The Effects of IABP on Central and Peripheral Organ Blood Flow in a Dog Model

Abstract

Cardiogenic shock (CS) is a circulatory failure with a poor prognosis. The intra-aortic balloon pump (IABP), one of the mechanical circulatory support devices, is the most widely used for treating CS. However, clinical trials have not demonstrated its efficacy in treating CS with IABP. In this study, we systematically examined the effects of IABP on perfusion of the central and peripheral organs, including the brain and kidneys, in addition to the systemic and coronary circulation, and explored the optimization and maximization of IABP’s effects. Using a normal canine model (N＝1), we measured blood pressure, ventricular pressure, left and right atrial pressures, cardiac output, and blood flow in the coronary, carotid, and renal arteries, comparing the presence and absence of IABP. To fit the diameter of the dog’s aorta, we custom-made two balloons with diameters of 6mm and 8mm. Diastolic augmentation and systolic unloading by the IABP were observed in the aortic pressure waveform, and both balloons increased coronary flow and decreased left ventricular systolic pressure. Still, the 8mm balloon had a greater effect than the 6mm balloon. The impact on aortic pressure and cardiac output was minimal. However, distal aortic pressure decreased, and renal blood flow was reduced with both balloons. This study revealed that balloon diameter significantly affects the efficacy of IABP and suggested that this model and experimental system are useful for optimizing IABP.