多次缺血预处理诱导脑侧枝循环重建对脑缺血保护的实验研究

目的采用多次压迫阻断右侧颈总动脉的缺血预处理，并逐次递增缺血时间，诱导右侧大脑侧枝循环建立，观察其对脑缺血的保护作用。方法家兔48只，采用随机数字法分为对照组和实验组，每组24只。实验组实验期间实施球囊充气阻断颈动脉血流，每次压迫时间为：次缺血时间=次数×5+40(min)进行，每日2次，直到压迫时间达4 h（总时间为...

Experimental study of cerebral ischemia protection of cerebral collateral circulation reconstruction induced by multiple ischemic preconditioning

Objective We used ischemic preconditioning method by blocking rabbit's right carotid artery at intervals repeatedly and increasing blocking time to reconstruct collateral circulation. Cerebral protection effects were investigated after the right carotid artery was permanently blocked. Methods 48 rabbits were randomly divided into experimental and control groups (n=24).The right common carotid artery of the animals in the experimental group was compressed at intervals repeatedly. We blocked the right carotid artery blood flow by the Inflatable balloon, ischemic time=number of times×5+40(min), 2 times per day. The longest blocking time is 4 h (20th days). The procedure of control group was the same as that of experimental group, except that the carotid artery blood flow was not blocked. The establishment of a right collateral circulation in the rabbit brain was observed with Digital Subtraction Angiography (DSA) on the 1st, 10th and 20th day respectively. The blood flow in the right common carotid artery was completely blocked at 20th day. The neurological deficit score was observed at 1, 3, 6, 24 h. Then we got brain tissue specimens and compared the brain water content and pathological changes between the two groups. The number of brain microvascular of the corresponding places was also counted. Results During the experiment, no abnormal behaviors such as excitement, agitation, lethargy were observed in either group. DSA showed that contrast medium passed into the right middle cerebral artery Willis ring on the 10th day.Compared with the 1st day, the blood vessels on the right side were much clearer in DSA. On the 20th day there was almost no difference between the left and right sides in vascular imaging. Experimental group's neurological deficit score and water content were lower than those of the control group's (P＜0.05). Observation showed that there were more brain microvascular in the right side (ischemic side) pathological specimens of the experimental group 5.3±0.5 than control group 3.5±0.4 (P＜O.05) under microscope at 400 times. Conclusion By multiple ischemic preconditioning cerebral artery Willis ring and cerebral collateral circulation would be reconstructed, and it had obvious protective effect on cerebral ischemia resulted from completely blocked carotid arteries.