Opportunities and costs of clinical research.

Orthotopic hepatic transplantation offers selected patients a surgical cure of their otherwise hopelessly advanced liver disease. It also presents the medical-scientific community with an almost limitless list of new questions to be asked, unique materials to be studied, and an opportunity to extend the current understanding of liver disease and its complications. Presented below is a list of five major areas of research that orthotopic liver transplantation has made possible, the list certainly is not all-inclusive. These topics have been selected as examples of the investigative areas in liver disease that should benefit dramatically as a consequence of the increasing performance of the procedure and the involvement of more and new investigative groups in transplant programs. They are: (1) preservation of the liver; (2) hepatic regeneration; (3) the pathogenesis of various unusual metabolic liver diseases; (4) the immune mechanisms involved in rejection as well as in various primary hepatic diseases; and (5) the problem of hepatic encephalopathy, its pathogenesis, consequences, and reversibility. Each of these major areas of investigative interest to hepatologists and hepatic surgeons will be discussed individually.