MELD-Based Liver Allocation: Who Is Underserved?

ABSTRACT

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.

KEYWORDS

MELD - liver transplantation - allocation - exceptions - public policy

REFERENCES

• 1 Malinchoc M, Kamath P S, Gordon F D, Peine C J, Rank J, Borg P C. A model to predict poor survival in patients undergoing transjugular intrahepatic portosystemic shunts.  Hepatology. 2000;  31 864-871
• 2 Kamath P, Wiesner R, Malinchoc M, Kremers W, Therneau T, Kosberg C. A model to predict survival in patients with end-stage liver disease.  Hepatology. 2001;  33 464-470
• 3 Freeman Jr R B, Edwards E B. Liver transplant waiting time does not correlate with waiting list mortality: implications for liver allocation policy.  Liver Transpl. 2000;  6 543-552
• 4 Institute of Medicine .Analysis of waiting times.  In: Committee on Organ Transplantation: Assessing Current Policies and the Potential Impact of the DHHS Final Rule. Washington, DC; National Academy Press 1999: 57
• 5 Organ Procurement and Transplantation Network-HRSA . Final rule with comment period.  Fed Regist. 1998;  63 16296-16338
• 6 Christensen E, Schlichting P, Fauerholdt L et al.. Prognostic value of Child-Turcotte criteria in medically treated cirrhosis.  Hepatology. 1984;  4 430-435
• 7 Wiesner R, Edwards E, Freeman R et al.. Model for end-stage liver disease (MELD) and allocation of donor livers.  Gastroenterology. 2003;  124 91-96
• 8 UNOS .Organ Distribution: Allocation of Livers Policy 3.6 http://Available at: www.unos.org Accessed March 4, 2006
• 9 Kremers W K, Van I M, Kim W R et al.. MELD score as a predictor of pretransplant and posttransplant survival in OPTN/UNOS status 1 patients.  Hepatology. 2004;  39 764-769
• 10 Freeman R B, Wiesner R H, Edwards E, Harper A, Merion R, Wolfe R. Results of the first year of the new liver allocation plan.  Liver Transpl. 2004;  10 7-15
• 11 2004 OPTN/SRTR Annual Report. HHC/HRSA/HSB/DOT; UNOS; URREA. 
• 12 Merion R M, Schaubel D E, Dykstra D M, Freeman R B, Port F K, Wolfe R A. The survival benefit of liver transplantation.  Am J Transplant. 2005;  5 307-313
• 13 Merion R M, Wolfe R A, Dykstra D M, Leichtman A B, Gillespie B, Held P J. Longitudinal assessment of mortality risk among candidates for liver transplantation.  Liver Transpl. 2003;  9 12-18
• 14 Bambha K, Kim W R, Kremers W K et al.. Predicting survival among patients listed for liver transplantation: an assessment of serial MELD measurements.  Am J Transplant. 2004;  4 1798-1804
• 15 Report of the OPTN/UNOS Liver and Intestinal Organ Transplantation Committee to the Board of Directors .June 26-27, 2003
• 16 Trotter J F, Osgood M J. MELD scores of liver transplant recipients according to size of waiting list: impact of organ allocation and patient outcomes.  JAMA. 2004;  291 1871-1874
• 17 Washburn K, Harper A, Klintmalm G, Goss J, Halff G. Regional sharing for adult status 1 candidates: reduction in waitlist mortality.  Liver Transpl. 2006;  12 470-474
• 18 Humar A, Khwaja K, Glessing B et al.. Regionwide sharing for status 1 liver patients: beneficial impact on waiting time and pre- and posttransplant survival.  Liver Transpl. 2004;  10 661-665
• 19 Busuttil R W, Farmer D G, Yersiz H et al.. Analysis of long-term outcomes of 3200 liver transplantations over two decades: a single-center experience.  Ann Surg. 2005;  241 905-916
• 20 2005 OPTN/SRTR Annual Report. HHC/HRSA/HSB/DOT; UNOS; URREA. 
• 21 Rodriguez-Luna H, Vargas H E, Moss A, Reddy K S, Freeman R B, Mulligan D. Regional variations in peer reviewed liver allocation under the MELD system.  Am J Transplant. 2005;  5 2244-2247
• 22 UNOS Liver and Intestine Committee .Proposal for Standard Guidelines for MELD/PELD Exceptions. http://Available at: www.unos.org Accessed January 3, 2006
• 23 Freeman Jr R B, Wiesner R H, Harper A et al.. The new liver allocation system: moving toward evidence-based transplantation policy.  Liver Transpl. 2002;  8 851-858
