: Introduction: Ageing of the general population has led to an increase in the use of suboptimal kidneys from expanded criteria donation after brain death (ECD-DBD) and donation after circulatory death (DCD) donors. However, these kidneys have inferior graft outcomes and lower rates of immediate function. Normothermic machine perfusion (NMP) may improve outcomes of these suboptimal donor kidneys. Previous non-randomized studies have shown the safety of this technique and suggested its efficacy in improving the proportion of immediate functioning kidneys compared to static cold storage (SCS). However, its additional value to hypothermic machine perfusion (HMP), which has already been proved superior to SCS, has not yet been established. Methods and analysis: This single-center, open-label, randomized controlled trial aims to assess immediate kidney function after 120 minutes additional, end-ischemic NMP compared to HMP alone. Immediate kidney function is defined as no dialysis treatment in the first week after transplant. Eighty recipients on dialysis at the time of transplant who receive an ECD-DBD or DCD kidney graft are eligible for inclusion. In the NMP group, the donor kidney is taken of HMP upon arrival in the recipient hospital and thereafter put on NMP for 120 minutes at 37 degrees Celsius followed by transplantation. In the control group, donor kidneys stay on HMP until transplantation. The primary outcome is immediate kidney function. Ethics and dissemination: The protocol has been approved by the Medical Ethical Committee of Erasmus Medical Center (2020-0366). Results of this study will be submitted to peer-reviewed journals. Registration: registered in clinicaltrials.gov (NCT04882254). Highlights:

Hypothermic machine perfusion(HMP) is considered the gold standard in kidney preservation. Despite this, grafts from extended criteria donors(ECD-DBD) and donation after circulatory death(DCD) remain at high risk of delayed graft function(DGF). Normothermic machine perfusion(NMP) during the preservation process could alternatively preserve physiological activity. We investigated the value of additional NMP to HMP in ECD-DBD and DCD kidney transplantation. This is a single-centre, open-label, superiority, randomized controlled trial. Patients were randomized to receive a kidney that was either preserved on HMP and two hours of end-ischemic HMP+NMP(intervention group) or HMP only(control group). Primary outcome was the incidence of immediate graft function(IGF). A total of 80 patients were included in the intention-to-treat analysis, of which 41 received a kidney that was preserved on HMP and HMP+NMP and 39 received a graft that was preserved on HMP alone. Incidence of IGF was 16/41(39%) in HMP+NMP group compared to 19/39(49%) in the HMP group, with no significant difference between both groups(OR: 0.68, 95% CI: 0.28-1.64, p=0.38). There was no statistically significant difference in any of the secondary outcomes. The addition of two hours end-ischemic NMP does not improve early graft outcomes in kidney transplantation compared to HMP alone.

Background: Human donor kidneys release (pro)renin, erythropoietin (EPO), active vitamin D, and urodilatin during normothermic machine perfusion (NMP). However, whether the endocrine function of donor kidneys is associated with post‐transplant kidney function is unclear.Methods: We studied 28 donor kidneys, including seven from donation after brain death (DBD) donors and 21 from donation after circulatory death (DCD) donors. Prior to transplantation, we measured levels of (pro)renin, EPO, 1,25(OH)₂D in the perfusate, and urodilatin in urine during NMP. Hormone release rates were compared between kidneys with and without delayed graft function (DGF), and correlations were assessed between hormone release rates and donor characteristics and transplant outcome, including DGF duration, serum creatinine levels at 1‐week post‐transplant, and estimated glomerular filtration rate at 1‐month post‐transplant.Results: DBD kidneys secreted significantly less EPO and more active vitamin D than DCD kidneys. Kidneys with DGF exhibited significantly higher release rates of active vitamin D and lower release rates of urodilatin compared to those without DGF. In addition, EPO release rate was positively correlated with serum creatinine levels at 1‐week post‐transplant. Finally, urodilatin release rates were negatively correlated with DGF duration and positively correlated with urine output.Conclusions: Urodilatin release in urine and EPO and active vitamin D release in perfusate during NMP may serve as potential biomarkers for predicting early post‐transplant outcomes.Trial Registration: ClinicalTrials.gov identifier: NCT04882254

With an increasingly aging population, both end-stage renal disease and peripheral artery disease become more prevalent. Peripheral artery disease is increasingly treated with endovascular procedures. Endovascular stenting of the external iliac artery (EIA) is often considered a contraindication for kidney transplantation, as clamping of the artery could result in possible injuring of the stent. In this study, we describe our first two cases of kidney transplantation with a graft placed on a self-expandable metal stent and a covered stent as part of an endovascular repair of the aortic bifurcation, using endovascular balloon occlusion to occlude the proximal side of the EIA. Six months after transplantation, both recipients have good kidney function without any signs of ischemia of the ipsilateral limb. This study shows that it is feasible to place a kidney graft on an endovascular stent.

Background: Both hypothermic machine perfusion (HMP) and normothermic machine perfusion (NMP) are increasingly used for preservation of deceased donor kidneys. However, especially NMP can pose as a risk for microbial contamination of the kidney graft as the 37°C perfusate can act as a breeding ground for microbial contaminants.Methods: In this study, we investigated the cultures of HMP and NMP perfusates of deceased donor kidneys.Results: Between January 2021 and April 2024, a total of 99 perfusates were examined (73 HMP and 26 NMP perfusates)‐. We found that contamination of HMP perfusate was common, occurring in 21 of 73 cultures (29%). Most bacteria originated from the skin. Microbial contamination during NMP was rare, occurring only in 2 of 26 cultures (8%). Microbial contamination during machine perfusion did not lead to infectious complications in the recipients.Conclusion: Machine perfusion poses a very limited risk of infection in kidney transplant recipients. image

Background: Little is known about the influence of the duration of the kidney back-table preparation period and kidney temperature on graft outcomes after transplantation. The aim of this study is to investigate the back-table duration and its relation to graft outcome and the relation between kidney temperature and graft outcome. Methods: In this prospective cohort study, deceased donor kidney temperature is measured at fixed time points using an infrared thermometer during back-table preparation and transplantation. Additionally, the back-table duration is measured using a timer. Results: Between September 2020 and July 2021, 49 kidneys were prospectively included in this study. Median back-table duration was 33.7 (standard deviation ± 14.1) min and donor kidney temperature increased up to 14.9 °C (±2.8) after 60 min of back-table preparation. Mean implantation time was 24.9 (±7.6) min and kidney temperature increased up to 25.9 °C (±2.4) after 30 min of implantation time. Longer back-table duration was significantly associated with higher rates of delayed graft function (p = 0.037). However, this observation did not sustain at 3 and 6-months post-transplantation. No association was found between kidney temperature and graft outcomes. Conclusion: Longer back-table duration is significantly associated with DGF after deceased donor kidney transplantation. No association was observed between kidney temperature and graft outcomes of deceased donor kidneys.