Determination of contact-specific insertion angles using planning software for cochlear implantation.

Objective Tthe cochlea structure can vary between subjects. In order to take this great anatomical variability into account, the anatomy of a specific cochlea can be identified with the help of clinical digital volume tomography (DVT) and the electrode array that optimally supplies the respective patient can be selected. The OTOPLAN surgical planning platform enables to approximate the dimensions of the cochlea within imaging data by measuring the basal cochlear diameters, commonly referred to as parameters A and B. It also enables the specific prediction of the insertion angle for CI electrode arrays. This study was conducted to evaluate the precision of these prevision and compare them to the measurement of the cochlear length of the lateral wall by multiplanar reconstruction (MPR).

Methods Using the planning software, preoperative DVT scans of MED-EL cochlear implant patients were evaluated. This evaluation included measurements of the respective values ??of A and B to approximate the cochlea length as well as the prediction of the contact-specific insertion angle of the implanted electrode array and the comparison of angles with MPR. These predictions were made using both the primary approximation method implemented (based on an equation proposed by Escudé) and a novel, recently proposed approach (called ECA). All prevision were then compared to the true insertion angles (measured with MPR) derived from post-OP DVT images of the identic patient.

Results: The novel ECA approach resulted in fewer estimation errors than the algorithm based on the Escudé formula.

Discussion this evaluation with a preoperative planning software turned out to be simple, fast and clinical feasible.

Poster-PDF A-1567.pdf

Publication History

Article published online:
13 May 2021