Renal Resistance Trend During Hypothermic Machine Perfusion Is More Predictive of Postoperative Outcome Than Biopsy Score: Preliminary Experience in 35 Consecutive Kidney Transplantations

Abstract

Hypothermic machine perfusion (HPM) grants a better postoperative outcome in transplantation of organs procured from extended criteria donors (ECDs) and donors after cardiac death (DCD). So far, the only available parameter for outcome prediction concerning those organs is pretransplant biopsy score. The aim of this study is to evaluate whether renal resistance (RR) trend during HPM may be used as a predictive marker for post-transplantation outcome. From December 2015 to present, HMP has been systematically applied to all organs from ECDs and DCD. All grafts underwent pretransplantation biopsy evaluation using Karpinski's histological score. Only organs that reached RR value ≤1.0 within 3 hours of perfusion were transplanted. Single kidney transplantation (SKT) or double kidney transplantation (DKT) were performed according to biopsy score results. Sixty-five HMPs were performed (58 from ECDs and 7 from DCD/ECMO donors). Fifteen kidneys were insufficiently reconditioned (RR > 1) and were therefore discarded. Forty-nine kidneys were transplanted, divided between 21 SKT and 14 DKT. Overall primary nonfunction (PNF) and delayed graft function (DGF) rate were 2.9 and 17.1%, respectively. DGF were more common in kidneys from DCD (67 vs. 7%; P = 0.004). Biopsy score did not correlate with PNF/DGF rate (P = 0.870) and postoperative creatinine trend (P = 0.796). Recipients of kidneys that reached RR ≤ 1.0 within 1 hour of HMP had a lower PNF/DGF rate (11 vs. 44%; P = 0.033) and faster serum creatinine decrease (POD10 creatinine: 1.79 mg/dL vs. 4.33 mg/dL; P = 0.019). RR trend is more predictive of post-transplantation outcome than biopsy score. Hence, RR trend should be taken into account in the pretransplantation evaluation of the organs.

Decrease of renal resistance during hypothermic oxygenated machine perfusion is associated with early allograft function in extended criteria donation kidney transplantation

“…The kidney donor profile index (KDPI) was implemented in an attempt to objectively assess KA quality and is based on a subjective macroscopic evaluation during retrieval and before KA implantation 12 , 13 . Real-time detection of perfusion parameters, such as flow- and renal vascular resistance (RR), for viability- and allograft quality assessment during machine perfusion are becoming increasingly important 13 , 14 . Although, tissue oxygen consumption is markedly decreased at 4–10 °C, there is still a significant cellular metabolism 15 .…”

Effects of Delayed Hypothermic Machine Perfusion on Kidney Grafts with a Preliminary Period of Static Cold Storage and a Total Cold Ischemia Time of Over 24 Hours

“…16], with a higher predictive value than graft biopsies scores [16]. The reported advantages rely on a real-time, objective, noninvasive evaluation of the whole organ, which might be productively used in the clinical decision-making process [16,17]. In the present analysis, a significant improvement of arterial resistance and flow during perfusion was observed, although the magnitude of this improvement was not directly correlated with HMP duration.…”

“…Moreover, the vascular resistance trend during HMP has been advocated as a reliable predictor of kidney graft function and risk of DGF/primary non-function [14. 16], with a higher predictive value than graft biopsies scores [16]. The reported advantages rely on a real-time, objective, noninvasive evaluation of the whole organ, which might be productively used in the clinical decision-making process [16,17].…”

Potential Applications of Extracellular Vesicles in Solid Organ Transplantation

“…In order to increase the number of successful transplants, the use of machine perfusion is currently proposed to ameliorate the function of organs from marginal donors such as DCDs and ECDs. Dynamic perfusion of organs appears a useful strategy to evaluate pretransplant graft function, limiting the discard rate [30][31][32]. Moreover, this approach reduces the incidence of DGF in recipients receiving organs from ECDs and DCDs.…”