Experimental Study On Continuous Normothermic Machine Perfusion Preservation For Kidney From Donation After Cardiac Death

ObjectiveTo observe the preservation effect of continuous normothermic machine perfusion on kidney from donation after cardiac death,and explore the effect of continuous normothermic machine perfusion preservation on the activation level of caspase-9 and the level of total nicotinamide adenine dinucleotide in renal tissue.MethodsSixteen healthy Bama miniature pigs were randomLy divided into two groups: NMP group(n=8)and HMP group(n=8).In the HMP group and the NMP group,the model of donor kidney after cardiac death was established by blocking the renal arteriovenous vein for 30 min,then the donor kidneys were obtained.The HMP group was preserved by hypothermic machine perfusion for 8h,and the NMP group was preserved by continuous normothermic machine perfusion for 8h.The two groups were given reperfusion for 2h in vitro to simulate transplantation,and the beginning of the reperfusion phase,one hour after the beginning of the reperfusion phase,and the end of the reperfusion phase respectively recorded as T0,T1,and T2.The preservation effect of continuous normothermic machine perfusion on donor kidney after cardiac death was evaluated by pathology,NMP score,urine volume,oxygen consumption,resistance index,urinary creatinine/perfusate creatinine value and injury markers.The change in the activation level of caspase-9 and the level of total nicotinamide adenine dinucleotide were determined using commercial kits.ResultsAt T0,the renal tubules of NMP group showed moderate watery,moderate vacuolar degeneration,and focal coagulative necrosis,and the renal tubules of HMP group showed mild watery and vacuolar degeneration.At T2,the renal tubules of HMP group and NMP group both showed moderate watery,moderate vacuolar degeneration,and focal coagulative necrosis.The urine volume and urinary creatinine/perfusate creatinine value of NMP group were significantly higher than those of HMP group at T1(P<0.05),and there was no significant difference in the urine volume and urinary creatinine/perfusate creatinine value between NMP group and HMP group at T2(P>0.05).There was no significant difference in aspartate aminotransferase level and lactate dehydrogenase level in perfusate between HMP group and NMP group at T0,T1 and T2(P>0.05).There was no significant difference in alkaline phosphatase level and gamma-glutamyl transpeptidase level in perfusate between HMP group and NMP group at T0(P>0.05),and the alkaline phosphatase level and gamma-glutamyl transpeptidase level in the NMP group were significantly lower than those in the HMP group at T1 and T2(P<0.05).The resistance index of HMP group was significantly higher than that of NMP group at T1(P<0.05),there was no significant difference in resistance index between HMP group and NMP group at T2(P>0.05).The NMP score of NMP group significantly lower than that of HMP group at T1(P<0.05),and there was no significant difference in NMP score between NMP group and HMP group at T2(P>0.05).The oxygen consumption of NMP group was significantly higher than that of HMP group at T2(P<0.05).The total nicotinamide adenine dinucleotide level of renal tissue in NMP group was significantly higher than that in HMP group at T2(P<0.05),and the activation level of cysteinyl aspartate specific proteinase-9 of renal tissue in NMP group was significantly lower than that in HMP group at T2(P<0.05).ConclusionsContinuous normothermic machine perfusion can significantly improve the ischemia-reperfusion injury and renal function of porcine kidney from donation after cardiac death by simulating physiological environment,maintaining cell metabolism and avoiding damage from hypothermia,which may be related to the change of the activation level of caspase-9 and the level of total nicotinamide adenine dinucleotide in renal tissue.