable active middle ear devices (AMED) rely on a non-rechargeable battery encased with the implantable sound processor that needs to be replaced with a minor surgical pro- cedure after its depletion. Objectives: This study aimed to investigate the most significant factors affecting the implant’s bat- tery life. Materials and Methods: The implanted subjects (29 patients) were divided into three groups; group A with 17 patients who underwent one battery change surgery; group B with ten patients who under- went two battery changes; and group C with two patients and three surgeries. The battery life was put in correlation with several variables, including daily use and the auditory threshold. Results: The battery life ranged from 26 to 67 months, with a mean of 48.93 ± 13.47. Pearson’s correl- ation coefficient revealed that the battery life was statistically correlated only with the mean post- implantation bone conduction thresholds (p-value <.0001). Conclusions: Although the non-rechargeable battery system of the AMED under study overcomes the drawbacks of daily charging, it needs to be surgically changed after its depletion. The different rates of battery life were shown to mainly depend on the post-implantation BC thresholds, which in some cases showed a deterioration concerning the pre-implanting values.