Faktoren, die das Ergebnis der Cochlea-Implantat-Versorgung beeinflussen: Besteht ein Zusammenhang zwischen Elektroden-Einführwinkel/Frequenzversatz und Einsilberverstehen?

Objective: The objective of this study is to examine the efficacy of cochlear implants (CIs) in restoring hearing in individuals with hearing impairment. Cochlear implants (CI) are medical devices that are used to restore the hearing of patients who are deaf or hard of hearing. Nevertheless, achieving optimal hearing outcomes remains challenging. The existing literature has addressed the potential factors that may influence these outcomes; however, these factors have not been fully elucidated. The present study aims to address this knowledge gap by analyzing the effects of Angular Insertion Depth (AID) and Frequency Mismatch (FMM) on Speech Understanding (SU) in a large cohort of patients with five different electrode arrays. Methodology: N=101 implant cases were included in the study. Electrode insertions of the following implants were examined: N=43 Synchrony implants (MED-EL, Innsbruck, Austria) with FLEX26 and FLEX28 electrodes, and N=58 Nucleus implants (COCHLEAR, Macquarie, Australia) with PRECURVED, STRAIGHT and CONTOUR SLIM electrodes. Postoperative CT data sets were analyzed using the Otoplan V3.0 analysis program (CASCINATION, Bern, Switzerland) to determine the electrode positions. The tonotopic frequency allocation and the FMM were then evaluated. Postoperative speech comprehension was determined for all subjects using the Freiburg monosyllable test in quiet (FMT) after an average of 12.2±5.9 months. Results: The mean CDL (cochlear duct length) was 35.8±3.1 mm (N=101). The AID values showed the following results: PRECURVED 329.4±39.7° (N=34), STRAIGHT 344.2±34.4° (N=9), CONTOUR SLIM 394.3±37.3° (N=10), FLEX26 496.3±45.0° (N=10) and FLEX28 554.8±49.3° (N=33). The largest FMM was found at the most apical electrode. Independent of the manufacturer, the cohort with AID 400–450° (N=9) achieved the best speech discrimination with 80%. Conclusion: The use of Otoplan V3.0 in clinical practice for the determination of CDL and AID was found to be practicable. No significant correlation was found between FMM and FMT, nor between AID and FMT. The results suggest that FMM may not be as crucial for speech comprehension of monosyllabic test words as previously assumed.