• 24 Wiesner R H, McDiarmid S V, Kamath P S et al.. MELD and PELD: application of survival models to liver allocation.  Liver Transpl. 2001;  7 567-580
• 25 Heuman D M, Abou-Assi S G, Habib A et al.. Persistent ascites and low serum sodium identify patients with cirrhosis and low MELD scores who are at high risk for early death.  Hepatology. 2004;  40 802-810
• 26 Heuman D M, Mihas A. Utility of the MELD score for assessing 3-month survival in patients with liver cirrhosis: one more positive answer.  Gastroenterology. 2003;  125 992-993 author reply 994-995
• 27 Ripoll C, Banares R, Rincon D et al.. Influence of hepatic venous pressure gradient on the prediction of survival of patients with cirrhosis in the MELD era.  Hepatology. 2005;  42 793-801
• 28 Schrier R W, Gurevich A K, Cadnapaphornchai M A. Pathogenesis and management of sodium and water retention in cardiac failure and cirrhosis.  Semin Nephrol. 2001;  21 157-172
• 29 Porcel A, Diaz F, Rendon P, Macias M, Martin-Herrera L, Giron-Gonzalez J A. Dilutional hyponatremia in patients with cirrhosis and ascites.  Arch Intern Med. 2002;  162 323-328
• 30 Fernandez-Esparrach G, Sanchez-Fueyo A, Gines P et al.. A prognostic model for predicting survival in cirrhosis with ascites.  J Hepatol. 2001;  34 46-52
• 31 Biggins S W, Rodriguez H J, Bacchetti P, Bass N M, Roberts J P, Terrault N A. Serum sodium predicts mortality in patients listed for liver transplantation.  Hepatology. 2005;  41 32-39
• 32 Ruf A E, Kremers W K, Chavez L L, Descalzi V I, Podesta L G, Villamil F G. Addition of serum sodium into the MELD score predicts waiting list mortality better than MELD alone.  Liver Transpl. 2005;  11 336-343
• 33 Biggins S, Kim W, Terrault N et al.. Evidence-based incorporation of serum sodium concentration into MELD.  Gastroenterology. 2006;  130 1652-1660
• 34 Adler M, Verset D, Bouhdid H et al.. Prognostic evaluation of patients with parenchymal cirrhosis: proposal of a new simple score.  J Hepatol. 1997;  26 642-649
• 35 Said A, Williams J, Holden J et al.. Model for end stage liver disease score predicts mortality across a broad spectrum of liver disease.  J Hepatol. 2004;  40 897-903
• 36 Bajaj J S, Saeian K. MELD score does not discriminate against patients with hepatic encephalopathy.  Dig Dis Sci. 2005;  50 753-756
• 37 D'Amico G, De Franchis R. Upper digestive bleeding in cirrhosis: post-therapeutic outcome and prognostic indicators.  Hepatology. 2003;  38 599-612
• 38 Chalasani N, Kahi C, Francois F et al.. Model for end-stage liver disease (MELD) for predicting mortality in patients with acute variceal bleeding.  Hepatology. 2002;  35 1282-1284
• 39 Brandsaeter B, Broome U, Isoniemi H et al.. Liver transplantation for primary sclerosing cholangitis in the Nordic countries: outcome after acceptance to the waiting list.  Liver Transpl. 2003;  9 961-969
• 40 Heimbach J K, Haddock M G, Alberts S R et al.. Transplantation for hilar cholangiocarcinoma.  Liver Transpl. 2004;  10 S65-S68
• 41 Stock P G. Rapid deterioration of HIV co-infected patients waiting for liver transplantation is not predicted by MELD.  Liver Transpl. 2005;  11 1315-1317
• 42 Roland M E, Stock P G. Review of solid-organ transplantation in HIV-infected patients.  Transplantation. 2003;  75 425-429
• 43 Ragni M V, Belle S H, Im K et al.. Liver transplantation in HIV-seropositive individuals.  Ann Intern Med. 2006;  144 223 author reply 223-224
• 44 Kayali Z, Ranguelov R, Mitros F et al.. Hemosiderosis is associated with accelerated decompensation and decreased survival in patients with cirrhosis.  Liver Int. 2005;  25 41-48
• 45 Dahm F, Georgiev P, Clavien P A. Small-for-size syndrome after partial liver transplantation: definition, mechanisms of disease and clinical implications.  Am J Transplant. 2005;  5 2605-2610