Development of an improved rat model of dual graft liver transplantation with long-term survival.

Dual graft liver transplantation has been demonstrated to be feasible as well as effective in increasing the donor pool and in preventing the potential for small-for-size syndrome. However, little is known about the pathophysiological and immune processes following dual graft liver transplantation due to the lack of appropriate animal models. The aim of this study, therefore, was to establish an improved rat model of dual graft liver transplantation, with long-term survival. Male inbred rats were used as both donors and recipients. One middle lobe together with another right middle lobe from the livers of two different donors were used as the dual grafts. The "basin-shaped anastomosis" technique was used to connect the suprahepatic inferior vena cava; "Y-shaped bridge" and "three-cuff" techniques were adopted for the anastomosis of the portal veins; and the "two-stent" technique was used for the anastomosis of the bile ducts. Six of the ten recipients survived for more than 100 days after dual graft liver transplantation. There was no difference in graft survival between dual and whole liver transplantation. The long-term survivors with dual grafts from two different donors had unobstructed portal vein flow, unobstructed biliary tract dilatation, normal graft function, and well-preserved hepatic structure. Therefore, this improved model will be potentially useful for evaluating the pathophysiological processes, immune responses between dual grafts and recipient, and mechanisms underlying the liver regeneration in dual grafts after dual graft liver transplantation.