兔急性上腔静脉梗阻的安全时限

目的 探讨新西兰大白兔耐受上腔静脉梗阻时间,为临床上腔静脉重建术中阻断安全时限提供依据.方法 新西兰大白兔25只,对照组5只,阻断上腔静脉1 h手术组和2 h手术组各10只,观察上腔静脉压变化,并比较3组术后脑含水量百分比、脑组织的病理学改变.结果 (1)阻断后兔上腔静脉压呈"上升-下降-再上升-维持"过程;(2)阻断1 h组脑含水量与对照组无明显差异,阻断2 h组脑含水量较对照组明显升高,亦较阻断1 h组高;(3)阻断1 h组脑组织结构基本正常,脑细胞病变轻;阻断2 h组可见脑水肿改变,神经元坏死.结论 成功建立急性上腔静脉梗阻动物模型,阻断兔上腔静脉1 h相对安全,阻断2 h以上将产生脑水肿及神经元坏死等改变.

The animal experiment for acute superior vena cava obstruction

Objective To investigat the safe time of SVC interruption in New Zealand rabbits, and help to find the safe time ofSVC interruption in chnical operation. Methods 25 New-Zealand rabbits were separated into 3 groups randomly. Bi-SVC was cross-clamped for one hour, two hours in animal models. The femoral artery or SVC pressures were monitored. The control group (sham op-eration group, 5) were opened chest both sides and monitored femoral artery pressure and SVC pressure for 2 hours. Samples of cere-brum, cerebellum and medulla of rabbits immediately post-operation were studied for water content, light and electric microscopies.The tiny change of brain cells in brain mantle, hippocampus and thalamencephal were observed under electron microscope. Results(1) The SVC pressure of rabbits varied regularly in occlusion groups, which displayed as "upgrade-degression- upgrade again-retain".(2) There was no obvious difference in water content of brain between the one hour group and the control group, both of which weremuch lower than two hours group. (3) The brain tissues were almost in normal construction in one hour group, but encephaledema wasobserved in two hours group. The pathological change of cony brain cells was light and reversible in one hour group. However, in twohours group, necrosis of neuron ceils in brain could be observed, which was irreversible. Concerto The animal model of acuteSVC obstruction was built successfully. Interruption of the SVC for 1 hour was proved safe, with longer interruption of SVC 2 hours,obvious encephaledema and necrosis of neuron cells can be observed.