Isolated kidney perfusion: the influence of pulsatile flow.

Within the scope of transplantation research, ex vivo kidney perfusion has been proven an attractive model to study ischemia-reperfusion and preservation injury. Renal perfusion techniques also occupy scientists with the aim to optimize organ reconditioning and preparation prior to transplantation. This study investigated the influence of a pulsatile perfusion pattern that brings flow conditions closer to physiological situations, on renal perfusion characteristic and kidney function in the isolated perfused kidney. Kidneys were perfused via a roller pump at constant pressure set to 90 mmHg, or with addition of pulsatile pressure peaks (90/70 mmHg; 60/min) using an adjustable positive displacement pump. It was found that pulsatile pressure significantly enhanced renal flow rates as compared to non-pulsatile perfusion mode, especially after preceding preservation of the kidney by static cold storage. The improved vascular conductivity went along with a notable improvement of clearance of creatinine, sodium reabsorption and reduced tubular cell injury (Loss of fatty acid binding protein). The better vascular conductance upon pulsatile perfusion could be attributed to improved endothelial release of nitic oxide and reduced secretion of endothelin-1 into the perfusate. It is concluded, that pulsatile perfusion mode should be preferred in isolated kidney perfusion as resulting in better preservation/recovery of renal perfusion and function.