Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center.
Department of Mechanical Engineering.
Otol Neurotol. 2023 Apr 1;44(4):324-330. doi: 10.1097/MAO.0000000000003812. Epub 2023 Jan 18.
This study evaluated the utility of the pull-back technique in improving perimodiolar positioning of a precurved cochlear implant (CI) electrode array (EA) with simultaneous insertion force profile measurement and direct observation of dynamic EA behavior.
Precurved EAs with perimodiolar positioning have improved outcomes compared with straight EAs because of lowered charge requirements for stimulation and decreased spread of excitation. The safety and efficacy of the pull-back technique in further improving perimodiolar positioning and its associated force profile have not been adequately demonstrated.
The bone overlying the scala vestibuli was removed in 15 fresh cadaveric temporal bones, leaving the scala tympani unviolated. Robotic insertions of EAs were performed with simultaneous force measurement and video recording. Force profiles were obtained during standard insertion, overinsertion, and pull-back. Postinsertion CT scans were obtained during each of the three conditions, enabling automatic segmentation and calculation of angular insertion depth, mean perimodiolar distance ( Mavg ), and cochlear duct length.
Overinsertion did not result in significantly higher peak forces than standard insertion (mean [SD], 0.18 [0.06] and 0.14 [0.08] N; p = 0.18). Six temporal bones (40%) demonstrated visibly improved perimodiolar positioning after the protocol, whereas none worsened. Mavg significantly improved after the pull-back technique compared with standard insertion (mean [SD], 0.34 [0.07] and 0.41 [0.10] mm; p < 0.01).
The pull-back technique was not associated with significantly higher insertional forces compared with standard insertion. This technique was associated with significant improvement in perimodiolar positioning, both visually and quantitatively, independent of cochlear size.
本研究通过同时测量回拉过程中的插入力曲线并直接观察动态 EA 行为，评估了回拉技术在改善预弯耳蜗植入电极（CI）阵列（EA）的中周位置方面的效用。
与直形 EA 相比，预弯 EA 具有更好的中周位置，因为其刺激所需的电荷减少，并且兴奋扩散减少。但是，回拉技术在进一步改善中周位置及其相关力曲线方面的安全性和有效性尚未得到充分证明。
在 15 个新鲜的尸体颞骨中，去除覆盖前庭阶的骨，使鼓阶不受影响。使用机器人进行 EA 插入，并同时进行力测量和视频记录。在标准插入、过插入和回拉过程中获得力曲线。在这三种情况下，都在插入后进行 CT 扫描，以便自动分割和计算角度插入深度、平均中周距离（Mavg）和耳蜗管长度。
过插入并没有导致峰值力显著高于标准插入（平均[标准差]，0.18[0.06]和 0.14[0.08]N；p=0.18）。在该方案后，有 6 个颞骨（40%）的中周位置明显改善，而没有恶化的情况。与标准插入相比，回拉技术后 Mavg 显著改善（平均[标准差]，0.34[0.07]和 0.41[0.10]mm；p<0.01）。
与标准插入相比，回拉技术不会导致明显更高的插入力。该技术在中周位置方面有明显改善，无论是从视觉上还是从定量上，而且与耳蜗大小无关。
