Aggressive utilization of liver allografts: Improved outcomes over time

Background: Aggressive acceptance of liver allografts has driven utilization of marginal allografts. Our aim was to assess the impact of the aggressive phenotype on transplant center outcomes over time.

Methods: We used a cohort of 148 361 candidates from the Organ Procurement and Transplantation Network for liver transplantation between 2002 and 2016 in 134 centers. Using the Discard Risk Index, we designated high probability discard allografts by the top 10th percentile for likelihood of discard. Aggressive phenotype was defined by usage of high probability discard (HPD) allografts (top 10th percentile). Our analysis of survival on waitlist and graft survival after transplantation included a comprehensive list of center level covariates across three equal time periods (2002-2006, 2007-2011, and 2012-2016).

Results: After adjusting for recipient and center-level factors, aggressive centers had improving graft survival over time. Aggressive vs non-aggressive centers: 2002-2006 HR 1.12 (1.05-1.19), 2007-2011 HR 1.13 (1.05-1.22), 2012-2016 HR 0.99 (0.89-1.10). Aggressive centers had improved waitlist survival compared with non-aggressive centers after adjusting for allograft disparity.

Conclusions: Aggressive phenotype had a positive impact on waitlist survival, and graft survival in aggressive centers have improved to benchmark levels over time. These findings serve as justification for aggressive utilization of allografts.