In vitro assessment of the unloading and perfusion capacities of the PUCA II and the IABP.

The PUCA II pump is a minimally invasive intra-arterial left ventricular assist device that can be used as an alternative for the intra-aortic balloon pump (IABP). In this study, we assessed the cardiac unloading and organ perfusion capacities of both PUCA II and IABP in an in vitro set up, consisting of a heart simulator and a silicone arterial tree, mimicking anatomical geometry and flow distribution. The IABP was positioned in the descending aorta, while the PUCA II was tested both in 'trans-aortic' and 'abdominal' positions. All devices were driven by the same Arrow AutoCat IABP driver at different pump rates. Apart from flow, arterial pressure and pulse pressure, we also calculated haemodynamic indices for myocardial oxygen supply and demand. The 'abdominal' PUCA II assist and the IABP both provide mild unloading of the heart, and a limited improvement of arterial pressure and flow. The 'trans-aortic' PUCA II assist greatly enhances flow and pressure, but does not unload the heart properly in the tested configuration.