[Lateral endoscopic transorbital approach to middle skull base: anatomical and surgical practice study].

Objective: To investigate the anatomical and surgical approaches to middle cranial fossa through orbital lateral wall under endoscope. Methods: Cadaveric formalin fixed specimens and fresh colored silicone injected specimens were used for this study. All anatomic technical measurements were performed under 0° and 30° endoscope and infrared rays navigation. The surgical approach was designed with the bony opening on the lateral wall of orbit through which the lateral side of the middle cranial fossa could be directly entered under endoscope. One case of recurrent meningioma was performed through this surgical approach. SPSS 20.0 software was used for statistical analysis. Results: The approach can directly enter the middle cranial fossa and expose anatomic landmarks including superior orbital fissure, lateral side of cavernous sinus, foramen rotundum, foramen ovale, foramen spinosum, petrosal bone and others as well as Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ cranial nerves under endoscope. The maximal bony opening through the lateral wall of orbit was measured, with a horizontal diameter of (1.38±0.68) cm, a vertical diameter of (2.02±0.32) cm, a depth of (1.44±0.42) cm from bony opening margin to the dura. The recurrent meningioma involving lateral side of the middle skull base was successfully removed by this surgical approach through lateral wall of orbit. Conclusion: Lateral transorbital endoscopic approach to the lateral side of middle skull base is a safe, feasible, and minimally invasive method, which allows surgeons to directly manipulate diseases involving this area with good visualization and minimal invasion under endoscope.目的： 探讨内镜下经眼眶外侧壁中颅底解剖及手术入路方法。 方法： 采用甲醛溶液固定尸头及新鲜灌注尸头进行解剖及手术入路研究，利用0°、30°内镜及红外线导航进行解剖标志及径线的定位和测量，设计直接经眼眶外侧壁骨性开口进入中颅底外侧的入路方式，采用此入路行复发中颅底外侧脑膜瘤手术1例。应用SPSS 20.0进行统计学分析。 结果： 经此入路可以充分暴露中颅底外侧结构，包括眶上裂、海绵窦及颈内动脉外侧、圆孔、卵圆孔、棘孔、岩骨等，并可充分暴露并保护第Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ颅神经。经眼眶外侧壁最大骨窗的横径为（1.38±0.68）cm，垂直径为（2.02±0.32）cm，外侧骨缘至硬脑膜骨窗深度为（1.44±0.42）cm；复发脑膜瘤患者利用此入路可顺利暴露并大部切除中颅窝肿瘤。 结论： 内镜下经眼眶外侧壁入路为直接到达中颅底外侧区并处理此部位病变提供了一个可行的微创、安全、有效的方法，可以使术者更加清晰地处理中颅底外侧区域病变。.