单侧颈动脉结扎后脑缺血及相关因素分析

An experimental study on predicting the cerebral ischemia after the left common carotid artery occlusion in gerbils

目的 研究单侧颈动脉结扎后脑病理生理变化及其相关因素。方法 结扎沙土鼠左颈总动脉( CAL )。结扎前后测定双侧脑电能量 ( P) ,计算结扎后左右 P之比占结扎前的百分率 ( r P)。测量结扎远近端血管直径 ,计算其比值 ( D)。术后解剖脑底血管 ( A) ,电镜观察脑组织超微结构 ( U ) ,流式细胞仪定量分析脑细胞死亡率( C)。结果 CAL后 ,3 3 .3 %( 10 / 3 0 )的动物出现神经系统并发症 ( S)。症状组 D、r P、C分别为 5 8.6%± 6.9%、5 2 .3 %± 16.6%和 3 0 .4 %± 2 4 .6%。无症状组分别为 75 .5 %± 6.6%、87.8%± 7.0 %和 5 .9%± 2 .4 %。r P、D、C相互间均呈显著相关。缺乏前交通动脉 ( ACo A )的动物都出现了 S;但有 ACo A动物中也有 9.1%( 2 / 2 2 )出现 S。无症状组中有个别表现为细胞变暗、染色质异常凝集 ,症状组则呈不同程度脑缺血表现。结论 CAL后 S与其 A有关 ,而 U和 C可由 D及 r P推测。

Objective To study the physiopathological effect of the brain after unilateral carotid artery ligation (CAL) and its relative factors. Methods The Mongolia gerbil was used to monitor electroencephalograph powers before and after the left common carotid artery ligation. The vessel diameters distal and proximal to the ligation site were registered. After CAL,the circle of Willis was anatomized,the ultra-structural alteration of the brain cell was observed with electronic-microscope,and the death rate of the brain cell (C) was quantified with fluid cytometer. Results Following the CAL,10/30 subjects developed neurologic impairment. In symptomatic group,the distal diameter (D) was 58.6%±6.9% of proximal one,the L/R ratio of electroencephalograph power (rP) was 52.3%±16.6% of that pre-ligation and the C was 30.4%±24.6%; while those in asymptomatic group were 75.5%±6.6%,87.8%±7.0% and 5.9%±2.4% respectively. There was a significant linear correlation between D,rP and C. No gerbil without anterior communication artery (ACoA) was noted asymptomatic,though 2/22 gerbils with ACoA were induced symptomatic. By electron microscopy,increased electron density neurons and clumped nuclear chromatins were delineated in some of the asymptomatic group; whereas a variety of degrees of ischemic changes were showed in the symptomatic group. Conclusion The neurologic symptom after CAL is relevant to the anatomic type of the circle of Willis. The D and rP contributed to the C and ultrastructural alterations.