Positive ECochG track patterns correlate with better hearing preservation after cochlear implantation

IntroductionElectrocochleography (ECochG) has emerged as a valuable intra-operative monitoring tool in cochlear implantation, particularly for preserving residual hearing. This study evaluates the correlation between intra-operative ECochG responses and post-operative hearing outcomes in cochlear implant recipients.Materials and methodsA cohort of 23 adult subjects with residual acoustic hearing in the low frequencies undergoing cochlear implantation were included. All subjects received Advanced Bionics' HiRes Ultra 3D implants and HiFocus SlimJ electrode arrays, with ECochG monitored during surgery via the AIM system. Intra-operative ECochG responses were categorized into positive, negative, and flat track patterns. Post-operative hearing outcomes were assessed at 1, 3, 6, and 12 months, focusing on hearing preservation.ResultsIn 70% of participants, recordable ECochG responses were obtained, with positive track patterns correlating with significantly lower mean hearing loss (17.1 dB) compared to negative (27.5 dB) and flat patterns (30.7 dB). At the 12-month post-operative mark, 83% of all participants retained complete or partial hearing preservation, with 100% complete or partial preservation in subjects exhibiting positive track patterns.DiscussionThis study highlights the association between intra-operative ECochG responses and post-operative acoustic hearing outcomes, indicating its potential as a monitoring tool during cochlear implantation. While ECochG provides real-time insights into cochlear function, this observational study did not evaluate whether acting on ECochG feedback improves outcomes. Therefore, these findings should be interpreted as correlational rather than interventional. Future research should include larger cohorts and investigate whether integrating ECochG-guided strategies into surgical protocols can enhance hearing preservation and long-term outcomes.