视交叉的血液供应及其临床意义

THE BLOOD SUPPLY OF CHIASMA AND ITS CLINICAL SIGNIFICANCE

用手术显微镜观测了24例成人视交叉的动脉,并用墨汁明胶灌注和透明的方法,在立体解剖镜下观察了3例胎儿视交叉内部的微血管构筑.分布至视交叉的小动脉为视交叉上动脉、视交叉内侧动脉和外侧动脉,前两者在视交叉周围和软膜内形成两级丰富吻合.视交叉实质中部的毛细血管密度低、吻合少、网眼大,呈左右横向排列,为微循环的薄弱环节.当鞍区病变时,此部首先受累,以致出现特征性双颞侧视野缺损.

The blood vessels of optic chiasma were obseved and measured in 24 adult brains under operation microscope, and the microvasculature of optic chiasma of 3 fetuses treated with ink-gelatin injection and transperency was studied under stereoscope. The arteries distributed in the optic chiasma included the superior chiasmatic artery, the medial chiasmatic artery and the lateral chiasmatic artery. The former two formed rich anastomoses of two levels at the surrounding of chiasma and pia mater. The middle portion of chiasma, where there were lower density, less anastomoses, bigger network and transverse arrangement of capillaries, was a weak point of microcirculation. When the blood supply of chiasma was interfered by sella tumour, it was susceptible to being affected and became so ischemic that the characteristic bitemporal visual field defects might appear.