Transimpedance Matrix (TIM) Measurement for the Detection of Intraoperative Electrode Tip Foldover Using the Slim Modiolar Electrode: A Proof of Concept Study.

OBJECTIVES The aim of this study is to report on our preliminary experience with Transimpedance Matrix (TIM)-measurement for the detection of cochlear implant electrode tip foldovers compared with intraoperative imaging in patients implanted with the slim modiolar electrode (SME). STUDY DESIGN Proof of concept study. SETTING Tertiary university referral center. PATIENTS Twenty five ears (in 22 patients) implanted consecutively with the SME. INTERVENTION(S) Following cochlear implantation, intraoperative TIM-measurement and fluoroscopy were performed. One week postoperatively, the electrode position was evaluated using Computed Tomography (CT)-imaging. MAIN OUTCOME MEASURES Electrode array tip foldover. RESULTS Electrode array tip foldover occurred in three of the 25 cochlear implantations performed (12%). In each case, the foldover was detected by both TIM and fluoroscopy, leading to reposition and correct intracochlear placement of the array. CONCLUSIONS TIM-measurement is a promising method for the intraoperative detection of an electrode array tip foldover. The TIM-tool with intuitive heatmap display is easy to use, fast, and readily available to clinics using TIM-software in the operating theatre.