Introduction: Patients with high MELD scores awaiting liver transplantation have a high risk of waiting list mortality and a short window of opportunity for rescue.  This issue is particularly acute in parts of the world with a relatively low deceased organ donor rate and sparse population, such as Australia and New Zealand.  Following a prospective study of liver transplant waiting list patients in Australia and New Zealand whose MELD score reached 35 during the period October 2013 to April 2015 and analysis of models of sharing deceased donor livers between units, based on data collected during the prospective study, it was agreed to commence a voluntary trial of sharing of livers for patients with a MELD score ≥ 35 (Share 35) if the unit local to the donor did not have a waiting list patient with a MELD score ≥ 25.  The aim of this study is to assess the impact of the trial on waiting list mortality.
Methods: Data regarding listing of Share 35 patients, including listing date, listing outcome, transplant date and transplant outcome, were maintained prospectively by the Australia and New Zealand Liver Transplant Registry.  The waiting list mortality rate of patients whose MELD score reached 35 between October 2013 and April 2015, prior to commencement of the Share 35 trial, “Share 35 candidates” was compared with that of patients listed as Share 35 patients during the period of the trial, from February 2016 to October 2017, “Share 35 listed”, using Chi square.  In order to assess the utility of liver transplantation, post-transplant survival of the two groups was compared using Kaplan-Meier graphs with log-rank.
Results: During the 21-month period of the trial, 24 patients were Share 35 listed, of whom 13 were transplanted with a shipped liver, eight were transplanted with a local donor liver and three died waiting.  The waiting list mortality rate of Share 35 listed patients (3 of 24, 13%) was significantly less than that of Share 35 candidates (13 of 27, 48%, P = 0.006).  Post-transplant survival was not significantly different between the groups (1-year survival for Share 35 listed patients, 77% vs Share 35 candidates, 86%, P = 0.420).
Discussion: Australia and New Zealand have had a successful program of sharing of organs between units for patients with acute liver failure for many years.  The Share 35 trial has demonstrated that this approach can be extended to patients with high MELD scores who have a similar risk of waiting list mortality.  Waiting list mortality was reduced by 74% without impacting post-transplantation survival.
Conclusion: Introduction of Share 35 to Australia and New Zealand has resulted in improved access to liver transplantation for a group of patients that previously were at high risk of waiting list death without adversely affecting utility.