Histological changes in the rat liver following orthotopic liver transplantation with and without graft rearterialization: A time course study

We have previously found significant bile duct proliferation in the liver 8 weeks after liver transplantation without arterial reconstruction, which was absent in the rearterialized graft (Zhao et al. [1993] Hepatology 17 : 301-317). The object of this study was to determine if these changes were time-related. Liver transplantation was performed in male Lewis rats under ether anaesthesia. After 3 days, 1, 4, 8 weeks and after 6 months the livers were harvested, subjected to systematic random sampling, and processed for quantitative morphometry and semiquantitative histology. Untreated control animals were also included. Bile duct damage and ductular proliferation were already present at 3 days after transplantation without rearterialization and were more extensive after 1 week. At 8 weeks early stage fibrosis was present in this group. In contrast, the rearterialized liver had an intact lobular structure at all time points although some bile duct proliferation and cellular infiltration were noted. No significant differences from controls were found for any parameter. In the non-rearterialized liver, the hepatocyte volume fraction was decreased and those for the bile duct and nonhepatocyte parenchyma were increased. In addition, connective tissue appeared at 8 weeks after transplantation without rearterialization. These findings indicate that an intact arterial supply to the graft is necessary for the maintenance of hepatic structure after liver transplantation in the rat.