Relations between Scalar Shift and Insertion Depth in Human Cochlear Implantation

Introduction:

The intracochlear position of an electrode array may influence the outcome after cochlear implantation. Depending on the design, electrode arrays can be traumatic leading to penetration of the basilar membrane and shift of the electrode array into the scala vestibuli.

Methods:

Postoperative cone beam-computed tomography (CB-CT) scans were used for the identification of scalar shift in patients treated with two different electrode designs, a mid-scala and a perimodiolar electrode array developed by one manufacturer.

Results:

Scalar shift occurred 26.7% of the patients implanted with a perimodiolar electrode array and in 6.7% of the patients implanted mid-scala electrode array. The mean insertion depth in the patients experiencing scalar shift after implantation of a mid-scala electrode was much deeper (21.59 ± 0.34 mm) when compared to the mean insertion depth of the patients with scalar shift after implantation with a perimodiolar electrode array (17.85 ± 2.19 mm). There was no significant correlation between the cochlear length and the occurrence of a scalar shift.

Conclusion:

Based on the presented data, patients implanted with a perimodiolar electrode array are at a higher risk to develop cochlear trauma as indicated by a scalar shift.

Dr. Athanasia Warnecke

MHH HNO-Klinik,

Carl-Neuberg-Str. 1, 30625

Hannover

Email: [e-mail]

Publication History

Publication Date:
23 April 2019 (online)