ECochG and fluoroscopy based individualized cochlear implantation

Introduction 

Intraoperative measurements such as evoked compound action potential (ECAP) and fluoroscopy are important tools to provide the surgeon with feedback about the condition of the cochlear health and the position of the electrode array during or after the insertion, in order to provide the patient with optimized and personalized implantation.

Methods 

The surgical setup was optimized by combining fluoroscopy with a suite of intraoperative electrophysiological measurements, including ECochG to allow the surgeon to monitor the response of the inner ear with reference to fluoroscopic assessment of electrode position during insertion.

This procedure was applied to five adult CI patients. Both the monitored ECochG signal and the fluoroscopy images were displayed to the surgeon simultaneously through a digital microscope. Insertion was paused at maximal insertion depths to perform electrophysiological measurements and then slightly pulled back to move electrode array near to modiolus.

Results 

Results show that ECAP thresholds become lower by 6 +- 7 CL (average and SD over all electrodes in the array) with positioning the electrode from a lateral position (average wrapping factor 0.71 +- 0.03 SD) close to the modiolus (average wrapping factor 0,65 +- 0,06 SD) The improvement of ECAP thresholds correlated with the distance decrease to the modiolus for individual electrode contacts and was most prominent for medial electrode contacts.

Conclusion 

By combining fluoroscopy and intraoperative measurements new insights can be gained between electrode position and electrophysiological status of the cochlea. This enables the surgeon to perform a personalized implantation.

Cochlear Ltd.

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Artikel online veröffentlicht:
24. Mai 2022