Radiologic evaluation of multichannel intracochlear implant insertion depth.

TLDR

Postoperative plain‑film x‑rays are required for all multichannel cochlear implant patients to confirm intracochlear position, detect electrode kinking, and provide a reference for postoperative slippage, and precise documentation of insertion depths is necessary for comparing speech‑recognition results and informing future speech‑processing strategies. The study aims to devise a method to more accurately document insertion depths of the electrode array and the location of individual electrodes in multichannel cochlear implant patients. The method uses a modified Stenver’s view to measure insertion depths and electrode positions in 50 patients. Surgical estimates of insertion depth vary greatly compared with x‑ray measurements, and preliminary evidence shows a strong correlation between x‑ray‑determined depth and open‑set speech discrimination.

Abstract

Postoperative plain film x-rays are necessary in all multichannel cochlear implant patients to confirm intracochlear position, detect possible electrode kinking, and provide a reference if postoperative slippage occurs. In addition, precise documentation of multichannel intracochlear electrode insertion depths is necessary for comparison of speech recognition results among patients and may be of use for future speech processing strategies. In the present study, a method has been devised, using a modified Stenver's view, to more accurately document insertion depths of the electrode array and location of individual electrodes on 50 multichannel cochlear implant patients. Surgical estimates of insertion depth are shown to have great variability in regard to distance along the basilar membrane when compared with x-ray documentation. Additionally, there is preliminary evidence that insertion depth, as determined by x-ray studies, has a strong correlation with open-set speech discrimination.