ABSTRACT
PURPOSE: The portal blood influx appears to be essential for liver regeneration after a liver resection and transplant. It was reported that only grafts with a gastro-pancreatic-splenic portal inflow into the graft portal vein could increase in size. The aim of this study was to investigate the impact of the gastro-pancreatic-splenic portal flow on the regeneration of a graft liver in a microsurgical model of heterotopic partial liver transplantation model. METHODS: Sprague-Dawley rats weighing 200 to 300 grams were used in this study. The rats were fasted for 12 hours prior to surgery. Thirty percent of the liver was heterotopically transplanted, to connect the donor's portal vein and suprahepatic vena cava with the recipient's superior mesenteric vein and the suprarenal vena cava, respectively. The donor and original liver were weighed preoperatively and 1, 2, 3, 7 days postoperatively. In addition, the histology of the donor and recipient's liver were examined using optical microscopy, and H & E staining. The proliferative capacity of the donor and recipient hepatocytes was evaluated using immunohistochemistry. RESULTS: The liver weights of the donor and recipient were measured at serial time points after surgery. Progressive enlargement was observed in the original liver. However, in assessing the liver weight, the weight of the donor liver was significantly lower at 2 days, 3 days, and 7 days after surgery than that of the original liver. During the observation periods, prominent histopathological differences were observed between the donor and recipient liver. There was a markedly higher number of PCNA (+) cells in the original liver than in the donor liver. CONCLUSION: The gastro-pancreatic-splenic portal inflow into the graft appears to play an important role in regenerating a partial liver graft. However, several variables such as the ischemic time, bile duct ligation, a small-for-size graft, and hepatic artery reconstruction in this model should be considered.