Performance of a 3-bladed propeller pump to provide cavopulmonary assist in the failing Fontan circulation.

Abstract

We hypothesized that a propeller pump design would function optimally to provide cavopulmonary assist in a univentricular Fontan circulation. The hydraulic and hemolysis performance of a rigid three-bladed propeller prototype (similar to a folding propeller design) was characterized. Pressure and flow measurements were taken for flow rates of 0.5 to 3 liters per minute (LPM) for 5,000 to 7,000 revolutions per minute (RPM) using a blood analog fluid. Hemolysis testing was performed using fresh bovine blood for 2 LPM at 6,000 RPM for a 6-hour duration. The prototype performed well over the design operating range by producing a pressure rise of 5 to 50 mm Hg. Plasma free hemoglobin concentration remained less than 15 mg/dL. The normalized index of hemolysis peaked during the first hour, and then remained less than 10 mg/dL thereafter. A propeller pump has the pressure-flow characteristics and minimal risk of hemolysis and venous pathway obstruction which make it ideal for temporary cavopulmonary assist. This type of device has the potential to provide a new therapeutic option for patients with failing univentricular Fontan physiology as a bridge-to-recovery or transplantation.