鞍区手术相关的视交叉区域解剖及其临床应用

Anatomy of the optic chiasma and its surrounding structures in saddle area operation.

目的为脑底肿瘤压迫视交叉引起视野缺损原因提供依据，为鞍区手术提供形态基础。方法研究80例成人脑视交叉及其相邻的鞍隔、垂体、颈内动脉及其穿支小动脉的形态、毗邻。结果视交叉的前角，最大角度为100°，以前置型多见；最小角度40°，以后置型为主；面积平均（1．32±0．04）cm^2。鞍隔厚度平均（0．58±0．09）mm，缺如的占5％；鞍隔孔偏向一侧的占52．5％，最大孔径7．8mm×9．8mm；垂体低于鞍隔孔的占78％（62／80）；颈内动脉与视交叉相接触的占76．3％（61／80）。结论垂体瘤、颅咽管瘤在早期引起不同类型的视野缺损的原因与视交叉及其周围结构的形态直接相关。

Objective To provide morphological evidences for visual field defect caused by the compression of the saddle area tumors. Methods The shape and position of the optic chiasma and its surrounding saddle diaphragm , pituitary,internal carotid artery, and perforating arteries of optic chiasma were studied from 80 adult. Results Its maximum angle was 100°in anterior horn with prechiasmatic space, and minimum angle was 40° with postfixed optic chiasma. The area of optic chiasma averaged （ 1.32 ±0. 04 ） cm^2, the thickness of saddle diaphragm was 0.58 mm ,and about 5% of saddle diaphragm did not exist. The foramen of saddle diaphragm pushed into the opposite side was 52.5% ,and the maximum diameter was 7.8 mm ×9.8 mm. The pituitary was found inferior to the saddle diaphragm foramen in 78% （62/80）. In 76.3% （61/80） brains, the carotid artery touched chiasm opticum. Conclusions Visual field defect caused by compression from pituitary tumor and craniopharyngioma is directly related with the shape of the optic chiasma and its surrounding structures.