Universitas Indonesia/Dr. Cipto Mangunkusumo Hospital, Faculty of Medicine, Department of Otorhinolaryngology Head and Neck Surgery (ORL-HNS), Jakarta, Indonesia.
Med J Malaysia. 2023 Sep;78(5):589-593.
Monitoring of impedance field telemetry is crucial to maintaining optimal function of cochlear implants. This study aims to investigate impedance changes in cochlear implant electrodes one year after switch on.
A retrospective repeated crosssectional study was conducted by recruiting patients with cochlear implants presenting to the Dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia between 2017 and 2021. Basal (b1, b2) and apical (a1, a2) electrodes, representing the outermost and innermost parts of the cochlear implant electrodes, were measured at switch on and at 1 year post-implantation.
A total of 123 patients, with a total of 123 cochlear implant samples, were included in the analysis. We found a substantial change in electrical impedance between switch on and follow-up periods, where the impedance levels of basal electrodes decreased (b1: mean difference (MD) -1.13 [95% confidence interval (CI): -1.71, -0.54], p<0.001; b2: MD -0.60 [95%CI: -1.17, -0.03], p=0.041) and those of apical electrodes increased (a1: MD 0.48 [95%CI: -0.28, 0.99], p=0.064; a2: MD 0.67 [95%CI: 0.12, 1.22], p=0.017). We also found that the choice of surgical approaches for implant insertion may affect the electrode impedance. Cochleostomy approach resulted in a higher impedance than round window in basal (b1) and apical (a2) electrodes both at switch on and follow-up (b1 at switch on and at follow-up: p=0.019 and p=0.004; a2 at follow-up: p=0.012). Extended round window approach also resulted in a higher impedance than round window in basal (b1) and apical (a2) electrodes at follow-up (p=0.013 and p=0.003, respectively).
Electrical impedance of cochlear implant electrodes may change over time, highlighting the importance of regular impedance assessments for cochlear implant users to ensure optimal device function. The round window approach resulted in better initial and long-term impedance levels compared to cochleostomy, and better long-term impedance levels than extended round window. Extended round window approach also gives better impedance level than cochleostomy. Further research should investigate the potential interplay between surgical approach and other factors that may impact impedance levels to confirm our findings.
监测阻抗场遥测对于维持耳蜗植入物的最佳功能至关重要。本研究旨在探讨植入后一年耳蜗植入电极的阻抗变化。
通过招募 2017 年至 2021 年期间在印度尼西亚雅加达的 Cipto Mangunkusumo 国家综合医院就诊的耳蜗植入患者，进行回顾性重复横断面研究。在开机时和植入后 1 年测量最外层的基底（b1、b2）和最内层的顶点（a1、a2）电极的阻抗。
共纳入 123 名患者（共 123 例耳蜗植入样本）进行分析。我们发现开机和随访期间电极的电阻抗有显著变化，基底电极的阻抗水平降低（b1：平均差值（MD）-1.13[95%置信区间（CI）：-1.71，-0.54]，p<0.001；b2：MD-0.60[95%CI：-1.17，-0.03]，p=0.041），顶点电极的阻抗水平升高（a1：MD 0.48[95%CI：-0.28，0.99]，p=0.064；a2：MD 0.67[95%CI：0.12，1.22]，p=0.017）。我们还发现，植入物插入的手术方法选择可能会影响电极的阻抗。与圆窗相比，耳蜗造瘘术在开机时和随访时的基底（b1）和顶点（a2）电极的阻抗均更高（b1 在开机和随访时：p=0.019 和 p=0.004；a2 在随访时：p=0.012）。扩展圆窗入路也比圆窗在基底（b1）和顶点（a2）电极的阻抗更高（分别在随访时：p=0.013 和 p=0.003）。
耳蜗植入电极的电阻抗可能会随时间发生变化，这强调了定期进行阻抗评估对于确保耳蜗植入用户的设备功能优化的重要性。与耳蜗造瘘术相比，圆窗入路可获得更好的初始和长期阻抗水平，与扩展圆窗相比，圆窗入路可获得更好的长期阻抗水平。扩展圆窗入路也比耳蜗造瘘术提供更好的阻抗水平。进一步的研究应调查手术方法和其他可能影响阻抗水平的因素之间的潜在相互作用，以证实我们的发现。
