Experimental Study Of The Effects Of Partial Portal Vein Arterialization On Hilar Bile Duct In Rats

Background and objects:In recent years, it is reported that patients with hilar cholangiocarcinoma increased year by year. Radical surgery for hilar cholangiocarcinoma is also increasing. Hepatic artery resection is often involved in radical surgery for hilar cholangiocarcinoma because it is also invaded by tumor. Hepatic artery reconstruction may be difficult or even impossible due to short arterial stump, narrow diameter or wide anatomical variation. A large number of animal experiments and clinical reports suggest that the approach of partial portal vein arterialization (PPVA) to reconstruct artery blood flow of the liver can significantly improve the liver metabolism and regeneration.It also improve liver and bile duct oxygen supply,prevent liver failure after radical surgery for hilar cholangiocarcinoma.In this study,we establish a rat model of partial portal vein arterialization. To study effects of the approach on hilar bile duct in rats,in order to provide application foundation for the wide clinical use of this approach.Methods:1. To establish experimental models:partial portal vein arterialization+hilar bile duct reconstruction (PPVA group,the blood of liver and hilar bile duct were supplied completely by PPVA) and hepatic artery ligation+hilar bile duct reconstruction (HAL group, the blood of liver and hilar bile duct were supplied by portal vein),sham-operated rats served as controls.2.SMA labeling immunohistochemistry was performed to evaluate arteriolar counts changes of peribiliary vascular plexus(PVP) of the hilar bile duct wall.Serum biochemical and pathologic changes of the bile duct were observed 1 month after operation.3.Terminal deoxy-nucleotide transferase-mediated deoxy uridine triphosphate (Dutp) nick end labeling (TUNEL) and PCNA labeling immunohistochemistry were performed to evaluate proliferation and apoptosis of rat hilar bile duct epithelial cells.Results:1.Compared to hepatic artery ligation+hilar bile duct reconstruction group,the PVP arteriolar count of the hilar bile duct was higher in PPVA+hilar bile duct reconstruction group.The result has statistically signifcant difference. No statistically signifcant differences in alanine aminotransferase(ALT), aspartate aminotransferase(AST), alkaline phosphatase(ALP) and albumin (ALB) were found in the 3 groups. The gamma-glutamyltransferase (GGT) value was higher in HAL+ hilar bile duct reconstruction group than in PPVA+hilar bile duct reconstruction group and Control group. The result has statistically signifcant difference.2. No apoptotic hilar bile duct epithelial cells were detected in any of the groups. The proliferation of hilar bile duct epithelial cells in HAL+hilar bile duct reconstruction group was greater than in PPVA+hilar bile duct reconstruction group and Control group.The result has statistically signifcant difference.3. Chronic infammatory changes in the hilar bile duct walls were observed only in HAL+hilar bile duct reconstruction group.The alignment of biliary epithelial cells was in disarray with local cell loss and cytoplasmic vacuolation accompanied by infltration of infammatory cells and remarkable proliferation of goblet cells.Conclusions:1. In this study, we not only ligated the hepatic artery and its branches, but also excised the bile duct for recanalization in designing our model. Meanwhile, all perihepatic ligaments were severed to ensure that the liver and bile duct received their blood supply only from the portal vein.we successfully induced bile duct ischemia in rats.2. Partial portal vein arterialization can improve ischemia and anoxemia of the liver and bile duct after hepatic artery ligation,reduce incidences of postoperative ischemic disorders of bile duct,improve chronic inflammation caused by HAL,promote early recovery of bile duct physiological function and hepatic function and does not induce cholangiocyte apoptosis.It is a safe and effective short-term surgical approach.