Clavien, P A

Background. The adoption of technical variant grafts has expanded the donor pool for pediatric liver transplantation, but it also poses a risk of portal vein thrombosis (PVT). This study evaluated risk and prognostic factors of PVT in children undergoing liver transplantation with technical variant grafts. Methods. A total of 3137 pediatric patients from 19 centers were included: 470 received split/reduced deceased donor grafts and 2667 received living donor grafts. Multivariable logistic regression was used to identify risk factors, whereas time-dependent Cox models were used to assess the impact on survival. Results. PVT occurred in 102 patients (3.3%) and was associated with increased mortality (adjusted hazard ratio, 2.86; 95% confidence interval [CI], 1.13-7.25; P = 0.027) and graft loss (adjusted hazard ratio, 9.97; 95% CI, 4.90-20.3; P < 0.001). Risk factors included younger age, lower weight, higher Pediatric End-Stage Liver Disease score, longer cold ischemia and operation times, higher graft-to-recipient weight ratio, increased red blood cell transfusions, and biliary atresia. After adjusting for center, lower weight (odds ratio, 0.84 per kg; 95% CI, 0.71-1.00; P = 0.047) and biliary atresia (odds ratio, 2.34; 95% CI, 1.10-5.00; P = 0.027) remained predictors. Five-year patient (88.4% versus 93.1%) and graft survival (82.7% versus 96.3%) were significantly inferior in patients with PVT. Conclusions. Low-weight children with biliary atresia constituted a high-risk group, highlighting the necessity for early detection and management.

Abstract Background Machine perfusion represents the most significant breakthrough in liver transplantation (LT) since the discovery of cyclosporin. Yet, the optimal perfusion strategy remains unsettled. Randomized trials demonstrate that hypothermic oxygenated perfusion (HOPE) improves graft survival and function and reduces ischemic cholangiopathy, whereas normothermic machine perfusion (NMP) decreases post-transplant injury. Real-world comparisons are lacking and challenging due to heterogeneity in donor-recipient risk profiles and regional differences. Aims To compare real-world outcomes of HOPE and NMP in LT. Methods We analyzed consecutive NMP-preserved LTs from seven North American centers between 2021 and 2024. We compared NMP to the European HOPE-REAL cohort, comprising HOPE-treated LTs from 22 centers between 2012 and 2021. Analyses were stratifyied by graft type and risk category and adjusted for donor age, donor risk index, and balance of risk score using entropy balancing. Results A total of 470 NMP and 1202 HOPE-treated grafts were analyzed, revealing major differences in risk profiles (Figure 1). In NMP, death-censored graft survivals at 1, 2, and 3 years were &gt;95% in donation after brain death (DBD) and &gt;94% in donation after circulatory death (DCD) grafts. Comparable outcomes were observed in the HOPE cohort with &gt;93%, in DBD, and &gt;87% in DCD after up to 3 years, despite significantly higher donor age and longer functional warm ischemia in the HOPE DCD cohort (Figure 2). After risk adjustment, death-censored graft survival remained similar between both modalities (Table 1). Non-anastomotic biliary stricture rates after DCD-LT were comparable (8.5% vs. 12.4%), independent of whether continuous or end-ischemic NMP was performed. Conclusion This first transatlantic real-world report demonstrates excellent outcomes with both NMP and HOPE despite higher graft risk in Europe. Machine perfusion is the new standard of care in LT, while further understanding is needed regarding the distinct benefits of each modality across risk profiles.Figure 1.Graft risk in NMP and HOPE stratified by graft type. Benchmark case was defined as primary transplant with MELD &lt;20 and BAR score &lt;9, extended criteria as either BMI &gt;30kg/m2, donor age &gt;65 years, CIT &gt;12h. DCD grafts were categorized as definedFor image description, please refer to the figure legend and surrounding text. Figure 2.Death-censored graft survival in liver transplantation following NMP and HOPE stratified by graft type. Abbreviations: NMP (Normothermic Machine Perfusion), HOPE (Hypothermic Oxygenated Perfusion), DBD (Donation after Brain Death), DCD (Donation after circulatory death)For image description, please refer to the figure legend and surrounding text. Table 1.Risk-adjusted comparison of death-censored graft survival between NMP and HOPE.For image description, please refer to the figure legend and surrounding text.