颞骨高分辨率CT的圆窗解剖学特征及在人工耳蜗植入术中的意义

Anatomic characteristics of round window in temporal bone high resolution CT and implications in cochlear implantation

目的基于颞骨高分辨率CT(HRCT),建立以圆窗为核心的解剖学特征测量方法,以预测人工耳蜗植入(CI)术中圆窗暴露的难易程度。方法对60例在北京大学第三医院行CI手术患者的术前颞骨HRCT及术中圆窗暴露情况进行回顾性分析,测量CT上以圆窗为核心的8个解剖学特征参数,分别将其与CI术中圆窗暴露程度进行比较,并利用SPSS 25.0统计学软件进行处理。结果耳蜗底转线-中矢状线、耳蜗底转线-外耳道线、外耳道线-中矢状线之间的角度,以及面神经与外耳道线的垂直距离对圆窗暴露难易程度的影响无统计学意义。圆窗-面神经连接线和经面神经的冠状位线之间的角度、圆窗与此线的垂直距离、经面神经且平行于外耳道的延长线与圆窗的位置关系,以及耳蜗底转延长线与面神经的位置关系对圆窗暴露难易程度的影响均具有统计学意义。结论术前颞骨HRCT上圆窗-面神经连接线和经面神经的冠状位线之间的角度越小,圆窗与此线的垂直距离越近,CI术中圆窗暴露越困难;通过经面神经且平行于外耳道的延长线与圆窗的位置关系以及耳蜗底转延长线与面神经的位置关系可以预测CI术中圆窗暴露的难度。

Objective To establish a method based on high resolution X-ray computed tomography(HRCT)of the temporal bone for the measurement of anatomical features with round window(RW)as the core,in order to predict the RW accessibility to cochlear implantation(CI).Methods The preoperative temporal bone HRCT and intraoperative RW accessibility of 60 patients who undergone CI surgery in the Peking University Third Hospital were retrospectively analyzed.Eight anatomical characteristic parameters with RW as the core in CT were measured and compared with the RW accessibility of CI respectively.SPSS 25.0 software was used for statistical analysis.Results There was no statistical significance in the influence of the angle between the cochlea basal turn(BT)line-middle sagittal line,the cochlea BT line-external auditory canal(EAC)line,the EAC line-middle sagittal line,and the vertical distance between the facial nerve(FN)and the EAC line on the RW accessibility.The angle between the RW-FN connection line and the coronal line passing through the FN,the vertical distance between the RW and the line,the position relation between the extension line parallel to the EAC and the RW,and the position relation between the extension line and the FN on the RW accessibility was statistically significant.Conclusion The difficulty of RW exposure in CI is correlated to smaller angle between the RW-FN connection line and the coronal line passing through the FN,and closer vertical distance between the RW and this coronal line.The RW accessibility can be predicted by the position relation between the extension line parallel to the EAC and the RW and the position relation between the extension line parallel to the EAC and the FN.