Jeroen de Jonge

Introduction: The use of donor kidneys from older donation after circulatory death (DCD) donors is limited due to increased susceptibility to ischemia–reperfusion injury, resulting in delayed graft function (DGF) and graft loss. While hypothermic machine perfusion (HMP) with oxygen (HMPO ₂ ) offers some benefit, clinical outcomes remain suboptimal. Emerging normothermic preservation techniques, such as abdominal normothermic regional perfusion (aNRP) and normothermic machine perfusion (NMP), may enhance graft viability in high‐risk transplants. This study compares post‐transplant outcomes of aNRP versus NMP in DCD donors over 50 years of age. Materials and Methods: Data were collected from two clinical trials (NMP group) and a national registry (aNRP group). The primary outcome was the incidence of DGF. Secondary outcomes included primary non‐function (PNF), acute rejection, death‐censored graft and patient survival, and longitudinal kidney function (eGFR) until three years after transplantation. Results: The outcomes of 85 kidneys that underwent aNRP were compared to 29 kidneys that underwent NMP. No significant difference was observed in the incidence of DGF (aNRP: 46% vs. NMP: 52%, p = 0.82), PNF (aNRP: 8% vs. NMP: 7%, p = 0.87) or acute rejection (25% vs. 31%, p = 0.67). Death‐censored graft and patient survival was similar in the aNRP and NMP group. At three years post‐transplant, median eGFR was 38 (±2.1) mL/min/1.73 m ² in the aNRP group and 33 (±3.8) mL/min/1.73 m ² in the NMP group. Conclusion: The findings of this study demonstrate that both aNRP and NMP provide similar graft outcomes in older DCD kidney transplantation, potentially increasing the acceptance of high‐risk donor kidneys by transplant centers. The interpretation of the results of this study is limited by its non‐randomized design and small sample size.

Introduction: Donation after circulatory death (DCD) graft use has become a standard practice globally to increase access to liver transplantation (LT). Machine preservation strategies have been widely adopted to improve graft quality, mitigate ischemia-reperfusion injury, expand organ utilization and enable organ viability assessment. However, the various approaches to MP have never been directly compared, particularly in the DCD cohort which might experience the greatest benefit. Methods: All cases of adult DCD-LT 2014-2024 preserved MP were collected from centers in Italy, The Netherlands, Switzerland, UK, and USA. DCD grafts preserved with cold storage (SCS) alone from previously established DCD-benchmarking cohorts served as comparators. Core Outcome Sets methodology was employed for standardized outcome analysis, comparing the impact of MP technologies in DCD grafts within established “benchmark” criteria to those with extended risk factors outside benchmarks. Results: Data were collected for 1538 perfused DCD-LT from >30 transplant centers; 995 (65%) were outside-benchmark criteria. Nearly half received NRP alone or combined with ex-situ perfusion (49%). Inside benchmark, nonanastomotic biliary strictures (NAS) were equally common in upfront NMP (14%) and back-to-base (B-t-B) NMP (14%). NRP (1%) and NRP+HOPE (2%) were protective ( P P 2 =0.201, Marginal=0.187). Similar trends were observed regarding actuarial 1-year GS. Conclusions and Relevance: Machine preservation strategies were associated with differences in outcomes in DCD LT and with lower observed NAS incidence and favorable adjusted survival estimates in DCD LT. NMP-based preservation was not associated with statistically significant reductions in NAS compared with benchmark SCS cohorts.

Background and Objectives: Normothermic regional perfusion (NRP) is an effective technique to improve recipient outcomes. However, no valid methods for determining liver viability exist. Identifying relevant biological markers with clinical correlation to liver viability and recipient clinical outcomes is imperative to improve decision-making. Materials and Methods: Fifty-four donors undergoing NRP and their recipients were included. FMN was measured at the start, 1 h, and end of NRP. Lactate was measured at the start, 30, 60, and 90 min of NRP. Primary outcomes were early allograft function using the early allograft dysfunction (EAD) criteria and the model for early allograft function (MEAF). Secondary outcomes included the association with donor warm ischemia time (DWIT), stratified by 30 min. Spearman’s rho assessed correlations. Results: Forty (74%) livers were transplanted, with 5 (12.5%) recipients developing EAD and the mean MEAF score was 3.13 (1.49). FMN at all time points was significantly greater in the EAD group compared to the non-EAD group and was significantly correlated with the MEAF score (Peak FMN: rho = 0.507, p = 0.001). FMN during perfusion did not differ between DWIT < and ≥30 min. Lactate levels were similar across all groups and did not discriminate for adverse allograft outcomes. However, lactate levels during perfusion were higher in the DWIT ≥ 30 min group. Conclusions: These findings suggest that during NRP, elevated FMN, but not lactate, is associated with early allograft function.

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Background.: With growing transplant waiting lists, more extended criteria donor organs are being accepted, requiring optimization of the organs to increase utilization. Abdominal normothermic regional perfusion (aNRP) benefits the outcomes of transplanted livers and pancreatic islets, but its effects on donor kidneys subsequently preserved with (oxygenated) hypothermic machine perfusion (HMPO ₂ ) remain to be determined. This study examines the function and survival of an aNRP-preserved controlled donation after circulatory death (cDCD) kidneys followed by HMPO ₂ . Methods.: From October 2018 until June 2023, we evaluated all ≥50 y cDCD kidneys retrieved using aNRP during a pilot implementation project and compared posttransplant outcomes of these donor kidneys to those of cDCD kidneys retrieved by standard rapid retrieval during the same period. All kidneys received HMPO ₂ as standard preservation. This study primarily compared estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration), 1 y graft and recipient survival. Results.: Data of 70 aNRP-preserved kidneys were compared with a control group of 124 kidneys. One year estimated glomerular filtration rate was comparable between groups (40.4 mL/min/1.73 m ² [29.3-52.3] versus 40.0 mL/min/1.73 m ² [28.1-48.1]; P = 0.5) as well as graft and recipient survival at 1 y (81.4% versus 83.1%; hazard ratio, 1.1; 95% confidence interval [CI], 0.6-2.3; P = 0.63; 88.6% versus 88.7%, hazard ratio, 1.0; 95% CI, 0.4-2.4; P = 0.99, respectively). Primary nonfunction and delayed graft function were not significantly different (odds ratio, 1.3; 95% CI, 0.4-4.2; P = 0.68; odds ratio, 1.3; 95% CI, 0.7-2.5; P = 0.39). Conclusions.: This study demonstrates that aNRP-preserved kidneys from cDCD donors aged 50 y and older had comparable outcomes to kidneys retrieved with standard rapid retrieval, in the context of HMPO ₂ as a standard ex situ preservation technique. This differs from earlier studies showing improved results of aNRP in the context of cold storage without standard machine perfusion. With aNRP gaining interest because of its value for liver and pancreatic islet transplantation, a prospective randomized study should be performed to further analyze the benefit of continuous kidney HMP(O ₂ ) after aNRP.