Early experience with a new technique and technology designed for the study of pulsatile cardiopulmonary bypass in the rat

The benefits of pulsatile flow during the period of cardiopulmonary bypass (CPB) applied during open-heart surgery remains controversial. We have developed a rodent (rat) model of CBP that has been designed to functionally mimic the clinical setting, principally, but not solely, for the study of pulsatile CPB. The successful development of this model centres on the design of the bypass circuitry and the surgical approach employed. The entire circuit is similar to clinical equipment in terms of its construction, configuration, performance, material surface area to blood volume ratio, and priming volume to blood volume ratio. The overall priming volume of the perfusion circuitry is less than 12 ml. Early studies confirm that the pumping technology functions well, gas exchange was adequate at all times, and blood pressure exhibited a normal CPB profile and haemodynamic response to pulsatile blood flow. We conclude that this is an effective tool for investigating the pathophysiology of pulsatile blood flow during CPB.