2025/11/19 by Schmidt, Florian Herrmann, Zhang, Lichun, Ehrt, Karsten +2
Neuroscience · Health Professions · #Hearing Loss and Rehabilitation #Hearing, Cochlea, Tinnitus, Genetics #Medical Practices and Rehabilitation
paper · doi:10.3205/zaud000075
Introduction: The insertion depth of cochlear implants (CIs) plays a crucial role in auditory perception, as the final position of the electrode array determines which frequency-specific neural structures are stimulated. The Slim Straight Electrode from Cochlear Ltd. enables surgeons to vary the insertion depth during implantation to best suit the individual anatomical and clinical needs of each patient. However, there are currently no clear intraoperative reference points to indicate when the desired insertion depth has been achieved. Transimpedance measurement is a fast, radiation-free electrophysiological technique that may offer a viable method for estimating insertion depth. Methods: Intraoperative transimpedance measurements were performed in 39 patients. Gradient fields were derived from the resulting transimpedance matrices (TIM), and the phases of these gradients were correlated with the insertion depths as determined postoperatively by radiological imaging. Results: A strong correlation (R=0.80) was observed between insertion depth and gradient phase. Notably, electrode pairs located in the apical-medial region had the greatest influence on determining insertion depth. Conclusion: Intraoperative transimpedance measurement is an effective method for assessing the insertion depth of cochlear implant electrodes. It offers valuable intraoperative guidance, particularly for electrode arrays with variable insertion depths, such as Cochlear’s Slim Straight electrode.