神经导航辅助幕上下乙状窦前经部分迷路锁孔入路的解剖学研究

目的在神经导航辅助下,设计幕上、下乙状窦前经部分迷路锁孔入路,探讨精确磨除入路相关骨质结构的可行性,为临床应用提供依据。方法采用8具经40％甲醛固定、颅内动静脉乳胶灌注的成入尸头,实验前建立术中导航资料。在导航系统中用不同颜色标出重要结构的范围。采用迷路后锁孔手术入路的耳后7cm“C”型切口,分层翻开皮瓣和肌筋膜瓣,做耳后约3．5cm×3cm骨窗,在神经导航辅助下轮廓化乙状窦、骨半规管、面神经管,磨除部分迷路及岩尖,观察部分迷路及岩尖磨除前后显露结构的差异,测量术野范围和乙状窦前间隙最大术野角度。结果（1）迷路后锁孔入路的切口完全满足经部分迷路锁孔入路的要求。（2）神经导航可辅助精确磨除入路相关骨质,减少盲目磨除造成的重要结构的误伤。（3）该入路可广泛显露岩斜区、桥脑小脑角、桥脑前区和海绵窦后部的重要结构。（4）部分迷路及岩尖磨除后的水平视野为：左侧（18．8±1．6）mm）,右侧（17．7±1．2）mm;最大术野角度为：左侧（59．3±9．2）°,右侧（57．0±11．0）°。垂直术野的增加值为：左侧（10．0±1．0）mm,右侧（10．0±0．8）mm。双侧术野范围和最大术野角度的增加值差异均有统计学意义（均P〈0．01）。结论幕上、下乙状窦前经部分迷路锁孔入路具有可行性;磨除部分迷路及岩尖可显著增加术野范围和术野角度。

Anatomic study of the supra-infratentorial presigmoid partial labyrinthectomy keyhole approach assisted by neuro-navigation

OBJECTIVE: To design a new supra-infratentorial presigmoid partial labyrinthectomy keyhole approach assisted by neuro-navigation system, and to explore the possibility of removing the approach-correlated bone precisely. METHODS: Navigation data were established on 8 cadaveric heads fixed by formalin and perfused intracranial vessels with colored silicone. Before the operation, the important structures were outlined with different colors in the navigation system. A 7-cm "C" shape skin incision was performed 1cm behind the helix. On elevating the skin flap and musculofascial flap respectively, a 3.5 cm x 3 cm bone window was performed. After skeletonized the sigmoid sinus, bony labyrinth and the canal for facial nerve assisted by neuro-navigation, the amount of dura exposed and the maximal angle of vision were measured before and after partial labyrinthectomy with petrous apicectomy, the anatomic structures were observed as well. RESULTS: The incision of the supra-infratentorial retrolabyrinthine keyhole approach fully met the needs of the presigmoid partial labyrinthectomy keyhole approach. The approach-correlated bone could precisely be drilled with the aid of neuro-navigation, which could avoid the bewilder in drilling process. This approach provided wide exposure to petroclival region, cerebellopontine angle, prepontine region and posterior cavernous sinus. After partial labyrinthectomy with petrous apicectomy, the horizontal exposure was increased to (18.8 +/- 1.6) mm (left side) and (17.7 +/- 1.2) mm (right side); the maximal angle of vision was increased to (59.3 +/- 9.2) degrees (left side) and (57.0 +/- 11.0) degrees (right side); the vertical exposure increased (10.0 +/- 1.0) mm (left side) and (10.0 +/- 0.8) mm (right side); there were significant differences between before and after partial labyrinthectomy with petrous apicectomy (P < 0.01). CONCLUSION: It is feasible to perform the supra-infratentorial presigmoid partial labyrinthectomy keyhole approach. The exposed field and the maximal angle of vision can be obviously increased by partial labyrinthectomy with petrous apicectomy.