Comparison of nonpulsatile and pulsatile extracorporeal circulation on renal cortical blood flow

Radioactive microspheres were used to compare renal cortical blood flow with pulsatile and nonpulsatile extracorporeal perfusion in mongrel dogs. No difference was found in total renal cortical flow or in flow distribution using pulsatile compared with nonpulsatile perfusion when mean perfusion pressure was held constant at a high (80 mm Hg) or low (50 mm Hg) level. Although the present investigation does not resolve the question of whether pulsatile perfusion has advantages over nonpulsatile perfusion in maintaining renal function, the data indicate that any differences between the two techniques must be explained by a mechanism other than increased total cortical blood flow or by redistribution of cortical flow.