Kidney Injury Due to Warm Ischemia During Transplantation Can Be Reduced

The Effect of Recipient Back-Table Duration on Graft Outcome of Deceased Donor Kidneys: A Single-Center Prospective Cohort Study

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.

The Impact of Anastomosis Time During Kidney Transplantation on Graft Loss: A Eurotransplant Cohort Study

Recent studies raised the concern that warm ischemia during completion of vascular anastomoses in kidney implantation harms the transplant, but its precise impact on outcome and its interaction with other risk factors remain to be established. We investigated the relationship between anastomosis time and graft survival at 5 years after transplantation in 13 964 recipients of deceased donor solitary kidney transplants in the Eurotransplant region. Anastomosis time was independently associated with graft loss after adjusting for other risk factors (adjusted hazard ratio [HR] 1.10 for every 10-min increase, 95% confidence interval [CI] 1.06-1.14; p < 0.0001), whereas it did not influence recipient survival (HR 1.00, 95% CI 0.97-1.02). Kidneys from donation after circulatory death (DCD) were less tolerant of prolonged anastomosis time than kidneys from donation after brain death (p = 0.02 for interaction). The additive effect of anastomosis time with donor warm ischemia time (WIT) explains this observation because DCD status was no longer associated with graft survival when adjusted for this summed WIT, and there was no interaction between DCD status and summed WIT. Time to create the vascular anastomoses in kidney transplantation is associated with inferior transplant outcome, especially in recipients of DCD kidneys.

The influence of warm ischemia elimination on kidney injury during transplantation - clinical and molecular study

Kidney surface cooling was used during implantation to assess the effect of warm ischemia elimination on allograft function, histological changes and immune-related gene expression. 23 recipients were randomly assigned to a group operated on with kidney surface cooling during implantation (ice bag technique, IBT group), and the other 23 recipients receiving the contralateral kidney from the same donor were operated on with a standard technique. Three consecutive kidney core biopsies were obtained during the transplantation procedure: after organ recovery, after cold ischemia and after reperfusion. Gene expression levels were determined using low-density arrays (Format 32, TaqMan). The IBT group showed a significantly lower rate of detrimental events (delayed graft function and/or acute rejection, p = 0.015) as well as higher glomerular filtration rate on day 14 (p = 0.026). A greater decrease of MMP9 and LCN2 gene expression was seen in the IBT group during total ischemia (p = 0.003 and p = 0.018). Elimination of second warm ischemia reduced the number of detrimental events after kidney transplantation, and thus had influence on the short-term but not long-term allograft function. Surface cooling of the kidney during vascular anastomosis may reduce some detrimental effects of immune activation resulting from both brain death and ischemia-reperfusion injury.

Beneficial Effect of Short Pretransplant Period of Hypothermic Pulsatile Perfusion of the Warm-Ischemic Kidney after Cold Storage: Experimental Study

Warm ischemia (WI) produces a significant deleterious effect in potential kidney grafts. Hypothermic machine perfusion (HMP) seems to improve immediate graft function after transplant. Our aim was to analyze the effect of short pretransplant periods of pulsatile HMP on histology and renal injury in warm-ischemic kidneys. Twelve minipigs were used. WI was achieved in the right kidney by applying a vascular clamp for 45 min. After nephrectomy, autotransplant was performed following one of two strategies: cold storage of the kidneys or cold storage combined with perfusion in pulsatile HMP. The graft was removed early to study renal morphology, inflammation (fibrosis), and apoptosis. Proinflammatory activity and fibrosis were less pronounced after cold storage of the kidneys with HMP than after cold storage only. The use of HMP also decreased apoptosis compared with cold storage only. The detrimental effects on cells of an initial and prolonged period of WI seem to improve with a preservation protocol that includes a short period of pulsatile HMP after cold storage and immediately before the transplant, in comparison with cold storage only.