Effects of arterial pressure in an experimental isolated haemoperfused porcine kidney preservation system

Background: Normothermic preservation provides metabolic support to an ischaemically damaged organ before use as a kidney transplant. Optimal conditions for ex vivo preservation have not yet been established. This study examined the effects of arterial pressure on renal preservation using isolated haemoperfused kidneys. Methods: An isolated organ preservation system, developed using cardiopulmonary bypass technology, was used to perfuse porcine kidneys with normothermic oxygenated blood. Groups of kidneys (n = 6) were perfused at a mean arterial pressure of 95, 75 or 55 mmHg. Results: Kidneys perfused at the higher mean arterial pressures of 95 and 75 mmRg demonstrated improved renal function: mean(s.d.) area under the curve (AUC) for creatinine clearance 71(19) and 55(30) respectively versus 14(12) in the 55-mmHg group, P = 0.002; AUC for serum creatinine 938(140) and 1290(394) versus 2404(595), P = 0.003. The higher perfusion pressures were also associated with better acid-base homeostasis and improved renal haemodynamics. Conclusion: Mean arterial pressures of either 95 or 75 mmHg were capable of sustaining physiological renal function, but kidneys in the 95-mmHg group demonstrated superior renal function overall.