Department of Otolaryngology, Head and Neck Surgery, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany.
Institute of Diagnostic and Interventional Radiology, University Hospital, Frankfurt, Germany.
Eur Arch Otorhinolaryngol. 2021 Nov;278(11):4209-4216. doi: 10.1007/s00405-020-06504-8. Epub 2021 Jan 2.
For cochlear implants (CI) with removable magnets, a pressure bandage usually is recommended during MR imaging to avoid magnet dislocation. Nevertheless, this complication is regularly observed despite applying a pressure bandage. The aim of this study was to compare various bandaging techniques to avoid magnet displacement.
As an experimental model a force measuring stand was developed and validated, on which the process of magnet dislocation could be simulated on a cochlear implant. In a test series with six combinations of cohesive and elastic bandages with different counter pressure elements (CPE), the forces required to induce magnet dislocation against the resistance of a compression bandage was determined. In addition, the inter- and intraindividual variability of the compression bandages was measured for ten different users.
The cohesive bandage had the lowest average holding force of 10.70 N. The elastic bandage developed more than four times the retention force of the cohesive bandage (44.88 N, p < 0.01). By adding a CPE, these values could be increased highly significantly up to factor 3. The optimum combination in terms of fixation force against magnet dislocation was an elastic bandage plus a cylindrical CPE (76.60 N). The data showed a high interindividual variability.
Even though most CI manufacturers now offer 3T-conditional implants, a pressure bandage will have to be applied to thousands of patients with previous implant generations to prevent magnet dislocation. We examined for the first time force measurements to compare different bandaging techniques by detecting the holding force of the CI magnet. We were able to identify an optimized combination of a bandage and a CPE to immobilize the CI magnet. However, our data also demonstrated a significant scatter amongst different examiners. Although our data provide valuable data for potential clinical application, future development of the dressing technique is required for human use.
对于可移除磁铁的人工耳蜗（CI），磁共振成像（MRI）期间通常建议使用压力绷带以避免磁铁脱位。然而，尽管使用了压力绷带，这种并发症仍经常发生。本研究旨在比较各种绷带技术以避免磁铁移位。
作为实验模型，开发并验证了一个力测量台，可在人工耳蜗上模拟磁铁脱位的过程。在一项有六个组合的弹性和粘性绷带与不同抗压元件（CPE）的测试系列中，确定了在压缩绷带的阻力下引起磁铁脱位所需的力。此外，还测量了十个不同使用者的压缩绷带的个体内和个体间变异性。
粘性绷带的平均保持力最低，为 10.70 N。弹性绷带产生的保持力是粘性绷带的四倍多（44.88 N，p < 0.01）。通过添加 CPE，可以将这些值显著提高至 3 倍以上。在防止磁铁脱位的固定力方面，最佳组合是弹性绷带加圆柱形 CPE（76.60 N）。数据显示个体间存在高度的变异性。
尽管现在大多数 CI 制造商都提供 3T 条件的植入物，但为了防止磁铁脱位，数千名先前植入物的患者仍将需要使用压力绷带。我们首次通过检测 CI 磁铁的保持力来检查力测量，以比较不同的绷带技术。我们能够确定一种绷带和 CPE 的最佳组合来固定 CI 磁铁。然而，我们的数据也显示了不同检查者之间存在显著的差异。虽然我们的数据为潜在的临床应用提供了有价值的数据，但仍需要进一步开发敷料技术以供人类使用。
