Design of electrode array and insertion technique are important for hearing preservation

Objective The preservation of cochlear anatomy is paramount for stable results after cochlear implantation. Neural structures depend on it as well as the implementation of future technologies. Conservation of residual hearing is a useful indicator.

Methods 155 patients with measurable residual hearing in at least 5 frequencies have been included in this retrospective study. In contrast to other research, the usability in the context of electroacoustic stimulation was not required. Loss of residual hearing was defined as the loss of detectability in at least 3 frequencies. Kaplan-Meier was used for the comparison of 4 electrode arrays.

Results Loss of residual hearing was detectable in 25 % , insertion via round window approach yielded better results (p=0.02). 75 %  conservation could be seen for AB Midscala (N=20) without a significant difference in insertion strategy. For MedEl Flex 28 (N=39), hearing could be conserved in 65 % , without distinction for round window vs. cochleostomy. CI422/CI522 by Cochlear (N=60) yielded 85 %  with significantly better results for round window insertion. Contour Advance (N=25) showed conservation in 60 % , using cochleostomy only.

Conclusion Slim, relatively short electrode arrays seem to increase the chance for hearing preservation as well as insertion via round window. Geometry and overall design of the electrode array as well as surgical approach are important for the conservation of cochlear anatomy.

Poster-PDF A-1657.pdf

Publication History

Article published online:
13 May 2021