内镜下经筛蝶入路视神经减压术的应用解剖

The applied anatomical study for transethmoidal-sphenoid optic nerve decompression under endoscopy

目的研究内镜下经筛蝶入路视神经减压术的相关解剖以及在手术中的意义。方法手术显微镜下解剖福尔马林固定的成人尸头视神经管标本15例（30侧），观察视神经管的解剖特点和毗邻关系，并根据鼻内镜入路测定相关参数。结果①视神经颈内动脉三角（optic carotid triangle，OCT）与视神经、眼动脉、海绵窦和颈内动脉关系恒定，OCT出现率为66．7％。②鼻小柱基底前缘到视神经管眶口、管中部和颅口内侧缘的距离分别为（72．79±5．40）mm、（75．85±5．10）mm和（79．34±4．95）mm，仰角分别为（39．45±3．68）°、（37．30±4．24）°和（35．45±4．16）°。③视神经内侧壁眶口、管中部和颅口的鞘膜厚度分别为（0．70±0．18）mm、（0．51±0．15）mm和（0．49±0．22）mm，眶口与管中部、颅口差异有统计学意义（P〈0．01）；④视神经管眶口、管中部和颅口内侧缘离颅正中矢状面的旁开距分别为1／2（12．69±2．73）mm、1／2（19．61±3．47）mm和1／2（25．79±3．23）mm。结论OCT是内镜下经筛蝶入路视神经减压术首选的解剖定位标志．减压关键在视神经眶口，从视神经内侧壁与上壁交界处切开鞘膜安全且容易操作。

Objective To explore the anatomy for transethmoidal-sphenoid optic nerve decompression under endoscopy and its significance in operation. Methods Fifteen cases （30 sides） of formalin-fixed adult optic canal specimens were dissected under the microscope. The anatomic characteristics of the optic canal and its adjacent were observed, and the relative parameters were evaluated according to nasal endoscopic approach. Results （1）The relationship between the optic carotid triangle（OCT）with the optic canal, the ophthalmic artery, the cavernous sinus and the internal carotid artery were invariable, its present ratio were in 66.7%. （2）The mean distance from the front margin of nasal columella floor to medial wall of the orbital opening, middle portion and the cranial opening in the optic canal were （72.79 ±5.40）mm, （75.85±5.10）mm and （79.34 ± 4.95）mm, respectively, and the elevation angles were （39.45 ± 3.68）°, （37.30±4.24）° and （35.45 ± 4.16）°, respectively. （3）The mean thickness of sheath in the medial walk of the orbital opening, middle portion and the cranial opening were （0.70 ± 0.18）mm, （0.51 ± 0.15）mm and （0.49 ±0.22）mm, respectively. The difference in thickness between the orbital opening and middle portion, the cranial opening were very remarkable（P 〈 0.01 ）. （4）The lateral deviate distance from medial wall of the orbital opening, middle portion and cranial opening to sagittal median plane of cadaveric were 1/2 （12.69 ± 2.73）mm,1/2（19.61 ± 3.47）mm and 1/2 （25.79 ±3.23）mm, respectively. Conclusion OCT is the most reliable anatomic landmark to locate the optic canal, and the key point is at the orbital opening of the optic nerve in the optic nerve decompression. It is secure and feasible to cut the sheath from the place where the medial wall crosses the superior wall of the optic nerve.