Does steatosis (fatty liver disease) prevent liver transplantation?

Does Steatosis Prevent Liver Transplantation?

Steatosis does not absolutely prevent liver transplantation, but the degree and type of steatosis critically determines graft suitability—mild macrovesicular steatosis (<30%) is safe for transplantation, moderate steatosis (30-60%) requires careful risk-benefit assessment, and severe macrovesicular steatosis (>60%) is associated with unacceptable risks and should generally be avoided. 1

Classification and Risk Stratification

The European Liver and Intestine Transplant Association (ELITA) 2025 guidelines provide the most current framework for evaluating steatotic liver grafts 1:

Mild Steatosis (<30% Macrovesicular)

• Can be safely transplanted with conventional cold storage when no additional risk factors are present 1
• Results in 5-year graft survival rates of 60% or more (comparable to non-steatotic grafts) when the Balance of Risk (BAR) score is ≤18 1
• Meta-analysis confirms no significant difference in primary nonfunction rates or early graft dysfunction compared to non-steatotic livers 2

Moderate Steatosis (30-60% Macrovesicular)

• May be considered for transplantation after careful balancing of risks and benefits 1
• Should be used with risk adjustment, ideally with BAR score ≤9 1
• Associated with significantly higher primary nonfunction rates (P=0.003) compared to non-steatotic grafts 2
• Can achieve acceptable outcomes in carefully selected donor-recipient combinations 1

Severe Steatosis (>60% Macrovesicular)

• Linked with unacceptable risks including graft failure, acute kidney injury, biliary complications, and mortality 1
• Meta-analysis demonstrates significantly elevated primary nonfunction rates (P<0.001) 2
• Generally contraindicated for transplantation with conventional cold storage 1

Type of Steatosis Matters

Microvesicular Steatosis

• Does not preclude the use of grafts 1
• Small fat droplets (<1mm) are not involved with poor graft function 1
• Can be used safely up to BAR score of 18 or less 1

Macrovesicular Steatosis

• Large droplets that occupy hepatocyte cytoplasm are the primary concern 1
• Volume of large droplet macrosteatosis is closely linked to transplantation suitability 1
• Associated with ischemia-reperfusion injury as the key mechanism of dysfunction 1

Clinical Outcomes and Evidence

Research demonstrates that steatotic livers can achieve good outcomes when properly selected:

• Graft and patient survival rates do not differ significantly between mild steatosis and non-steatotic groups 2
• Living donor liver transplantation studies show that moderate steatosis (20-50%) can be justified, though ischemia-reperfusion injury tends to be more severe 3
• Long-term organ survival (5-year rates of 68% for <30% steatosis vs 58% for ≥30% steatosis) shows no statistically significant difference after adjustment for confounders 4

Critical Pitfalls and Caveats

Interaction with Other Risk Factors

The complex interplay among different risk factors must be considered 1:

• Donor age, diabetes, and other comorbidities synergistically increase risk when combined with steatosis 1
• Recipient factors including HCV status historically affected outcomes (though less relevant in the direct-acting antiviral era) 1

Assessment Timing

• For living donors, macrovesicular steatosis >30% is generally considered a contraindication 5
• Short-term intensive treatment (diet, exercise, medications) can reduce steatosis from 30% to 12% in 2-8 weeks, potentially converting unsuitable donors to suitable candidates 6

Post-Transplant Considerations

• Steatosis may disappear after liver transplantation 1
• De novo or recurrent steatosis can develop post-transplant due to metabolic syndrome, immunosuppression, and other factors 7

Emerging Technologies

Normothermic machine perfusion devices may allow assessment and potential "defatting" of moderately and severely steatotic grafts prior to implantation, potentially expanding the donor pool 1. This represents an important future direction for utilizing grafts that would otherwise be unsuitable.

Practical Algorithm

1. Assess degree and type of steatosis via biopsy
2. If microvesicular or <30% macrovesicular with no additional risk factors → Proceed with transplantation 1
3. If 30-60% macrovesicular → Calculate BAR score and assess additional donor/recipient risk factors; proceed only if BAR ≤9 1
4. If >60% macrovesicular → Generally avoid unless machine perfusion assessment available 1
5. For living donors with >30% steatosis → Consider short-term intensive treatment to reduce steatosis before donation 6