DESIGN OF A PHYSIOLOGICAL PULSATILE FLOW CARDIOPULMONARY BYPASS SYSTEM FOR NEONATES AND INFANTS

Cardiopulmonary bypass surgical techniques that allow a surgeon to ope rate on the infant's heart use an extracorporeal circuit consisting of a pump, oxygenator, arterial and venous reservoirs, cannulae, an arte rial filter, and tubing. The extracorporeal technique currently used i n infants and neonates is sometimes associated with neurologic damage. We are developing a modified cardiopulmonary bypass system for neonat es that has been tested in vitro and in one animal in vivo. Unlike oth er extracorporeal circuits which use steady flow, this system utilizes pulsatile flow, a low prime volume (500ml) and a closed circuit. Duri ng in vitro experiments the pseudo patient's mean arterial pressure wa s kept constant at 40 mmHg and the extracorporeal circuit pressure did not exceed a mean pressure of 200 mmHg. In our single in vivo experim ent, the primary objective was to determine whether physiologic pulsat ility with a 10F (3.3 mm) aortic cannula could be achieved. The result s suggest that this is possible.