家兔行无腔静脉转流术安全阻断时限研究

Safe Interval for Blocking Superior Vena Cava during Non Vena Cava Bypassing Operation in Rabbits

目的:研究家兔行无腔静脉转流术时,术中直接阻断上腔静脉的安全时限。方法:50只家兔,随机分为5组,每组10只,雌雄各半,Ⅰ组为单纯开胸手术对照组;Ⅱ组为上腔静脉阻断30 min组;Ⅲ组为上腔静脉阻断45 min组,Ⅳ组为上腔静脉阻断60 min组,Ⅴ组为上腔静脉阻断90 min组,阻断结束时测量上腔静脉压力并取各组脑组织固定后HE染色,镜下观察脑组织水肿情况。结果:将Ⅱ、Ⅲ、Ⅳ、Ⅴ组与对照组比较,Ⅱ组阻断30 min未出现水肿,P>0.05,差异无统计学意义;Ⅲ组阻断45 min组,其中2例轻度水肿,P>0.05,差异无统计学意义;Ⅳ组阻断60 min,7例出现水肿,P<0.05,差异有统计学意义;Ⅴ组阻断90 min,10例均出现水肿,P<0.05,差异有统计学意义。结论:无腔静脉体外转流条件下,兔上腔静脉阻断的安全时限在45 min以内。但当时间超过30 min,出现脑水肿的风险逐渐增加,当阻断时间达60 min或以上时,对于实验动物非常危险。

Objective：To investigate the safe interval for directly blocking superior vena cava during non vena cava bypassing operation in rabbits.Methods：A total of 50 rabbits were randomly divided into 5 groups,10 rabbits （half male and half female） in each group.For group Ⅰ,simple thoracic surgery was implemented; For group Ⅱ,Ⅲ,Ⅳ and Ⅴ,time for interruption of superior vena cava was 30,45,60 and 90 minutes respectively ; At the end of interruption,the superior vena cava pressure was measured and the brains of the rabbits were adopted and fixed,and the degree of the brain tissue edema was observed after HE staining under a microscope.Results：Compared with group Ⅰ,edema of brain tissue was not found in group Ⅱ （P 〉 0.05） ; 2 cases of mild edema in group Ⅲ were found,there was no obvious difference still（P 〉0.05） ;7 cases of edema in group Ⅳ were found,the difference was obvious （P 〈 0.05） ; The brains of all the cases in group Ⅴ were edematous,obvious difference were found （P 〈 0.05）.Conclusion：The superior vena cava of rabbit can be interrupted for 45 minutes during the operation of non-vena cava-bypassing.But when the blocking time is more than 30 min,the risk of brain edema gradually increased,and when blocking time is up to 60 min or above,it is very dangerous to the experimental animals.