Study Of The Tolerance Limit Of Normothermic Hepatic Inflow Occlusion By Meso-caval Shunt In Bama Swines

Objective: An animal model of hepatic inflow occlusion with meso-caval shunt in Bama swines was established and the tolerance limit of normothermic hepatic inflow occlusion was evaluatedMethods: 18 Bama swines were randomly divided into two groups with 9 animals in each group,Hepatic inflow was occlused for 90min in group A, Animals in group B underwent hepatic inflow occlusion of 100min.The survival state of these Bama swines after operation was observed, and liver function tests were performed during the period of hepatic blood inflow occlusion and the reperfusion. The liver biopsy was used to evaluate the degree of liver damage by light microscope.Results : (1) The survival rate of group A and B was 100% and 44.4%, respectively;(2)Compared with the pre-ischemia, the ALT levels of two groups after ischemia and at 1h after reperfusion were not significantly changed(P>0.05).However, on postoperative 2d and 3d, the ALT level was significantly increased(P<0.05). On postoperative 4d, the ALT level recovered to normal level(P>0.05).ALT level of group B was significantly higher than that of group A on postoperative 2d and 3d(P<0.05);(3) AST levels of two groups reached peak at lh after reperfusion (P<0.05), and recovered to normal level on postoperative 3d (P>0.05). AST level of group B was significantly higher than that of group A at lh after reperfusion and on postoperative 1d and 2d (P<0.05);(4)The levels of GGT, ALP and ALB during occlusion, after referfusion were not significantly changed compared with those before ischemia(P>0.05),and there were no statistical difference between the two groups ( P > 0.05);(5)The T-BIL and D-BIL levels of the group A at ischemia 90min were significantly higher compared with the levels before ischemia(P<0.05), then decreased to the normal level(P>0.05). The T-BIL, D-BIL levels of the group B reached peak after 100min of ischemia (P<0.05), and returned to normal level on postoperative 5d(P>0.05). T-BIL and D-BIL levels of the group B were significantly higher than those of group A at the end of ischemia, lh after reperfusion and onpostoperative l-4d (P<0.05);(6)Hepatic injury was more sever at pre-reperfusion than at the pre-ischemia(P<0.05). The hepatic tissue injury was more sever than that at pre-reperfusion at lh after reperfusion(P<0.05). The hepatic tissue recovered to normal in group A on postoperative 4d (P>0.05), however, hepatic necrosis was found in swines that were dead in group B.Conclusion: (l)We have established an animal model of hepatic inflow occlusion with meso-caval shunt in Bama swines without the mesenteric congestion which can reflect the degree and time cause changes of the damage during hepatic ischemia-reperfusion more accurately.(2) Hepatic injury was more sever with the prolongation of ischemia time. The injury level reached peak at lh after reperfusion, the hepatic tissue of the long-term surviving animals recovered to normal on postoperative 4d. The changes that focal necrosis, massive ballooning degeneration and lipoid degeneration occured after ischemia may indicate that the animal can not tolerate the I/R injury. (3) AST is the better index which can reflect the damage degree of the hepatic I/R injury than the other correlated liver function parameters.(4) 90min is the tolerance limit of normothermic hepatic inflow occlusion in swine under conditions of meso-caval shunt.