低温快速冷冻对大鼠损伤动脉的影响

Effect of cryopreservation on injured arteries

目的研究快速低温冷冻解除在体损伤动脉痉挛及其对在体损伤动脉的影响。方法以钳夹法建立并筛选出适当的在体损伤动脉模型,将60只标准在体动脉损伤大鼠模型随机分成3组,罂粟碱组以3％罌粟碱局部解除痉挛；冷冻组以快速低温冷冻解除痉挛；对照组不做任何处理。分别观察即时的解痉效果和60d后动脉的通畅情况。结果 1．即刻解痉情况：对照组解痉率为0,罌粟碱组解痉率为65％,冷冻组解痉率为100％。冷冻组与罌粟碱组痉挛解除率两组差异有统计学意义(P<0．05)。2．长期血管通畅率：对照组为55％,罌粟碱组为60％。冷冻组为87．3％。

Objective To study the effect of cryopreservation on injured arteries. Methods Bilateral femoral artery injury model was set up by clamping the artery in 60 Sprague Dawley rats. These 60 animals were divided into 3 groups according to different treatment of the injured arteries. In group A gauze soaked with 3 % papaverine was applied on top of the bilateral femoral arteries for 5 minutes. In group B the arteries were treated by rapid low- temperature freezing method in vivo. Group C served as control without any treatment to the clamped arteries. Immediate responses were observed before wound closure. 60 days later, The arteries were exposed for observation of patency and for histologic study. Results Spasm was seen in all the arteries immediately following arterial clamping. Topical applleation of papaverine relieved spasm in 26 arteries out of 40 in group A. Cryo-treatment relieved spasm of all 40 arteries in group B. There was statistically significant difference in spasm relieving between group A and B （X^2= 4.211, P 〈 0.05） , No spasm relief was seen in group C. 60 days later, the patency rates for groups A, B, and C were 60 % （24/40）, 87.25% （35/40）, and 55 % （21/40） respectively. There was statistically significant difference in spasm relief rate between group A and B （ X^2 = 7. 813, P 〈 0. 10, ） Histology of the patent arteries showed smooth and intact endothelium, There was mild subendothelial collagen fiber proliferation. The internal elastic layer remained normal. Sporadic smooth muscle cell proliferation was seen at the media. Histology of cryo-treated arteries revealed reduced thickness of smooth muscle layer and slight disorientation of the muscle cells. Focal proliferation of fibrose tissue and smooth musele cells can be seen occasionally. Inflammation infiltration still existed at the adventitia. No narrowness, thrombosis and aneurysm were seen. Conclusions Spasm of moderately injured arteries can be reversed by cryo-treatment. These cryo-treated arteries can be repaired with a decent patency rate.