Results from early experimentation with hepatic homotransplantation were discouraging. The technical procedures used for insertion of the homograft carried a high risk (30, 60, 61, 82, 83, 102). The first efforts to potentiate homograft survival with immunosuppressive drugs or whole body irradiation were relatively unsuccessful (62, 84, 90, 91). More recently, laboratory experimentation has conclusively shown that homotransplantation of the liver can be carried out in dogs with success comparable to that attainable with the kidney (93). The purpose of this account is to describe such advances in liver homotransplantation as they have evolved from laboratory studies, with proper emphasis on that unique body of information which could be obtained only by clinical trial.

In the past, important steps were made toward characterizing the microscopic features of the liver homograft, principally early after transplantation. Unfortunately, the pathologists who studied various features of the problem had access to only one phase of the over-all picture. Some reviewed the histologic changes following orthotopic transplantation to the untreated (10, 51, 61, 83) or treated (62, 90, 91) dog; others described the changes after auxiliary canine homotransplantation in which the homograft is placed in a heterotopic site and the animal’s own liver retained (30, 33, 54, 66, 77, 91, 99,102), and still others described human liver homotransplants relatively early after operation (62, 88–91). For the present report, an attempt was made to review all tissues available from our previous transplantation research. In this way, the pathologist among us (KAP) was able to obtain a complete picture of the early and late changes in both the host and the liver homograft (58, 72, 93).