Electrode array design influences scalar position, dislocation rate and angle and postoperative speech perception

Objective The aim of this study is to examine scalar dislocation rate in straight and perimodiolar electrode arrays. Furthermore, to analyze the specific dislocation angle of electrode arrays depending on their design and to compare those to postoperative speech perception.

Methods We conducted a comparative analysis of patients (n=548) (2013 – 2018) inserted with a perimodiolar or straight electrode array (Cochlear™ (N=360): Contour Advance®, slim straight® and slim modiolar®, MED EL (n=188): Flex^Soft, Flex²⁴ and Flex²⁸ electrode array). Rotational tomography was used to determine electrode array position (scalar position, dislocation, angle of dislocation and insertion angle) and postoperative speech discrimination has been compared.

Results Perimodiolar electrode arrays showed significant shorter coverage than straight ones. The electrode array with the highest rate of scala vestibuli (SV) insertions was the Contour Advance; the highest dislocation rate showed the Flex^Soft (length: 31.5mm). The slim modiolar showed no dislocation. The angle of dislocation is electrode design specific. Perimodiolar electrode arrays dislocate between 170 and 190°, whereas straight ones dislocate between 360 and 390°. SV insertion takes significant influence on postoperative speech discrimination, whereas dislocation and insertion angle have no significant influence on postoperative speech perception.

Conclusion Electrode array position, dislocation rate and angle significantly depend on the electrode array design. SV insertion decreases the values for monosyllables in regular script and for sentence discrimination in parentheses of exact 10.6%. Scalar dislocation and the insertion angle itself have no significant influence on postoperative speech perception.

Poster-PDF A-1537.PDF

Publication History

Article published online:
10 June 2020