MELD-based liver allocation: who is underserved?

Deceased-donor livers are a scarce, lifesaving resource. For patients whose lives depend upon liver transplantation, policies for prioritizing allograft allocation are of ultimate importance. In the current paradigm, donor livers are allocated on the basis of medical urgency. Thus, the onus is on the transplant community to refine the allocation system continuously so that livers are targeted to patients who need them most. The current model for end-stage liver disease (MELD)-based allocation system works well, accurately predicting short-term mortality for the majority (83 to 87%) of waitlisted candidates. However, there are patients with liver diseases whose survival is dependent upon factors other than the severity of the liver disease and who may not manifest derangements in their MELD parameters. Such patients may be underserved by current MELD policies. This article reviews the development of MELD and the MELD-based liver allocation system and addresses issues relevant to whether this system may be improved.