Overcoming the hurdles of steatotic grafts in liver transplantation: Insights into survival and prognostic factors

Abstract

Background: With increasing metabolic dysfunction associated steatotic liver disease (MASLD), the use of steatotic grafts in liver transplantation (LT) and their impact on postoperative graft survival (GS) needs further exploration. Method: Analyzing adult LT recipient data (2002-2022) from the United Network for Organ Sharing database, outcomes of LT using steatotic (≥30% macrosteatosis) and non-steatotic donor livers, donors after circulatory death (DCD), and standard-risk older donors (age 45-50) were compared. GS predictors were evaluated using Kaplan-Meier and Cox regression analyses. Results: Of the 35,345 LT donors, 8.9% (3,155) were fatty livers. Initial 30-day postoperative period revealed significant challenges with fatty livers, demonstrating inferior GS. However, the GS discrepancy between fatty and non-fatty livers subsided over time (p=0.10 at 5 y). Long-term GS outcomes showed comparable or even superior results in fatty livers relative to non-steatotic livers, conditional on surviving the initial 90 postoperative days (p=0.90 at 1 y) or 1 year (p=0.03 at 5 y). In the multivariable Cox regression analysis, high body surface area (BSA) ratio (≥1.1) (hazard ratio [HR] 1.42, p=0.02), calculated as donor BSA divided by recipient BSA, long cold ischemic time (≥6.5 hours) (HR 1.72, p<0.01), and recipient medical condition (ICU hospitalization) (HR 2.53, p<0.01) emerged as significant adverse prognostic factors. Young (<40 y) fatty donors showed a high BSA ratio, diabetes, and ICU hospitalization as significant indicators of worse prognosis (p<0.01). Conclusion: Our study emphasizes the initial postoperative 30-day survival challenge in LT using fatty livers. However, with careful donor-recipient matching, e.g. avoiding use of steatotic donors with long cold ischemic time and high BSA ratios for recipients in the ICU, it is possible to enhance immediate GS, and in a longer time, outcomes comparable to those using non-fatty livers, DCD livers, or standard-risk older donors, can be anticipated. These novel insights into decision-making criteria for steatotic liver use provide invaluable guidance for clinicians.