Cochlear Implant Revision Surgery: Risk Factors and Outcomes

<b>Introduction:</b> At the Department of Otolaryngology, USK1 PUM in Szczecin, 205 cochlear implant surgeries were performed between 2008 and 2023 in patients with bilateral profound sensorineural hearing loss. Reimplantation was necessary in 8 cases, 3 of which were primarily operated on outside our clinic. The re-implantation rate at the local centre is 2.4%.<b>Aim:</b> The aim of this study was to analyse the reasons for reimplantation and the surgical procedure at the Department of Otolaryngology in Szczecin. In addition, changes in electrophysiological parameters of electrode impedance, transimpedance measurement, and neural response telemetry (NRT) were assessed.<b>Materials and methods:</b> Electrophysiological tests (impedance and NRT) were measured before and after the reimplantation procedure, followed by statistical analysis of the changes in the values of the collected measurements.<b>Results:</b> Reasons for reimplantation comprised: tip fold-over n = 2, extrusion of the implant n = 2, recurrent mastoiditis n = 1, recurrent chronic otitis media with cholesteatoma n = 1, failure of the internal part of the device n = 2. Healing was normal in all patients. Analysis shows that reimplantation leads to a change in impedance. The variability between patients is very significant. In contrast, for NRT, all patients had a decrease in recorded values or no change, but the variation in effect between patients was not significant, allowing the general conclusion that reimplantation typically causes a decrease in NRT values.<b>Discussion:</b> Given the observed changes in NRT and impedance values in patients after reimplantation surgery, each patient should be treated as newly implanted during the activation of the cochlear implant speech processor.<b>Conclusions:</b> Surgical re-treatment was successful in all cases. Post-treatment follow-up has shown that reimplantation allows continued successful use of the cochlear implant system.