MELD Exceptions and Rates of Waiting List Outcomes

Abstract

MELD-based allocation of deceased donor livers allows exceptions for patients whose score may not reflect their true mortality risk. We hypothesized that OPOs may differ in exception practices, use of exceptions may be increasing over time, and exception patients may be advantaged relative to other patients. We analyzed longitudinal MELD score, exception, and outcome in 88,981 adult liver candidates as reported to UNOS from2002–2010.Proportion of patients receiving an HCC exception was 0–21.4% at the OPO-level and 11.9–18.8% at the region-level; proportion receiving an exception for other conditions was 0.0%–13.1% (OPO-level) and 3.7%–9.5%% (region-level).HCC exceptions rose over time (10.5% in 2002 vs. 15.5% in 2008, HR=1.09 per year, p<0.001) as did other exceptions (7.0% in 2002 vs. 13.5% in 2008, HR=1.11, p<0.001).In the most recent era of HCC point assignment (since April 2005), both HCC and other exceptions were associated with decreased risk of waitlist mortality compared to non-exception patients with equivalent listing priority (multinomial logistic regression OR=0.47 for HCC, OR=0.43 for other, p<0.001) and increased odds of transplant (OR=1.65 for HCC, OR=1.33 for other, p<0.001).Policy advantages patients with MELD exceptions;differing rates of exceptions by OPO may create, or reflect, geographic inequity.

Model for End-stage Liver Disease

“…50 Even with this policy, the odds of a patient with HCC receiving the organ remains substantially higher compared to non-HCC patient. 51,52 On the other hand, about 29% of patients with HCC are dropped from the waiting list due to tumor progression suggesting consideration of other factors such as number of tumors, alphafetoprotein levels, tumor biology, and biological or calculated MELD score for transplanting HCC patients. 49,53 However, many of these factors are also associated with tumor recurrence after transplantation and a higher probability of drop out risk from the waiting list is directly correlated with a higher risk of recurrence of HCC after transplantation.…”

Treatment strategies for chronic hepatitis C prior to and following liver transplantation

“…Proponents of this view contend that post-LT treatment of HCV would alleviate this concern. We should be cognizant of the fact that up to 3000 potential liver transplant candidates are removed from the waitlist annually in the United Stateshalf develop contraindications for LT while the wait for a potential donor and the other half die from complications of end-stage liver disease [27] . Therefore, necessitating changes in allocation policies to reduce waitlist mortality [28] .…”

The emerging role of transport systems in liver function tests

“…However, certain diseases underlying liver failure necessitate exceptions from the MELD score (Massie et al, 2011). In such cases, novel markers of global liver function are needed and should be compared with the MELD score in individual…”