Outcomes after Liver Transplantation with Steatotic Grafts: Redefining Acceptable Cutoffs for Steatotic Grafts

Abstract

Background: Graft macrosteatosis predisposes to a higher risk of ischemic reperfusion injury and has been associated with a wide range of adverse outcomes, especially shortly after LT, including an increased incidence of bile duct injury, higher rates of primary and early graft dysfunction, and worse graft survival We aim to explore the clinical outcomes of different graft steatosis cutoffs using the largest retrospective collection of steatotic grafts that underwent LT to date Methods: The data is obtained from the United Network for Organ Sharing-Standard Transplant Analysis and Research (UNOS-STAR) database We included all donors for recipients aged 18 and older who underwent LT between January 2004 to December 2018 in the study cohort We excluded living donors (n=3,537), HIV NAT+ donors (n=18), those donors with an unknown alcohol history (n=541), and donors with no biopsy data (n=60,359) leading to a final cohort of 29,161 evaluable donors. A high-risk steatotic (HRS) graft was defined as a donor graft with >20% macrosteatosis. HRS grafts was further classified as grafts with ≥20% to <30% (G1S grafts), ≥30% to <40% (G2S grafts), and ≥40% (G3S grafts). Reference grafts considered as low-risk steatotic grafts (LRS) was defined as grafts with ≤20% macrosteatosis. Results: Graft survival post-LT at shown in Figure 1 Recipients of LRS grafts had a graft survival of 92 9%, 90 5%, 87 1% at 3-months, 6-months, and 1-year Recipients of G1S grafts had a graft survival of 90 8%, 88 3%, 85 5% at 3-months, 6-months, and 1-year Recipients of G2S grafts had a graft survival of 90 4%, 88 0%, 84 4% at 3-months, 6-months, and 1-year Finally, recipients of G3S grafts had an estimated graft survival of 88 5%, 86 6%, 84 0% at 3-months, 6-months, and 1-year Using recipients of grafts with LRS as a reference, recipients of G1S (p=0 0006), G2S (p<0 0001), and G3S (p<0 0001) grafts had worse graft survival at 1-year Using recipients of G2S grafts as thereference, there was no difference in graft survival at 1-year compared to recipients of G1S or G3S grafts Conclusion: Recipients of grafts with ≥20 to <30% (G1S) had similar outcomes as recipients of grafts with ≥30% to <40% (G2S grafts), and ≥40% (G3S) grafts, 20% macrosteatosis may be the better cutoff mark for moderate steatosis compared to 30% Future studies should be conducted to evaluate the effectiveness of this practice on existing organ shortage issues.