In Vivo Feasibility Study of an Intra-Atrial Blood Pump for Partial Support of the Left Ventricle*.

We are designing an intra-atrial pump (IAP) that will be affixed to the atrial septum and support the compromised left ventricle (LV) in patients with early-stage heart failure without harming the ventricular tissue. It will operate in parallel with the LV, drawing blood from the left atrium and unloading the LV. In previous hydraulic and hemodynamic studies, different blade geometries were tested for the IAP, and the hemodynamic results obtained using a mock circulatory loop showed that the IAP can successfully reduce end-diastolic volume and increase the total systemic flow rate. In the current study, we used a bovine model to validate the in vitro hemodynamic results and better understand how the IAP interacts with the cardiovascular system in vivo. Because this was the first study assessing the complete device in a living system, it was also necessary to determine the best manufacturing techniques and ideal sensor placements. In the bovine model, we were able to successfully implant the IAP across the atrial septum with the outflow graft connected to a peripheral artery. The implanted IAP was capable of providing partial support (1-3 L/min) in vivo. These results indicate that atrial cannulation is feasible and creates a beneficial hemodynamic environment.