Dynamic Parameters of Hypothermic Machine Perfusion-An Image of Initial Graft Function in Adult Kidney Transplantation?

Kidney allografts are subjected to ischemia reperfusion injury during the process of transplantation. Hypothermic machine perfusion (HMP) of deceased donor kidneys from organ procurement until transplantation is associated with a superior outcome when compared to static cold storage (SCS). Nevertheless, cold ischemia time (CIT) remains an independent risk factor for delayed graft function (DGF) in HMP-preserved kidney allografts as well. We performed a retrospective single-center study including all adult recipients who underwent deceased donor kidney-only transplantation at our center between January 2019 and December 2020. Beside the clinicopathological donor and recipient data, flow and resistance data during HMP were assessed. Short- and long-term kidney allograft outcome after end-ischemic HMP and SCS were analyzed and compared. Organ preservation consisted of either SCS ( n = 88) or HMP ( n = 45). There were no differences in recipient demographics and donor details between groups. CIT was significantly longer in the HMP group (16.5 [8.5-28.5] vs. 11.3 [5.4-24.1], p < 0.0001). The incidence of DGF as well as serum creatinine at discharge and at 1 year post transplant were comparable between groups. Duration of SCS prior to HMP was comparable among grafts with and without DGF. Flow rate and organ resistance at the start of HMP were significantly worse in DGF-kidney grafts (arterial flow 22.50 [18.00-48.00] vs. 51.83 [25.50-92.67] ml/min, p = 0.0256; organ resistance 123.33 [57.67-165.50] vs. 51.33 [28.17-111.50] mmHg/mL/min, p = 0.0050). Recipients with DGF had significantly worse creatinine levels at discharge (2.54 [1.08-7.64] vs. 1.67 [0.90-6.56], p < 0.0001) and at 1 year post transplant (1.80 [1.09-7.95] vs. 1.59 [0.87-7.40], p = 0.0105). In conclusion, baseline HMP parameters could be applied as a predictive tool for initial graft function, which in turn determines long-term outcome.