Hypothermic Machine Preservation and Transplantation of “Orphan” Extended Criteria Donor Livers.

Abstract

Introduction: Hypothermic machine perfusion (HMP) remains investigational in clinical liver transplantation despite widespread utilization in renal transplantation with improved results. Our group has reported the only clinical liver HMP series worldwide with promising results. The aim of this study was to investigate liver HMP in Extended Criteria Donor (ECD) Livers turned down by all other centers in the originating UNOS region (“orphan livers”). Methods: All included HMP livers were “orphan livers” and met at least one of the following ECD Criteria 1) Donor age>65; 2) >25% Macrosteatosis; 3) HCV+ and at least 15% macrosteatosis; 4) donor ischemic injury with AST or ALT>1,000 at time of offer. Thirty one livers were included in the study and underwent HMP for 3-7hrs using centrifugal perfusion with Vasosol® solution and were allografts for solitary, primary transplants in patients with a MELD score<35. These cases were matched to historical Cold Storage (CS) controls based on donor and recipient age, cold ischemic time, donor risk index and MELD score. Results: There were no technical or mechanical failures of HMP. Perfusate electrolytes and parameters were stable in almost all cases. Perfusate levels of AST correlated with the recipient’s peak serum AST on linear regression. There were 2 cases of Primary nonfunction in the CS group and one in the HMP group. Early allograft dysfunction (EAD) rates were 30% in CS controls vs 19% in the HMP group. Time to normalization of serum markers of liver and renal function were lower in the HMP group with serum creatinine on POD 5 being significantly lower in the HMP group. At 12 months, there were five deaths in the HMP group and 6 in the CS group (p=NS). Biliary complications were significantly lower in the HMP group compared to the CS group (4 vs 13, p=0.016) with almost twice as many ERCPs required in the CS group. Mean hospital stay was significantly shorter in the HMP group (13.65±10.9 days vs. 20.14±11.12 days in the CS group, p=0.012). HMP of orphan extended criteria donor livers provided safe and reliable preservation with significantly less biliary complications and overall length of stay in HMP patients. Further multicenter experience with HMP is necessary to further elucidate clinical benefits of HMP in Liver Transplantation.