Comparison of electrode position between round window and cochleostomy inserting approaches among young children: a cone-beam computed tomography study

Abstract

Background: As the two most commonly used approaches for cochlear implants (CIs), the round-window insertion (RWI) and cochleostomy are still controversial about which approach is optimal. The lack of visual observation methods makes it difficult to compare the electrode position between them.

Objectives: To evaluate and compare the electrode position between RWI and cochleostomy approaches for CI among young children.

Materials and methods: Twenty-four patients (16 male, 8 female) accepting CI and temporal cone-beam computed tomography (CBCT) scan post-operation in our hospital from January 2016 to July 2017 were analyzed retrospectively. Operative notes and images were used to identify the surgical technique. Mainly depending on the round-window exposure, 15 cochleae were performed with RWI and 11 performed with cochleostomy.

Results: Mean age, 2.4 (range 0.8–7) years. The CBCT images showed that all the electrode arrays were located in scala tympani. There were no significantly statistical differences in the distance between electrode contacts and modiolus (EMI), intracochlear insertion length and the angle of electrode arrays at the insertion site of the cochlea.

Conclusions and significance: Both approaches could insert electrodes into scala tympani satisfactorily. As electrodes and cochlear structures could be clearly visualized, CBCT can be applied to assess the electrode position reliably.

Chinese abstract

背景：人工耳蜗植入（CIs）的两种最常用的方法, 圆窗插入（RWI）和耳蜗造口术, 仍然处于争议中：究竟哪种方法是最佳的。目视观察方法的缺​​乏使得难以比较它们之间的电极位置。

目的：评估和比较儿童的圆窗插入法和耳蜗造口术之间的电极位置。

材料与方法：回顾性分析了2016年1月至2017年7月在我院接受CI和术后颞叶锥束计算机断层扫描（CBCT）检查的24例患者（男性16例, 女性8例）。使用手术笔记和图像来识别手术方法。主要依据圆窗暴露, 15个耳蜗用RWI植入, 11个用耳蜗造口术植入。

结果：平均年龄为2.4（0.8-7岁）。 CBCT图像显示所有电极阵列位于鼓阶。电极触点与蜗轴（EMI）之间的距离、耳蜗内插入长度以及耳蜗插入位置处的电极阵列的角度没有显著的统计学差异。

结论和意义：两种方法都可以令人满意地将电极插入鼓阶。由于电极和人工耳蜗结构可以清晰地显示出来, 锥束计算机断层扫描可以用于可靠地测定电极位置。

Keywords:

• Cochlear implant
• round-window insertion
• cochleostomy
• cone-beam computed tomography
• electrode
• cochlea
• cochlear anatomy

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Natural Science Foundation of China [grant number 81570924], and Key research and development plan of Shandong Province [grant number 2016GSF201089].