Comparison of In Vitro and In Vivo Testing of Fluid Diodes as a Pulmonary Heart Valve Replacement

The operating pressures in the right heart are significantly lower than those of the left heart and with marked differences in the circulation impedances. The pulmonary circulation shows a tolerance for mild regurgitation and pressure gradient [1]. Pulmonary regurgitation fractions on the order of 20% and transvalvular pressure gradients of less than 25mm Hg are considered mild [2]. Given this tolerance, we examine the concept of using a motionless valve to regulate flow in the pulmonary position. In a previous study, the use of fluid diodes was shown to be a promising concept for use as a pulmonary valve [3]. In this study, we test a fluid diode both in a bench top circulatory system [4] and in a swine model and compare the pressure gradients and regurgitant fractions.