Long-term survival of auxiliary partial liver grafts in DLA-identical littermate beagles

Auxiliary heterotopic transplantation of 60% of the liver in the beagle, using a technique in which all requirements for optimal graft survival are met, is described. The autologous liver is left in situ. Transplants were performed in non-tissue-typed and matched donor-recipient combinations. Postoperatively the recipients were treated with a standard schedule of 2 mg azathioprine and 1 mg prednisolone i.v. daily for 75 days--thereafter, the immunosuppressive drugs were gradually withdrawn. HIDA-hepatobiliary scanning proved to be useful for the assessment of graft function. In eight non-tissue-typed donor-recipient combinations, median graft survival was 7 days, most transplants being subject to acute rejection. However, in nine experiments in which donor and recipient were DLA-identical littermates, the median graft survival was 112 days (P less than 0.005). In these animals signs of chronic rejection developed after tapering the immunosuppressive drugs. It is concluded that, in this model, graft survival is improved by histocompatibility matching. The feasibility of partial heterotopic liver transplantation indicates that this method must be reconsidered for clinical application, especially for patients with acute liver failure. For the recipient, it is a relatively minor operation that--by its temporary life sustaining function--may allow for the regeneration or restoration of function of the recipient's own liver.