Effects of Allocating Livers for Transplantation Based on Model for End-Stage Liver Disease-Sodium Scores on Patient Outcomes

Gastroenterology. 2018 Nov;155(5):1451-1462.e3. doi: 10.1053/j.gastro.2018.07.025. Epub 2018 Jul 26.


Background & aims: The Model for End-stage Liver Disease and Sodium (MELD-Na) score was introduced for liver allocation in January 2016. We evaluated the effects of liver allocation, based on MELD-Na score, on waitlist and post-transplantation outcomes.

Methods: We examined 2 patient groups from the United Network for Organ Sharing registry; the MELD-period group was composed of patients who were registered as transplant candidates from June 18, 2013 through January 10, 2016 (n = 18,850) and the MELD-Na period group was composed of patients who were registered from January 11, 2016 through September 30, 2017 (n = 14,512). We compared waitlist and post-transplantation outcomes and association with serum sodium concentrations between groups.

Results: Mortality within 90 days on the liver waitlist decreased (hazard ratio [HR] 0.738, P < .001) and transplantation probability increased significantly (HR 1.217, P < .001) in the MELD-Na period. Although mild, moderate, and severe hyponatremia (130-134, 125-129, and <125 mmol/L) were independent risk factors for waitlist mortality in the MELD period (HR 1.354, 1.762, and 2.656; P < .001, P < .001, and P < .001, respectively) compared with the reference standard (135-145 mmol/L), these adverse outcomes were decreased in the MELD-Na period (HR 1.092, 1.271 and 1.374; P = .27, P = .018, and P = .037, respectively). The adjusted survival benefit of transplant recipients vs patients placed on the waitlist in the same score categories was definitive for patients with MELD-Na scores of 21-23 in the MELD-Na era (HR 0.336, P < .001) compared with MELD scores of 15-17 in the MELD era (HR 0.365, P < .001).

Conclusions: Liver allocation based on MELD-Na score successfully improved waitlist outcomes and provided significant benefit to hyponatremic patients. Given the discrepancy in transplantation survival benefit, the current rules for liver allocation might require revision.

Keywords: Hyponatremia; Survival Benefit; United Network for Organ Sharing; Waitlist Mortality.

MeSH terms

  • End Stage Liver Disease / surgery*
  • Female
  • Hepatitis C / complications
  • Humans
  • Liver Transplantation* / mortality
  • Male
  • Middle Aged
  • Sodium / blood*
  • Tissue and Organ Procurement*
  • Waiting Lists


  • Sodium