Medical urgency for liver allocation is determined either by the MELD¹ or PELD² score, or by the assignment of a status (1A or 1B). The scores are intended to reflect the candidate’s disease severity, or the risk of 3-month mortality without access to liver transplant, and the scores and statuses are good discriminators of death for many candidates with chronic liver disease. However, for some the risk of death without access to liver transplant or the complications of the liver disease are not accurately predicted by the statuses or the MELD or PELD score. In these instances, the liver transplant program may request exceptions.

Hepatocellular carcinoma (HCC) is the most common diagnosis requiring a MELD or PELD score exception. The ability to request an exception for HCC has existed since the implementation of the MELD/PELD allocation system. In 2009, the OPTN Board of Directors adopted additional common diagnoses that often required MELD/PELD exceptions. All of these exceptions in policy are called standardized exceptions, and transplant programs can request a standardized exception for their candidates if the candidates meet the criteria contained within policy.³ For HCC, transplant programs can submit exception requests for candidates meeting standard criteria directly into UNet^SM. For the remaining diagnoses, transplant programs complete standard templates and submit them to the Chair of their respective Regional Review Board (RRB), who verifies that the candidate meets the policy criteria and approves them. If a standardized exception is approved, the exception scores are determined by policy and increase every 3 months until transplant as long as the candidates continue to meet criteria. Transplant programs are also permitted to request exceptions from the RRB for candidates who do not meet the criteria for the standardized MELD/PELD exceptions, but who may have complications of their liver disease not accounted for by the MELD score which increase their waitlist mortality.

Many OPTN/UNOS regions have adopted independent criteria used to request and approve non-standardized exceptions, commonly referred to as “regional agreements.” These regional agreements may contribute to regional differences in exception submission and award practices, even among regions with similar organ availability and candidate demographics.^4,5

The OPTN/UNOS Liver and Intestinal Organ Transplantation Committee (hereafter, the Committee) is pursuing the establishment of a National Liver Review Board (NLRB) to promote consistent, evidence-based review of exception requests and award of exception points. In support of this project, the Committee has developed guidance for specific clinical situations for use by the NLRB to evaluate common exceptional case requests for adult candidates, pediatric candidates, and candidates with hepatocellular carcinoma (HCC). However, the guidance contained in this proposal can be used by existing review boards upon adoption, independent of the implementation of the NLRB. This supplements existing national guidance and replaces the regional agreements. If adopted, review board members and transplant programs would consult this resource when considering submitting exception requests.

1 Model for End-Stage Liver Disease
2 Pediatric End-Stage Liver Disease
3 Policy 9.3.C: Specific MELD/PELD Exceptions, Organ Procurement and Transplantation Network Policies.
4 Argo, C.K., G.J. Stukenborg, T.M. Schmitt, et al. “Regional Variability in Symptom‐Based MELD Exceptions: A Response to Organ Shortage?” Am J Transplant, 11(2011): 2353-2361.
5 Rodriguez-Luna, H., H.E. Vargas, A. Moss, et al. “Regional variations in peer reviewed liver allocation under the MELD existing national guidance and replaces the regional agreements. If adopted, review board members and transplant programs would consult this resource when considering submitting exception requests.