An improved method of myocardial protection with pulsation during cardiopulmonary bypass

A new valveless pulsatile assist device (PAD) has been developed that converts roller pump flow into synchronized pulsatile flow. The PAD can also be used as an arterial counterpulsator ACtP) before and after cardiopulmonary bypass (CPB). The PAD was employed in 100 adult patients undergoing open heart surgery for coronary artery and/or valvular heart disease. Seventy-three of these patients were NYHA class III or IV, had ejection fractions of <0.3, or an LVEDP ≥ 18 mm Hg. Sixty-one patients underwent coronary artery bypass alone, 17 valve replacement alone, three ventricular aneurysm alone, 12 combined coronaries and valves, and seven combined coronaries and ventricular aneurysms. The device functioned as a hemodynamically effective ACtP before and after CPB. During CPB, pulse pressures of 40-50 mm Hg were readily obtained. Urinary outputs during CPB were increased on the PAD when compared to a control group (9.18±0.68 cc/min vs 3.90±0.34 cc/min). In addition, during CPB, coronary graft blood flow (CBF) increased an average of 21.4±6.1% with the PAD, and after CPB, CBF increased an average of 25.0±5.9%. Free plasma hemoglobins after CPB were not elevated. Only one patient had a perioperative myocardial infarction, and this patient was successfully treated with intra-aortic balloon pumping. It is suggested from these data that use of the PAD may decrease both the incidence of perioperative myocardial infarction and the need for postoperative intra-aortic balloon pumping.