乙状窦后和乙状窦前入路微创显露颈静脉结节的虚拟现实对比研究

Comparative study of retrosigmoidal and presigmoidal approaches for minimally invasive exposure of jugular tubercle using a virtual-reality technique

目的在构建虚拟现实解剖模型基础上,量化比较乙状窦后和乙状窦前入路微创显露颈静脉结节的显微解剖特征。方法 15例(30侧)尸头行CT和MRI扫描,影像数据输入虚拟现实系统构建颅后窝三维解剖模型。在颅盖和颅底中选择骨性标志点模拟乙状窦后和乙状窦前入路微创路径,观察和测量两种手术路径中解剖结构显露情况,采用配对t检验进行比较分析。结果乙状窦后入路由横窦下方开颅,包含小脑半球和小脑前下动脉,到达颈静脉结节时,路径包含舌咽、迷走、副神经和岩下窦。乙状窦前入路由乳突磨除岩骨,经过颈静脉球下端和颈内静脉,到达颈静脉结节时,包含部分副神经。测量手术路径和后组脑神经体积:乙状窦后入路>乙状窦前入路;路径中骨性结构和静脉体积:乙状窦前入路>乙状窦后入路,差异均有统计学意义(P<0.05)。乙状窦后入路中包含小脑半球体积为(2750.50±123.27)mm3、小脑前下动脉体积为(78.72±1.75)mm3,乙状窦前入路不包含上述结构。结论乙状窦后入路有利于显露后组脑神经,显露过程应注意保护小脑和小脑前下动脉。乙状窦前入路显露颈静脉结节时,受到磨除岩骨操作和保护静脉窦的限制,适于处理累及颈静脉孔的病变。

Objective To quantitatively compare microanatomical features of minimally invasive exposure of jugular tubercle via retrosigmoidal and presigmoidal approaches based on anatomy model of virtual reality. Methods CT and MRI scans were performed on 15 adult cadaver heads （30 laterals）. Then, image data was inputted into virtual reality system to establish three-dimensi0nal anatomy model of the posterior cranial fossa. Minimally invasive routes of retrosigmoidal and presigmoidal approaches were simulated by selecting osseous landmarks on the calvaria and skull base. Anatomic exposures in above two surgical trajectories were observed and measured. A statistical comparison was performed by paired t test. Results Craniotomy via retrosigmoidal approach was performed below the transverse sinus. The route involved the cerebellum and anterior inferior cerebellar artery （AICA）. Then, the route exposed the glossopharyngeal nerve, vagus nerve, accessory nerve and inferior petrosal sinus. Surgical route of presigmoidal approach involved drilling of the osseous structures through the mastoid, and the accessory nerve when arrived at the jugular tubercle through the internal jugular vein and inferior part of jugular bulb. Measuring showed volumes of the surgical route and lower cranial nerves were larger in the retrosigmoidal approach than in the presigmoidal approach. The volumes of the osseous structures and veins were larger in the presigmoidal approach than in the retrosigmoidal approach. All these differences reached statistical significance （P 〈 0.05）. The volume of the cerebellum and AICA involved in retrosigmoidal approach was 2750.50 ± 123127 mm3 and 78.72 ±1.75 mm3 respectively. The presigrnoidal approach did not involve above structures. Conclusions Retrosigmoidal approach is helpful to expose the lower cranial nerves, and cerebellum and AICA should be protected during the exposure. The procedure of jugular tubercle exposure through presigmoidal approach will be confined by operation ofpetrous bone drilling and sinus protection. The presigmoidal approach is suitable for treating the lesion involving jugular foramen.