Identifying independent risk factors for graft loss after primary liver transplantation.

Abstract

The aim of the study is the identification of independent risk factors for re-transplantation after primary liver transplantation beyond the occurrence of hepatic artery thrombosis. Eight hundred thirty-four adult patients undergoing primary liver transplantation were analyzed. A propensity score was developed using multivariable binary logistic regression with hepatic artery thrombosis as the dependent variable. The logit link function of the propensity score was included into multivariable Cox regression analysis for graft survival to adjust the study population. Graft loss was observed in 134 patients (16.1%). Independent significant risk factors for graft loss were recipient platelet count (p=0.040; HR: 1.002; 95%-CI: 1.000-1.003), preoperative portal vein thrombosis (p=0.032; HR: 1.797; 95%-CI: 1.054-2.925), donor age (p<0.001; HR: 1.026; 95%-CI: 1.012-1.040), percentage of macrovesicular steatosis of the graft (p=0.011; HR: 1.037; 95%-CI: 1.009-1.061), early complications leading to revision surgery (p<0.001; HR: 2.734; 95%-CI: 1.897-3.956), duration of the transplant procedure (p<0.001; HR: 1.005; 95%-CI: 1.003-1.007) as well as transplantation of a split liver graft (p=0.003; HR: 2.637; 95%-CI: 1.420-4.728). The logit of the propensity score did not reach statistical significance in the final multivariable Cox regression model (p=0.111) indicating good adjustment for the occurrence of hepatic artery thrombosis. Liver transplant programs might benefit from regular donor organ biopsies to assess the amount of macrovesicular steatosis. An elevated recipient platelet count can promote reperfusion injury leading to graft loss. A liver graft from an elderly donor should not be split or be transplanted in a recipient with detected portal vein thrombosis.