A learning curve in using orphan liver allografts for transplantation.

Given the critical shortage of donor livers, marginal liver allografts have potential to increase donor supply. We investigate trends and long-term outcomes of liver transplant using national share allografts transplanted after rejection at the local and regional levels. We studied a cohort of 75 050 candidates listed in the Organ Procurement and Transplantation Network for liver transplantation between 2002 and 2016. We compared patients receiving national share and regional/local share allografts from 2002-2006, 2007-2011, and 2012-2016, performing multivariate Cox regression for graft survival. Recipient and center-level covariates that were not significant (P < .05) were removed. Graft survival of national share allografts improved over time. National share allografts had a 26% increased risk for graft failure in 2002-2006 but no impact on graft survival in 2007-2011 and 2012-2016. The cold ischemia time (CIT) of national share allografts decreased from 10.4 to 8.0 hours. We demonstrate that CIT had significant impact on graft survival using national share allografts (CIT <6 hours: hazard ratio 0.75 and CIT >12 hours: hazard ratio 1.25). Despite a trend toward sicker recipients and poorer quality allografts, graft survival outcomes using national share allografts have improved to benchmark levels. Reduction in cold ischemia time is a possible explanation.