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Higher thresholds for the utilization of steatotic allografts in liver transplantation: Analysis from a U.S. national
Justin A Steggerda1, Matthew B Bloom1,2, Mazen Noureddin3
1Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, United States of America.
Background:
Historically, liver allografts with >30% macrosteatosis (MaS) on donor biopsy have been associated with early allograft dysfunction and worse graft survival; however, successful outcomes have been reported in small cohorts. This study proposes an elevated MaS threshold for organ utilization without detriment to graft survival.
Methods:
The UNOS Standard Transplant Analysis and Research database was evaluated for transplants between 2006-2015. Graft survival up to 1-year was evaluated by Kaplan-Meier (KM) survival analyses, and by univariate and multivariable logistic regression analyses, including donor and recipient characteristics. Odds ratios (OR) with 95% confidence intervals (CI) for risk of graft loss are reported.
Results:
Thirty-day risk of graft loss was increased with MaS as low as 10-19% (OR [95% CI] 1.301 [1.055-1.605], p<0.0001) and peaked with MaS 50-59% (2.921 [1.672-5.103]). At 1-year, risk of graft loss remained elevated with MaS 40-49% (1.465 [1.002-2.142]) and MaS 50-59% (1.978 [1.281-3.056], p = 0.0224). Multivariable models were created for Lower and Higher MELD recipients and MaS cutoffs were established. In Lower MELD recipients, organs with ≥50% MaS had increased risk of graft loss at 30 days (2.451 [1.541-3.897], p = 0.0008) and 1-year post-transplant (1.720 [1.224-2.418], p = 0.0125). Higher MELD recipients had increased risk of graft loss at 30 days with allografts showing MaS ≥40% (4.204 [1.440-5.076], p = 0.0016). At 1-year the risk remained increased, but MaS was not significant predictor of graft loss.048 [1.131-3.710], p = 0.0616). In both MELD cohorts, organs with MaS levels below threshold had similar survival to those transplanted without a donor biopsy.
Conclusions:
In conjunction with recipient selection, organs with MaS up to 50% may be safely used without detriment to outcomes.
Insights
This study suggests that liver allografts with up to 50% macrosteatosis can be safely used in liver transplantation. Careful recipient selection is key to ensuring successful outcomes and improving organ utilization.
Area of Science:
- Transplantation immunology
- Hepatology
- Organ procurement and utilization
Background:
- Historically, liver allografts with >30% macrosteatosis (MaS) were deemed high-risk for early allograft dysfunction and reduced graft survival.
- Recent small cohorts have demonstrated successful outcomes with higher MaS, challenging the traditional threshold.
Purpose of the Study:
- To evaluate the safety and efficacy of utilizing liver allografts with an elevated macrosteatosis (MaS) threshold in liver transplantation.
- To establish new MaS utilization criteria based on recipient characteristics and graft survival.
Main Methods:
- Analysis of the UNOS Standard Transplant Analysis and Research database (2006-2015).
- Kaplan-Meier survival analyses and univariate/multivariable logistic regression to assess 1-year graft survival.
- Evaluation of donor and recipient characteristics, including MELD scores, to determine risk of graft loss.
Main Results:
- Graft loss risk increased with MaS as low as 10-19% at 30 days and remained elevated at 1-year for MaS 40-49% and 50-59%.
- In Lower MELD recipients, MaS ≥50% increased 30-day and 1-year graft loss risk.
- In Higher MELD recipients, MaS ≥40% increased 30-day graft loss risk, with no significant 1-year predictor.
Conclusions:
- Liver allografts with up to 50% macrosteatosis can be safely utilized in liver transplantation when combined with appropriate recipient selection.
- Established MaS thresholds vary by recipient MELD score, allowing for expanded organ utilization without compromising graft survival.
