Objective To validate the mechanism of effect of hepatic artery ischemia on biliary fibrosis after liver transplantation and the prevention method. Methods Eighteen male dogs were established into the concise auto orthotopic liver transplantation models and assigned into three groups randomly: hepatic artery ischemia (HAI) group, TBB group (transferred the blood by a bridge duct ) and control group, each group contained 6 dogs. After opening portal vein, the samples were cut from liver in each group at the time of 6 h, 3 d and 14 d. The pathological modifications of intrahepatic bile ducts were observed and expression of transforming growth factor-β1 (TGF-β1) were detected in the three times. Expressions of Smad3 and phosphate-Smad3 as well as mRNA of α-smooth muscle actin (α-SMA) in intrahepatic bile ducts were detected 14 d after opening portal vein.Results Compared with control group, the collagen deposition and lumens stenosis in biliary vessel wall were more obviously in HAI group. In TBB group, the pathological modifications were slighter compared with HAI group. The positive cell index of TGF-β1 reached peak on day 3 after opening portal vein, then decreased in TBB group, and which in HAI group kept increase and was significantly higher than that in TBB group （Plt;0.05）. The expression level of phosphate-Smad3 and transcriptional level of α-SMA mRNA were 1.04±0.13 and 1.12±0.55 in TBB group on day 14 after opening portal vein, which were significantly higher than those in control group (0.59±0.09 and 0.46±0.18) and lower than those in HAI group (1.82±0.18 and 1.86±0.73), the diversities among three groups were significant (Plt;0.05). There was not significant difference of expression of Smads among three groups (Pgt;0.05). Conclusions Hepatic artery ischemia could increase the deposition of collagen fibers and the transdifferentiation of myofibroblast in bile duct and result in the biliary fibrosis by activating the TGF-β1/Smads signaling pathway. The bridging bypass device could lessen the biliary fibrosis caused by hepatic artery ischemia by inhibiting the activation of TGF-β1/Smads signal transduction passageway.
【Abstract】Objective The injury induced by hepatic artery ischemia (HAI) in the liver transplantation procedure and the protective effects of using hepatic artery bridge-conduit (HABC) technique were studied. Methods Thirtytwo dogs were randomly divided into 4 groups: control, HAI 30 min, HAI 2 h and HABC groups. We observed the pathological changes of hepatocytes and biliary tract tissues and the microstructure of chondriosome, which were based on the model of auto-orthotopic liver transplantation in dogs. Biochemical and spectrophotometric methodswere used to evaluate the content of MDA and SOD, SDH activities in the graft liver tissue respectively. Results The pathologic and electrical microscopic changes of hepatocytes and epithelial cells of bile ducts were found in HAI 30 min and HAI 2 h groups,while the content of MDA increased to （1.652±0.222） nmol/mg prot and (2.379±0.526) nmol/mg prot, and SOD activity decreased to (11.15±3.9) U/mg prot and (9.47±3.4) U/mg prot. At the same time, SDH activity was also down-regulated to 0.362±0.019 and 0.281±0.029. Compared with control group, the differences were significant (Plt;0.05, Plt;0.01). But these changes of functional index caused by HAI injury were not significant in HABC group. Conclusion The HABC technique can not only avoid HAI injury during operation but also alleviate the occurrence of complication after transplantation, especially the biliary tract complication.