Experimental Study On The Mechanism Of Liver Regeneration In Rats With Hepatic Fibrosis After Associating Liver Partition With Portal Vein Ligation For Staged Hepatectomy(ALPPS)

Objective:To establish a stable rat model with hepatic fibrosis for associating liver partition and portal vein ligation for staged hepatectomy?ALPPS?and investigate the mechanisms on regeneration of future remnant liver in rats.Methods:1.Establishment of a rat model of hepatic fibrosis:50 SD male rats?100±20g?were injected subcutaneously with 50%carbon tetrachloride?CCL₄?-Olive oil mixture for six weeks?0.3ml/100g,every 6 days?.At the eighth week,we evaluated the overall survival rate and stage of liver fibrosis with Ishak.Then,we performed partitial hepatectomy?80%?and assess the postoperative survival rate.2.This experiment divided into two groups:Fibrosis group and Normal group.24 rats for each group.At 1,3,5 and 7 days after ALPPS,six rats of each group were sacrificed.The second period surgery was performed after 3 days of the first period.At each time point after surgery,we detected the Ishak fibrosis scorings of Fibrosis group,the postoperative survival rate and complication of stepI and stepII of ALPPS.The future remnant liver and body weight of rats after surgery were acquired for assessment of hepatic regeneration rate.Then,we observe the morphism and amounts of hepatocyte by HE staining,and analyze the proliferation index by obtaining the positive expression of Ki-67.At last,we dectected the serum levels of ALT,AST,ALB and TBIL.Results:1.Thesurvivalrateof hepatic fibrosis rats was 96%.We can find hyperplasia of fibrous tissue,P-P septa and P-C septa around the most portal area by HE and Masson staining.The Ishak fibrosis stage was between 3-5,and mean value was 3.81±0.76.The rats which underwent partitial hepatectomy?80%?were all died in 24h after surgery.2.The Ishak stage of the Fibrosis group was between 3-5,and mean value was 3.63±0.92.There was no significant difference between eachpoint-in-time?P>0.05?.The survival rate of the Fibrosis group after step I of ALPPS is 93.1%,while step II is 88.9%,and the total survive rate of ALPPS is 82.8%.Similarly,the survival rate of the Normal group after step I is 96.3%,while step II is 92.3%,and the total survival rate is88.9%.There was no significant difference between these two groups?P>0.05?.The postoperative complication includes hemorrhage,acute hepatic failure,bile leakage and infection.At 1,3,5 day after ALPPS in the fibrosis group,hepatocyte hypertrophy was occured and the mean amounts of hypertrophy in each field of vision were decreased after surgery,there was significantly difference between preoperation and each time point of postoperation?P<0.05?.While there is no significant hepatic hypertrophy after ALPPS in the normal group The hepatic regeneration rate of Fibrosis group was significantly decreased than Normal group after the 5d?P<0.05?.And in the other time point,the difference was no significant in both groups?P>0.05?.The Positive index of Ki-67 of Fibrosis group at 5d was significantly higher than Normal group?P<0.05?,while there was no significantly difference at 1,3,7d?P>0.05?.The serum level of ALT and AST were increased in both Fibrosis group and Normalgroup.Then,cometonormallevelsat7dafter ALPPS.Moreover,Fibrosis group was higher than Normal group at 3d?P<0.01?.While,there was no significantly difference at the other time points?P>0.05?.There was no significantly difference of ALB and TBIL at each point-in-time?P>0.05?.Conclusion:1.This experiment established a stable and repeatable rat model ofhepatic fibrosis by subcutaneous injection.In addition,it also successfully provide a reliable model to complete the later period of abdominaloperation.The rats with hepatic fibrosis?Ishak 3-5?cannot underwent partitial hepatectomy?80%?in one period.2.This experiment successfully established a stable model of ALPPS in rats with hepatic fibrosis.The feasibility and safety of Fibrosis were approximated to Normal group.These datas provide a powerfultheoretical foundation for the extension of indications of hepatic fibrosis in ALPPS.3.The Fibrosis group can significantly accelerate hepatic regeneration by hepatocyte proliferation and hypertrophy after ALPPS.This experiment provided a novel idea for the reseach of future remnant liver regeneration of ALPPS with hepatic fibrosis.