经乙状窦前入路的脑干腹侧区微创手术的虚拟解剖学研究

Virtual reality anatomy of minimally invasive surgery for ventral brian stem through presigmoidal approach

目的在虚拟现实系统中探讨乙状窦前入路显露脑干腹侧的微创手术路径解剖特征。方法对15例尸体头颅行头颅CT和MRI扫描,影像数据输入虚拟现实系统构建颈静脉孔区三维解剖模型,选择骨性结构和颅神经出脑干处的标志点绘制圆柱模拟经岩骨乙状窦前入路显露脑干腹侧的手术路径,观察测量和比较显露脑干腹侧不同部位的路径中解剖结构空间构筑情况。结果模拟经岩骨乙状窦前入路显露脑干腹侧的路径中清晰显示所包含的神经、血管等解剖结构的空间层叠顺序,三维影像模型中所测路径中岩骨骨性结构体积:路径b>路径c>路径a,后组颅神经体积:路径c>路径b>路径a,路径a中包含静脉和小脑前下动脉体积最大,面听神经复合体体积:路径b>路径a,面神经垂直段体积:路径c>路径a,差异均有统计学意义(P<0.05)。路径中迷路体积路径b和路径c比较差异无统计学意义(P>0.05)。结论虚拟现实系统有助于理解乙状窦前入路显露脑干腹侧不同靶点时途径骨性结构、神经、血管等的空间构筑关系。

Objective To investigate the anatomy features of minimally invasive surgical trajectory to expose ventral brain stem in transpetrosal-presigmoidal approach based on virtual reality image model. Methods CT and MRI scanning was performed to 15 adult cadaver heads, and then the obtained image data were inputted into Vitrea virtual reality system to establish 3-D anatomy model of jugular foramen region. Transpetrosal-presigmoidal approach exposing ventral brain stem was simulated by selecting osseous and root entry zoon of cranial nerve as landmark points to draw a cylinder. Anatomic exposures in surgical trajectory following alternation of different minimally invasive approaches were observed, measured and compared. Results Spatial sequence of nerves and vessels in the route simulating transpetrosal-presigmoidal approach to expose ventral brain stem was displayed clearly. The volume measuring for petrous bone in 3-D image model showed： route b 〉 route c 〉 route a, and that for lower crania] nerves showed： route c 〉 route b 〉 route a. The volumes of veins and anterior inferior cerebellar artery were largest in the route a, that of facial-acoustic nerve complex in the route b was larger than that in route a, and that of vertical segment of facial nerve in the route c was larger than that in route a （ all P 〈 0.05 ）. No significant difference was seen in the volume of labyrinth between the route b and c （ P 〉 0. 05 ）. Conclusion Virtual reality system is of great help to understand the spatial architecture relationship among osseous structures, nerves and vessels involved in presigmoidal approach to expose different targets of ventral brainstem.