Effect of centre volume and high donor risk index on liver allograft survival

BackgroundA growth in the utilization of high-risk allografts is reflective of a critical national shortage and the increasing waiting list mortality. Using risk-adjusted models, the aim of the present study was to determine whether a volume–outcome relationship existed among liver transplants at high risk for allograft failure.MethodsFrom 2002 to 2008, the Scientific Registry of Transplant Recipients (SRTR) database for all adult deceased donor liver transplants (n= 31 587) was queried. Transplant centres (n= 102) were categorized by volume into tertiles: low (LVC; 31 cases/year), medium (MVC: 64 cases/year) and high (HVC: 102 cases/year). Donor risk comparison groups were stratified by quartiles of the Donor Risk Index (DRI) spectrum: low risk (DRI ≤ 1.63), moderate risk (1.64 > DRI > 1.90), high risk (1.91 > DRI > 2.26) and very high risk (DRI ≥ 2.27).ResultsHVC more frequently used higher-risk livers (median DRI: LVC: 1.82, MVC: 1.90, HVC: 1.97; P < 0.0001) and achieved better risk adjusted allograft survival outcomes compared with LVC (HR: 0.90, 95%CI: 0.85–0.95). For high and very high risk groups, transplantation at a HVC did contribute to improved graft survival [high risk: hazard ratio (HR): 0.85, 95% confidence interval (CI): 0.76–0.96; Very High Risk: HR: 0.88, 95%CI: 0.78–0.99].ConclusionWhile DRI remains an important aspect of allograft survival prediction models, liver transplantation at a HVC appears to result in improved allograft survival with high and very high risk DRI organs compared with LVC.