Subnormothermic Ex Vivo Machine Perfusion for the Preservation of Donation After Circulatory Death Porcine Kidney Grafts: Optimizing Organ Demand and Function.

BACKGROUND

To enhance the usage of marginal kidney grafts, ex vivo machine perfusion represents a promising alternative to static cold storage. Subnormothermic ex vivo kidney perfusion (SEVKP) has the potential to merge the benefits of both hypothermic machine perfusion (HMP) and normothermic ex vivo kidney perfusion (NEVKP) but has been minimally investigated so far. This study aimed to determine the applicability of SEVKP in kidney preservation.

METHODS

Pig kidneys underwent 60 min of warm ischemia followed by 7.5 h of either HMP (4 °C), SEVKP (22 °C), or NEVKP (37 °C). After removal of the contralateral kidney, the grafts were autotransplanted, and the animals were monitored for 3 d.

RESULTS

Grafts preserved using NEVKP exhibited similar early postoperative functions to those preserved with SEVKP, whereas HMP-preserved grafts showed inferior function. When comparing the HMP and SEVKP groups, serum creatinine levels differed significantly on all postoperative days, with consistently higher values observed in the HMP group. By postoperative day 3, creatinine clearance was higher in both the NEVKP and SEVKP groups compared with the HMP group. Additionally, urinary neutrophil gelatinase-associated lipocalin levels were significantly lower on postoperative day 3 in the NEVKP and SEVKP groups than in the HMP group.

CONCLUSIONS

Despite reduced metabolic activity during SEVKP, grafts preserved with SEVKP versus NEVKP demonstrated no statistically significant differences in early posttransplant function. Both groups showed improved kidney function and less kidney injury compared with grafts preserved with HMP.