A Comparison of Pulsatile Hypothermic and Normothermic Ex Vivo Machine Perfusion in a Porcine Kidney Model.

BACKGROUND Hypothermic Machine Perfusion (HMP) is a well-established method for deceased donor kidney preservation. Normothermic Machine Perfusion (NMP) might offer similar or greater advantages. We compared the two methods in an ex vivo perfusion model using 34 porcine kidneys. METHODS Thirty kidneys were stored on ice for 24h before undergoing 4h of HMP (n=15) or NMP (n=15) followed by 2h of normothermic ex vivo reperfusion with whole blood. Four kidneys underwent 28h of cold static storage (CSS) followed by 2h of normothermic ex vivo reperfusion. During the 2 hours of normothermic ex vivo reperfusion perfusate flow rates, urinary output and oxygen consumption rates were compared between all groups. RESULTS Porcine kidneys after HMP showed significantly higher urinary output- (5.31ml/min±2.06ml/min vs. 2.44ml/min±1.19ml/min, p=0.002), oxygen consumption- (22.71±6.27ml/min vs. 11.83±1.29ml/min, p=0.0016) and perfusate flow rates (46.24±12.49ml/min vs. 26.16±4.57ml/min, p=0.0051) than kidneys after NMP. Tunnel staining of tissue sections showed significantly higher rates of apoptosis in kidneys after NMP (p=0.027). CONCLUSIONS In our study, the direct comparison of HMP and NMP kidney perfusion in a translational model demonstrated superiority of HMP, however further in vivo studies would be needed to validate those results.