The MELD score in patients awaiting liver transplant: Strengths and weaknesses

Abstract

Adoption of the Model for End-stage Liver Disease (MELD) to select and prioritize patients for liver transplantation represented a turning point in organ allocation. Prioritization of transplant recipients switched from time accrued on the waiting list to the principle of "sickest first". The MELD score incorporates three simple laboratory parameters (serum creatinine and bilirubin, and INR for prothrombin time) and stratifies patients according to their disease severity in an objective and continuous ranking scale. Concordance statistics have demonstrated its high accuracy in stratifying patients according to their risk of dying in the short-term (three months). Further validations of MELD as a predictor of survival at various temporal end-points have been obtained in independent patient cohorts with a broad spectrum of chronic liver disease. The MELD-based liver graft allocation policy has led to a reduction in waitlist new registrations and mortality, shorter waiting times, and an increase in transplants, without altering overall graft and patient survival rates after transplantation. MELD limitations are related either to the inter-laboratory variability of the parameters included in the score, or to the inability of the formula to predict mortality accurately in specific settings. For some conditions, such as hepatocellular carcinoma, widely accepted MELD corrections have been devised. For others, such as persistent ascites and hyponatremia, attempts to improve MELD's predicting power are currently underway, but await definite validation.

Barriers to Transplantation in Adults with Inborn Errors of Metabolism

“…A registry which collects data on adults with IEM who have undergone transplantation might be one strategy by which evidence could be collected on the outcomes of transplantation in these patients. (Bernardi et al 2011). To address this problem, a working group developed a short list of genetic conditions (including familial hyperoxaluria and familial amyloid polyneuropathy) to which exceptions to the MELD system are accepted (Freeman et al 2006) and "unusual metabolic diseases" are included, although few are named as exceptions.…”

Pre-transplant Predictors for 3-Month Mortality after Living Donor Liver Transplantation

“…The model for end-stage liver disease (MELD) score was initially described to predict patient survival rates and complications after transjugular intrahepatic portosystemic shunt procedures (5). The MELD score was adopted by the United Network for Organ Sharing as the standard priority rule for determining who should receive liver transplants (6).…”

Hepatorenal syndrome, MELD score and liver transplantation: An evolving issue with relevant implications for clinical practice

“…It has proved to be a reliable tool for prioritizing these patients in the LT waiting list and it has contributed to optimize the allocation of grafts according to a ''sickest first'' policy [19]. Nevertheless, there are conditions that are not properly considered by the MELD score, either because they are not sufficiently ''perceived'' and weighted by the variables included in the score, or because their short-term risk is progression beyond the limit of transplant suitability, rather than death [20][21][22]. HRS can be included in the first category of such conditions.…”

“…Thus, a patient with HRS should receive a priority to LT that is not based only on the MELD score, but that also takes into account HRS, as it is the poorest predictor of 3-month survival among the different causes of renal failure in cirrhosis. This is not provided by the policy of ''exceptions to the MELD score'' that are currently used in several Western countries such as Italy [20], France [21], and the US [22]. According to what has been recently suggested as essential to justify any proposal for an ''exception to MELD'', here we are dealing with a problem of mortality and not only of quality of life.…”