A systematic review of electrode array scalar dislocation after cochlear implant surgery
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Published on: August 4, 2023
Huajie Bu1, Eva Maria Fritz1, Patrick F Connolly1
1MED-EL Elektromedizinische Geräte GmbH, Innsbruck, Austria.
Purpose:
The aim of this systematic review was to determine the rates of scalar dislocation (SD) after cochlear implant surgery with two types of electrode arrays (lateral wall, LW, and pre-formed, PF) from three manufacturers.
Methods:
Literature databases were systematically searched for relevant articles covering three time periods between August 2014 and December 2023. Retrieved articles were evaluated for inclusion in further analysis. We performed a quantitative synthesis to estimate the overall rates of SD with each array type and manufacturer, and to test if these differences were significant.
Results:
66 publications covering 4,729 implantations were used for the systematic review. These implantations included 1,782 LW arrays and 2,737 PF arrays. The breakdown according to manufacturer was 903 arrays from MED-EL, 2,527 from Manufacturer A, 850 from Manufacturer B, and 449 where the manufacturer was unspecified. SD occurred in 923 cases overall (19.5%). The SD rates by array type were 8.1% for LW arrays and 25.0% for PF arrays. The SD rates by manufacturer were 6.4% for MED-EL arrays, 23.2% for Manufacturer A arrays, and 21.3% for Manufacturer B arrays. The SD rate was significantly lower for MED-EL LW arrays compared to Manufacturer A LW arrays (p = 0.001). Within manufacturers, the SD rate was significantly lower for LW arrays compared to PF arrays for both Manufacturer A and Manufacturer B devices (both p < 0.001).
Conclusion:
Rates of SD vary by array type and manufacturer. LW arrays had the lowest rate. By manufacturer, MED-EL arrays had the lowest rate.
