Ann Kim¹, Koji Hashimoto², Joan Alster³, Bijan Eghtesad², Charles Miller², John Fung², Cristiano Quintini²

¹School of Medicine, Case Western Reserve University, Cleveland, OH, United States; ²Departments of Hepato-Pancreato-Biliary and Transplant Surgery, Cleveland Clinic, Cleveland, OH, United States; ³Department of Biostatistics and Epidemiology, Cleveland Clinic, Cleveland, OH, United States

Introduction: Combined liver and intestinal transplant recipients have historically had the highest waiting list mortality rate. Their clinical condition along with organ scarcity accounts for the majority of these deaths. Since the introduction of the Model for End-Stage Liver Disease (MELD) score, the United Network for Organ Sharing (UNOS) implemented several amendments to their liver allocation policies in an effort to improve access to available organs.  These changes included adjustment of the MELD score for combined liver-intestine candidates as well as revisions to the UNOS liver allocation algorithm. The purpose of this study was 1) to determine the efficacy of these policy changes as a means to reduce waiting list mortality rate in patients awaiting a “liver-containing” graft and 2) the impact of recipient weight on waiting list dynamics.

Materials and Methods: The study is a retrospective analysis of 143,283 adult candidates listed in the UNOS database for either liver alone or combined liver-intestine transplants in the U.S. from 1993 to 2008. Mortality rates were compared and the impact of recipient weight (cut off value of 50 kg) assessed.

Results: Since 1993, the waiting list mortality rates for liver-intestine candidates followed a downward trend but remained significantly higher than that seen in liver-only candidates (see figure).  Between 2006 and 2008, the mortality rate was 499 person years (pyrs) for patients awaiting a liver-intestine graft versus 149 pyrs observed in patients awaiting liver alone (p=<0.001).  Weight was also found to have a greater negative impact on adults of <50 kg listed for combined graft compared to liver alone (648 pyrs versus 163 pyrs). 

Conclusion: The presence of persistently high mortality rates among adult patients awaiting a combined liver-intestine graft indicates the need to reassess the liver allocation policy. Furthermore, weight should be factored into the allocation algorithm for combined grafts.