兔局灶性脑缺血微导丝法预处理模型的建立

Intraluminal thread approach in making focal cerebral ischemia preconditioning model in rabbits

目的:探讨稳定的兔局灶性脑缺血预处理微导丝法模型的建立及对其评价。方法:健康新西兰白兔35只,随机分为3组:假手术组5只;缺血组10只,在DSA引导下,选择微导丝直接从颈总动脉(CCA)经颈内动脉(ICA)插至大脑中动脉(MCA)起始部4 h,再灌注时,抽回导丝至颈总动脉内;预处理组20只,在DSA引导下,选择微导丝从颈总动脉经颈内动脉插至MCA起始部停留15 min,再灌注时,抽回导丝至颈总动脉内停留15 min,如此重复3次,之后将微导丝堵于大脑中动脉起始部4 h,完成微导丝法局灶性脑缺血预处理模型的制作,并利用神经功能缺损评分、TTC和HE染色对模型进行评价。并且对模型行MRI常规扫描及弥散成像,分析MRI是否也能显示脑缺血预处理的存在。结果:血管造影可清晰显示颈内动脉的走行及其颅内分支情况,8只(80%,8/10)动物缺血模型成功,12只(60%,12/20)动物脑缺血预处理模型成功。缺血/再灌注后3 h就可在T2WI,DWI表现为右侧海马及外侧基底节区高信号,DWI范围大于T2WI,于24 h T2WI范围基本不变且T2WI与DWI范围相近。TTC染色将正常组织染成红色,梗死脑组织不染色而呈白色,不染色的范围与导丝栓塞后T2WI上的病变范围基本一致,预处理组最终T2WI上高信号区及TTC无染区体积均小于缺血组。结论:采用微导丝直接从颈总动脉经颈内动脉插至MCA起始部,栓塞15min后,抽回导丝至颈总动脉内再灌注15 min,如此反复3次,能建立较稳定的脑缺血预处理模型。

Objective ： To investigate reproducibility of intraluminal thread approach in making focal cerebral ischemia/reperfusion preconditioning model in rabbits. Methods： Thirty-five rabbits were randomly divided into three groups： Control group（ n = 5）was sham-operated. Ischemiac group（n = 10）, focal cerebral ischemia/reperfusion model was made under DSA by inserting a wire into MCA through ICA and CCA directly and pulling it out 4 hours later. The method of preconditioning group （ n = 20） was similar to that of ischemiac group, just pulling the wire out 15 minutes and pushing it in 15 minutes, 3 times repeatly, then pulling it out 4 hours later. Neurological deficit score, TFC and H-E were used to evaluate the effectiveness of models. Whether could MRI confirm the existence of preconditioning too？ Results： The course and bifurcation of ICA could be displayed clearly on the angiography. Eight in ten of ischemiac group and twelve in twenty of preconditioning group（ sixty percent） were successful models. High signal was seen on DWI and T2WI 3h after ischemia/reperfusion. White area of TIC matched the high sign area of T2WI,but the infarction volume of preconditioning group was less than ischemiax group. Conclusion： Focal Cerebral ischemia preconditioning model made by inserting a wire into MCA through ICA and CCA directly and pulling it out 15 minutes and pushing it in 15 minutes,3 times repeatly was stable and fit for imaging research.