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The impact of electrode type on intraoperative and postoperative telemetry measures in cochlear implant using different surgical technique




Cochlear implantation (CI) is largely considered successful based on the device’s ability to reliably send electrical signals to the auditory nerve fibers. Telemetry (electrode impedance) is a bidirectional communication system. The telemetry system allows us to test the basic functions of a CI and to detect the electrical problems in each electrode.


The aims of this study were to monitor electrode telemetry at the intraoperative and initial-activation postoperative periods and to correlate the telemetry measures with the type of inserted electrode and surgical technique.

Patients and methods

A retrospective analysis of impedance data from 69 CI surgeries occurring at the Hearing and Speech Institute was conducted. Intraoperative and postoperative impedance values were available in 69 pediatric and adult patients during the first fitting 3 weeks to 1 month postoperatively. The data obtained in this study were divided into four groups depending on the type of implanted electrode and device used. In this research, four types of electrodes (Mid Scala, 1J, Flex 28, and Standard) and two surgical techniques (cochleostomy and round window) were used.


Findings showed that there is a statistically significant difference between intraoperative and postoperative mean average of telemetry measure for 1J and Flex 28 electrodes that increased postoperatively. There was no statistically significant difference between intraoperative and postoperative mean±SD of each of the two electrodes (Mid Scala, 1J, Flex 28, and Standard). Comparison between intraoperative and postoperative average of the four electrodes shows statistically significant difference in intraoperative average. The study also showed that there is no statistical difference between telemetry results when either cochleostomy or round-window approaches were used.


Findings of this research showed increase in postoperative impedance with all types of electrodes, which can be referred to the absence of electrical stimulation prior to initial activation of the device. There is statistically significant difference in intra-operative telemetry average between four types of used electrode.


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Correspondence to Soha Hamada MD.

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Hamada, S., Omara, A., Sefein, I.K. et al. The impact of electrode type on intraoperative and postoperative telemetry measures in cochlear implant using different surgical technique. Egypt J Otolaryngol 32, 264–270 (2016).

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  • cochlear implant
  • electrodes
  • telemetry