视束血供形态学研究及其临床意义

Morphology study of blood supply to optic tract and its clinical significance

目的 :研究视束动脉起源、数量、分布以及相关动脉的病理变化 ,为视束因缺血所致视野缺损提供形态学依据。方法 :在体视显微镜和手术显微镜下 ,对 45例 90侧成人脑标本进行观察 ,研究视束动脉的起源、数量、分布 ,对其中 5 0～ 70岁年龄的 60侧脑标本的视束相关动脉做病理切片观察。结果 :视束的血供主要来自颈内动脉、大脑中动脉、大脑前动脉、后交通动脉、和脉络丛前动脉的分支 ,呈节段性分布 ,上述动脉有动脉粥样硬化改变者占 88.3 % ,动脉粥样硬化斑块引起视束动脉完全阻塞的占 6.7% ( 4侧 ) ,部分阻塞的占 5 .0 % ( 3侧 )。结论 :5 0岁以上者出现一过性或持续性不同程度的视野缺损 ,若除外其他疾患则可能是脑底动脉粥样硬化引起视束血供障碍所致。

Objective: To provide morphological evidences for visual field defect caused by optic tract ischemia. Methods: The origins, numbers, distributions and pathological changes of optic tract arteries of 90 sides' adult brain specimens were observed with micro-stereoscope and operating microscope, and the nutrient artery of optic tract of 60 sides aged from 50 to 70 were observed pathohistologically. Results: The blood supply to optic tract originated mainly from internal carotid artery, middle cerebral artery, anterior cerebral artery, posterior communicating artery and the branch of anterior choroidal artery, which distributed segmentally. 88.3% of these arteries in 60 sides had atherosclerosis. The optic tract arteries of 4 sides were completely blocked and 3 sides partly. Conclusion: Excluding other diseases, the temporary or consistent visual field defect in different degree of patients over 50 years old is caused possibly by atherosclerosis of the arteries at the base of the brain.