乙状窦后入路显露靶点对手术创伤影响的虚拟现实解剖测量

Impact of target exposure via retrosigmoidal approach in surgical injury measured by virtualreality skill

目的在构建虚拟现实解剖模型基础上探讨乙状窦后入路显露靶点对手术创伤的影响。方法根据15例尸头的CT和MRI数据构建岩骨三维解剖模型．在颅盖和颅底中选择骨性标志点设计乙状窦后入路对不同靶点进行显露的手术路径：路径a显露颈静脉结节前缘．路径b显露内听道外口上缘，路径c显露岩尖。观察不同手术路径中解剖结构的空间形态和顺序，测量并比较解剖组织体积。结果所有路径均由横窦下方穿过，经过小脑半球外侧．路径a显露后组颅神经和小脑前下动脉，到达颈静脉结节时显露岩下窦；路径b显露小脑前下动脉、迷路和面听神经复合体；路径c经过岩上窦内侧，显露面听神经复合体，到达岩尖时显露三叉神经、小脑上动脉和海绵窦。不同手术路径、颅神经、骨性结构、小脑、动脉体积不同，差异有统计学意义（P〈0．05）。路径c、路径a、路径b的手术路径和颅神经体积依次降低；路径C、路径b、路径a中包含的骨性结构体积依次降低；路径b、路径a、路径c中包含小脑体积依次降低；路径a、路径c、路径b中包含动脉体积依次降低，差异均有统计学意义。路径a中静脉体积[（68．91±1．91）mm3]低于路径C中静脉体积[（248．92±11．26）mm3]，差异有统计学意义（1==-90．274，P=-0．000），路径b中不包含静脉结构。结论颅底显露靶点对乙状窦后入路经过解剖组织结构的范围影响显著，通过测量组织体积能够客观评价创伤和显露的关系。

Objective To discuss the impact of target exposure via retrosigmoidal approach in surgical injury based on virtual reality anatomic models. Methods CT and MR imaging data of 15 adult cadaver heads were utilized to establish three-dimensional anatomy models of petrous bone. Surgical routes exposing different targets though retrosigmoidal approach were simulated by selecting osseous landmark points on the calvaria and skull base. Special form and sequence of anatomic structures in different routes were observed. Volumes of anatomic tissues were measured. Results All the surgical routes passed below the transverse sinus and lateral to the cerebellum. Route a exposed the lower cranial nerve and anterior inferior cerebellar artery; when reached the jugular tubercle, the route exposed inferior petrous sinus. Route b exposed the anterior inferior cerebellar artery, labyrinth and facial-acoustic nerve complex. Route c passed the medial to the superior petrous sinus and exposed the facial-acoustic nerve complex; when being arrived at petrous apex, the route exposed the trigeminal nerve, superior cerebellar artery and cavernous sinus. The volumes of the lower cranial nerve, osseous structures, cerebellum and artery were significantly different in models adopted different routes （P〈0.05）; the volumeof the lower cranial nerve was as follows： route c〉route a〉route b, the volume of osseous structures was as follows： route c 〉route b〉route a, the volume of cerebellum was as follows： route b 〉route a〉route c, and the volume of artery was as follows： route a 〉route c〉route b. Venous structure involved in route a （[68.91±1.91] mm3） was larger than that in route c （[248.92±11.26] mm3） with statistical significance （P〈0.05）, and route b did not involve venous structure. Conclusions Targets in skull base has significant impaction on the size of anatomic structures involved in the route of retrosigmoidal approach. Relationshio between injury and exnosure can be evaluated objectively by the volume measurement.