乙状窦前和乙状窦后入路微创显露膝状神经节的虚拟现实比较

目的：通过虚拟现实技术比较乙状窦前和乙状窦后入路微创显露膝状神经节的显微解剖特征。方法对15例尸体头颅行M RI和C T扫描，将影像数据输入虚拟现实系统，构建颞骨三维解剖模型，在颅盖和颅底选择骨性标志点勾勒乙状窦前和乙状窦后入路显露膝状神经节的手术路径。观察两种路径的解剖结构空间形态和顺序，测量解剖组织体积，采用配对 t检验进行比较分析。结果乙状窦前入路由乳突开始磨除岩骨，避开乙状窦和颈静脉球，经过面神经垂直段、听骨链、迷路，到达膝状神经节时，显露面神经。乙状窦后入路由横窦下方开颅，经过小脑半球，到达内听道时磨除岩骨，经过面听神经复合体，到达膝状神经节，路径中包含听骨链和迷路。手术路径和迷路体积测量：乙状窦后入路＞乙状窦前入路；面听神经复合体和听骨链体积：乙状窦前入路＞乙状窦后入路，差异均有统计学意义（P ＜0．05）。乙状窦后入路中小脑半球体积为（462．72±20．87）mm3，乙状窦前入路不包含小脑半球。两种路径中骨性结构（不包含听骨链）体积的差异无统计学意义（P＞0．05）。结论在磨除岩骨显露膝状神经节的路径中，乙状窦前入路有助于减少迷路损伤范围，乙状窦后入路有助于减少听骨链损伤范围并显露面听神经复合体。

Comparison between presigmoidal and retrosigmoidal approaches for exposing geniculate ganglion utilizing virtual reality skill

Objective To compare microanatomy feature for exposing geniculate ganglion between presigmoidal and retrosigmoidal minimally invasive approaches by virtual reality technique .Methods CT and MRI scans were performed to 15 adult cadaver heads ,then image data was inputted into virtual real‐ity system to establish three -dimensional anatomy model of temporal bone .Surgical routes of presig‐moidal and retrosigmoidal approaches exposing geniculate ganglion were outlined by selecting osseous landmark points on the calvaria and skull base .Special form and sequence of anatomic structures were observed .Volumes of anatomic tissues were measured .Statistical comparison was launched by paired t test .Results Bone drilling through presigmoidal approach started with mastoid and avoided injury of sigmoid sinus and jugular bulb .The surgical route involved vertical segment of facial nerve ,ossicular chain ,labyrinth ,and then ,exposed facial nerve when arrived at geniculate ganglion .Routes simulating sigmoidal approach passed below the transverse sinus and lateral to cerebellum .When arrived at internal acoustic meatus ,the route performed bone drilling for petrous bone and involved facial -acoustic nerve complex .When reached geniculate ganglion ,the ossicular chain and labyrinth were exposed in the route . Measuring showed that the volumes of surgical route and labyrinth were larger in retrosigmoidal ap‐proach than those in presigmoidal approach .Volumes of facial -acoustic nerve complex and ossicular chain were larger in presigmoidal approach than those in retrosigmoidal approach .All above differences reached statistical significance (P < 0 .05) . Volume of cerebellum in retrosigmoidal approach was (462.72 ± 20 .87) mm3 .Presigmoidal approach did not involve cerebellum .NO significant differences were found in the volumes of osseous structures (not include ossicular chain ) between two approaches (P > 0 .05) .Conclusions To expose geniculate ganglion by petrous bone drilling ,presig‐moidal approach is helpful to reduce the injury of labyrinth .Retrosigmoidal approach is helpful to reduce the injury of ossicular chain and expose facial -acoustic nerve complex .