Difficult liver transplantation: Definition, risk factors and outcome.

Background: Although liver transplantation (LT) is highly complicated, its surgical difficulty was to date not defined. A point-based system, considering cold ischemia, blood transfused, and surgery time, showed promising results in short-term outcomes.

Aims: We aimed to validate this model in the Eurotransplant region and to combine donor and recipient data to highlight high-risk candidates.

Methods: We analyzed 778 primary LT patients, transplanted between January 2010 and January 2023. After applying the original score, instead of cold ischemia, hepatectomy time was calculated. A LT was considered difficult (Diff-LT), if all values were above the median of the whole population. Mortality was assessed with the Kaplan-Meier method. Predictors of Diff-LT were identified via multivariable analysis. Correlation with survival was tested via Cox regression.

Results: Diff-LT was associated with inferior survival in both score systems. MELD score, recipient BMI, and previous abdominal surgery were mostly risk factors of Diff-LT. Whereas, Diff-LT, recipient age, early allograft dysfunction, and portal vein thrombosis (PVT) were identified as predictors of mortality.

Conclusion: Diff-LT occurs frequently and results in poorer outcomes. Older and obese recipients with high MELD scores and PVT are at higher risk to undergo a Diff-LT. Identification of these patients, adjusting their risk factors and optimizing donor-recipient matching may improve future results.