O242: Prolonged subnormothermic acellular machine perfusion of human kidneys

Abstract

Abstract Introduction Prolonged periods of ex vivo perfusion are required to effectively deliver regenerative therapies directly to a kidney before transplantation. This provides time to start repair processes and reduce the likelihood of early graft dysfunction. The aim of this study was to assess the capability of extending the preservation interval using subnormothermic acelllular machine perfusion (SNAP). Methods After a period of static cold storage, 12 human kidneys declined for transplantation were perfused with an oxygenated human serum albumin-based solution at 32°C for 6, 12 or 24h (n=4 per group). After preservation all kidneys were reperfused with a red blood cell-based solution at 37°C for 4h for assessment. Results Functional parameters remained stable during SNAP in all kidneys. However, the perfusate flow rate was significantly lower in the 24h group (24h 166±45, 12h 266±45, 6h 214±36 mL/min/100g; P=0.008). After reperfusion, levels of urinary neutrophil gelatinase-associated lipocalin (uNGAL), insulin-like growth factor binding protein 7 (IGFBP7) and liver-type fatty acid-binding protein (L-FABP) were similar between groups (P>0.05). Levels of oxygen consumption were significantly lower in 24h kidneys compared to 12h (24h 1.45±0.86, 12h 4.3±1.78 mL/min/100g; P=0.0294). Histological evaluation showed a preserved renal morphology in all kidneys, except for the 24h group which showed a mild increase in tubular and endothelial damage. Conclusion This study demonstrated that human kidneys can be successfully preserved with SNAP for up to 12h. There was some evidence of additional ischaemic injury in the 24h SNAP kidneys which warrants further investigation.