Data_Sheet_1_Vestibular Organ and Cochlear Implantation–A Synchrotron and Micro-CT Study.docx

Background: Reports vary on the incidence of vestibular dysfunction and dizziness in patients following cochlear implantation (CI). Disequilibrium may be caused by surgery at the cochlear base, leading to functional disturbances of the vestibular receptors and endolymphatic duct system (EDS) which are located nearby. Here, we analyzed the three-dimensional (3D) anatomy of this region, aiming to optimize surgical approaches to limit damage to the vestibular organ.
Material and Methods: A total of 22 fresh-frozen human temporal bones underwent synchrotron radiation phase-contrast imaging (SR-PCI). One temporal bone underwent micro-computed tomography (micro-CT) after fixation and staining with Lugol's iodine solution (I2KI) to increase tissue contrast. We used volume-rendering software to create 3D reconstructions and tissue segmentation that allowed precise assessment of anatomical relationships and topography. Macerated human ears belonging to the Uppsala collection were also used. Drilling and insertion of CI electrodes was performed with metric analyses of different trajectories.
Results and Conclusions: SR-PCI and micro-CT imaging demonstrated the complex 3D anatomy of the basal region of the human cochlea, vestibular apparatus, and EDS. Drilling of a cochleostomy may disturb vestibular organ function by injuring the endolymphatic space and disrupting fluid barriers. The saccule is at particular risk due to its proximity to the surgical area and may explain immediate and long-term post-operative vertigo. Round window insertion may be less traumatic to the inner ear, however it may affect the vestibular receptors.

背景：目前针对人工耳蜗植入（cochlear implantation，CI）术后患者的前庭功能障碍与眩晕发病率，各研究报道结果不一。手术操作累及耳蜗底周时，可能引发平衡失调，进而导致毗邻的前庭感受器与内淋巴导管系统（endolymphatic duct system，EDS）出现功能紊乱。本研究对该区域的三维（three-dimensional，3D）解剖结构开展分析，旨在优化手术入路以降低对前庭器官的损伤。
材料与方法：共纳入22例经低温冷冻保存的人类颞骨标本，均接受同步辐射相位衬度成像（synchrotron radiation phase-contrast imaging，SR-PCI）检测。其中1例颞骨标本经卢戈碘液（Lugol's iodine solution，I2KI）固定染色以提升组织对比度后，完成显微计算机断层扫描（micro-computed tomography，micro-CT）成像。本研究采用容积重建软件进行三维重建与组织分割，可精准评估解剖关系与局部形貌。此外还使用了乌普萨拉馆藏的脱钙人类耳部标本。通过对不同手术路径开展量化分析，完成了人工耳蜗电极的钻孔植入操作。
结果与结论：同步辐射相位衬度成像与显微计算机断层扫描清晰呈现了人类耳蜗底周、前庭装置与内淋巴导管系统复杂的三维解剖结构。耳蜗造孔术的钻孔操作可能损伤内淋巴间隙、破坏流体屏障，进而干扰前庭器官功能。球囊因紧邻手术区域而面临更高的损伤风险，这或可解释术后即刻与长期眩晕的发生机制。经圆窗植入术对中耳的创伤性相对更低，但仍可能对前庭感受器造成影响。