Da-Zhi Chen

Risk factors of severe ischemic biliary complications after liver transplantation

BACKGROUND Ischemia-related biliary tract complications remain high after orthotopic liver transplantation. Severe ischemic biliary complications often involve the hepatic duct bifurcation and left hepatic duct, resulting finally in obstructive jaundice. Prevention and management of such complications remain a challenge for transplant surgeons. METHODS All 160 patients were followed up for at least 180 days after transplantation. One-way analysis of variance (ANOVA) and comparative univariate analysis were made using 3 groups (no complications; mild complications; severe complications), to analyze risk factors associated with biliary complications. Multiple logistic regression and linear regression analysis were used to analyze independent risk factors for severe ischemic biliary complications, after excluding other confounding factors. RESULTS By ANOVA and comparative univariate analysis, the risk factors associated with biliary complications were preoperative bilirubin level (P=0.007) and T-tube stenting of the anastomosis (P=0.016). Multiple logistic regression analysis showed that the use of T-tube and preoperative serum bilirubin were not independent risk factors for severe ischemic biliary complications after orthotopic liver transplantation. Chi-square analysis indicated that in the incidence of severe ischemic biliary lesions, bile duct second warm ischemic time longer than 60 minutes was a significant risk factor. Linear regression demonstrated a negative correlation between cold preservation time and warm ischemia time. CONCLUSIONS Preoperative serum bilirubin level and the use of T-tube stenting of the anastomosis were independent risk factors for biliary complications after liver transplantation, but not for severe ischemic biliary complications. The second warm ischemia time of bile duct longer than 60 minutes and prolonged bile duct second warm ischemia time combined with cold preservation time were significant risk factors for severe ischemic biliary complications after liver transplantation with grafts from non-heart-beating donors.

Establishment of an Animal Model of Biliary Ischemic Stenosis With Clamping in Mice

OBJECTIVE The objective of this study was to explore a method to establish biliary ischemic stenosis in mice. METHODS After the optimal time of biliary ischemia was determined, 20 Kunming mice were equally divided into 2 groups. In the experimental group a 0.4-cm length of common bile duct was clamped for 90 minutes with 2 micro-vessel clamps (width = 0.1 cm). The common bile duct was not clamped in the control group. Twenty-one days later, biliary tract visualization was performed in all mice. Blood samples were collected from the inferior vena cava to determine the serum levels of total bilirubin (TBIL) and alanine aminotransferase (ALT). Meanwhile, samples of the common bile duct and liver tissue were extracted for microscopic examination to observe morphological changes. RESULTS In the experimental group, obvious dilatation of the common bile duct appeared over the clamp site. There was no dilatation of the common bile duct in the control group. Twenty-one days later, serum levels of TBIL and ALT were significantly higher among the experimental compared with the control group. Microscopic examination showed that the part of common bile duct at the clamp site was significantly expanded, with a smaller or occluded bile duct lumen necrotic mucosa with determination, and tubular wall with fibrosis and excrustation. A few dead liver cells and many inflammatory cells were observed in liver tissue samples. CONCLUSIONS A biliary ischemic stenosis model was established using a clamping method in mice, which may provide a reliable technique for basic and clinical research into mechanisms of biliary ischemic stenosis after liver transplantation.