幕上下锁孔联合入路岩斜区显微解剖

Combined supra-and infra-tentorial surgical keyhole approach to petroclival region:microanatomy

目的研究幕上下锁孔联合入路对岩斜区的暴露,并探讨神经内镜的应用。方法尸头上分别模拟颞下、枕下锁孔手术,颞下以颧弓支前1/3上方钻孔,铣一直径约25 mm圆形骨窗,枕下以星点稍前方钻孔,铣一直径约30 mm骨窗,显微镜下暴露观察;神经内镜下行岩斜区探查;导航下标记操作空间,行CT薄层平扫及三维重建。结果①颞下术野可暴露脚间池、同侧环池、桥前池幕上区、鞍旁、鞍上池及中颅窝,小脑幕切开后,幕下桥前池及环池下部得以显露;由于岩尖的遮挡,脑桥小脑角池显露不佳;岩斜区操作空间均值3.38 cm3;②枕下术野可暴露脑桥小脑角池、后部环池、桥前池;碍于内听道上结节、岩骨嵴及岩尖遮挡,麦克氏囊入口到海绵窦后部为术野死角;岩斜区操作空间均值2.27cm3;③麦克氏囊入口到海绵窦后部仍为联合入路术野死角,空间均值0.89 cm3,神经内镜下可暴露。结论①颞下锁孔、枕下乙状窦后锁孔术野岩斜区暴露存在互补性;②麦克氏囊入口到海绵窦后部为联合入路死角区,空间范围较小;③神经内镜下可暴露死角区,但操作间隙小,手术可行性尚需探讨;该区肿瘤残存率低,行伽马刀治疗安全有效。

Objective To study the exposure of combined supra-and infra-tentorial surgical keyhole approach to petroclival region,and investigate the application value of neuroendoscopy. Methods Subtemporal and suboecipito- retrosigmoid sinus keyhole approaches were modified respectively in 20 sides of adult wet cadaveric heads injected with silicone. The exposure to petroclival region was examined under microscope and probed with neuroendoscopy. The suitable operating zone were labelled under neuronavigation and then three-dimensional reconstructed on CT scan. Results ① A good vision to interpeduncular cistern, ipsilateral ambient cistern, the upper part of the pre- pontine cistern, parasella, suprasellar regions and the middle cranial fossa could be obtained via subtemporal ap- proach. Incision of the tentorium exposed the inferior part of prepontine cistern and ambient cistern. A way to the eerebellopontine angle cistern could not be acquired due to the blocking effect of petrous apex. The volume mean of exposing to petroclival region was 3.38 cm3. ② Suboccipito-retrosigmoid sinus approach has a good view to cere- bellopontine angel cistern, posterior ambient cistern and prepontine cistern, and its exposed volume mean was 2. 27 cm3. ③ The space from the posterior part of the cavernous sinus to the opening of Mecl^el＇s cave was a blind angle for combined approach and its volume mean was 0.89 cm3, which could be sion ① The two approaches mentioned above have good complementation. the cavernous sinus to the opening of Meckel＇s cave is a blind angel and it could be exposed under neuroendoscopy, on which the operation feasibility space. Gamma knife is safe and effective for small tumor remnants. exposed with neuroendoscopy. Conclu- ② The space from the posterior part of covers small space. ③ The blind angle still needs to be discussed due to small