The Experimental Study About The Effects Of Portal Vein Arterialization And Cavo-portal Transposition On Liver Regeneration After Partial Hepatectomy In The Rat

【objective】1. To establish a new, viable, repeatable, stable rat models of portal vein arterialization and Cavo-portal transposition,for providing the animal models to study the effect of different portal perfusions on liver regeneration.2. To discuss the effect of liver regeneration after 40 percent hepatectomy for rat models of portal vein arterialization and Cavo-portal transposition,and evaluate the effect on liver regeneration of two perfusions.【methods】1. Establish the rat model of portal vein arterialization:based on the mothod of cuff, the model of portal vein arterialization were established in 40 rats use by the allogeneic vascular and cuff. Removing left kidney, reconstruct the blood flood between left renal artery and portal stump by allogeneic vascular,connect the superior mesenteric vein and left renal vein by the cuff.The liver function,pathology,weight, survival rate and MRI were observated after surgery.2. Establish the rat model of Cavo-portal transposition: the model of Cavo-portal transposition were established in 40 rats use by the dubble-side cuff.Shearing the inferior vena cava on the level of right renal vein,and shearing the portal vein of the first branch, reconstruct the blood flood between left renal vein and portal stump by cuff,connect the superior mesenteric vein and inferior vena cava by the dubble-side cuff. The liver function,pathology,weight, survival rate and MRI were observated after surgery.3.Establish the models of portal vein arterialization and Cavo-portal transposition after 40 percent hepatectomy:on the base of above-mentioned two models,resect the rat liver 40 percent(the left hepatic lobe and nipple lobe).90 rats were randomly selected of total 100 rats,and were randomly divided into three groups,30 rats for each group.Group A: portal vein arterialization plus 40 percent hepatectomy;Group B: Cavo-portal transposition plus 40 percent hepatectomy;Group C:the control group,转left kidney nephrectomy and 40 percent hepatectomy.Another 10 rats were evaluated the remant liver weight after 40 percent hepatectomy.There were three time points for 3,7,14 day after surgery.Each points 10 rats were randomly selected to observe indicators:portal vein pressure,liver function,the capacity of remant liver regeneration,HE staining,Immunohistochemical staining for Ki-67 and TUNEL, Transmission electron microscopy.4.Statistical analysis: Measurement data expressed as mean±standard deviation (x±s).The data were analyzed through SPSS18.0 software. One-way ANOVA, t test,analysis were applied. Pairwise comparisons use the LSD procedures. P<0.05 was considered statistically significant.【Results】1. Assessment about the rat model of portal vein arterialization and Cavo-portal transpositionTwo models are established successfully. Success rate of the portal vein arterialization(PVA) is 97.5%,the Cavo-portal transposition(CPT) is 95%,the survived rats live two month after surgery.One month after surgery,the value of ALB,ALP, Cholinesterase and weight are no significant difference between the experimental group and control group. Two month after surgery,the portal vein patency rate of the PVA was 94.9%,compared to 84.2% of the CPT.There are no obvious abnormalities on the MRI angiography and pathology between the two models.2. The influence of liver regeneration after 40 percent hepatectomy between two ways of Portal vein perfusion.2.1 The surgery success rate of Group A and C was 100%,compared to 96.7% of Group B.The portal vein pressure of Group A was increased significantly vs the Group C,the Group B was decreased significantly at 14^th day. The value of ALT of the Group A was decreased significantly at 3^rd day,compared to the Group B was increased at 14^th day. The values of ALB and ALP were no significant difference among the three groups.The liver regeneration rate of Group A was increased significantly vs the Group C at 3^rd and 7^th day,the Group B was decreased significantly at all time points.2.2 Pathology:The HE staining of Group A showed that the hepatic sinusoid and interlobular vein expand significantly;Group B showed that there were much fatty degeneration and apoptosis in hepatocyte,and lymphocytes in portal area;Group C were normal.The Ki-67 labeling index of Group A increased significantly compared to Group C at 3^rd day,the index of the Group B decreased after 7^th day but increased at 14th day compared Group C.The apoptosis index of Group B was higher than Group C at 3^rd and 7^th day.2.3 Transmission electron microscopy:There are much mitochondria and dubble-nuclear cells in Group A.The hepatocyte nuclear chromatin of Group B was slightly condensed, and rough endoplasmic reticulum were mild degranulated,some apoptotic cells can be seen.Group C were normal.【Conclusion】1.The rat model of portal vein arterialization,which established by the allogeneic artery and cuff technique and had a high portal vein patency,was a feasible,stable,simple and reproducible model.2.The rat model of Cavo-portal transposition,which established by the superior vena cava dubble-side cuff and cuff technique with short operative time and high success rate, was a feasible,stable and simple model.3.In the experiment of portal vein arterialization plus 40 percent hepatectomy,we find that the valve of ALT was lower than Group C, however,the valve of Cholinesterase, liver regeneration rate and Ki-67 labeling index were higher and there were more mitochondria in early postoperation,which showed the PVA can enhance the hepatic energy metabolism and regeneration capacity, and improve survival rate.4.In the experiment of Cavo-portal transposition plus 40 percent hepatectomy,we find that there were no difference in liver function at early postoperation, but the valve of liver regeneration rate and Ki-67 labeling index were lower than Group C,and the apoptosis index were higher.Thus, it showed that the ability of Cavo-portal transposition were weaker than the port vein arterialization on energy metabolish,regeneration capacity and surgical tolerance at early partial hepatectomy.