Current Status and Future of Liver Transplantation

Liver transplantation has rapidly advanced from an experimental therapy to a mainstream treatment option for a wide range of acute and chronic liver diseases. Indications for liver transplant have evolved to include previously contraindicated conditions such as hepatocellular carcinoma and alcohol-related liver disease. Cirrhosis from chronic hepatitis C infection remains the most common indication today. Multidisciplinary evaluation for liver transplantation is intended to confirm the patient's suitability and identify the appropriate timing of transplant, although the latter is problematic as a result of the ongoing donor organ shortage. Deceased liver donors have been increasing in number, but increasing donor age has been associated with less satisfactory posttransplant results. Living donor liver transplant is a dramatic but very infrequent procedure; risk to the living donor is of paramount concern. The main focus of deceased donor allocation has transitioned from waiting time to estimation of the likelihood of death without transplant (medical urgency), and now relies upon a laboratory-based Model for End-Stage Liver Disease (MELD) score for candidates with chronic liver disease. Those with acute liver failure are prioritized ahead of those with chronic conditions. Although not used as a direct criterion for allocation, development of the concept of transplant survival benefit, i.e., the extra years of life attributable to transplant, has facilitated better ordering of those candidates likely to have the most benefit, while restricting access to those whose lives will be extended minimally or not at all. Overall posttransplant outcomes have steadily improved, with unadjusted 5-year patient survival rates of 77% among patients transplanted with MELD score between 15 and 20, and 72% for those with MELD scores between 21 and 30.