A miniature implantable axial flow ventricular assist device.

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Surgical Technology

Background:

• Development of a compact axial flow pump (86 mm length, 22 mm width, 95 g) in collaboration with NASA engineers.
• Pump specifications: 5-6 L/min flow against 100-mm Hg pressure, ~10,000 rpm, <10 W power consumption.

Purpose of the Study:

• To evaluate the performance and biocompatibility of a novel axial flow pump in a large animal model.
• To assess the pump's efficacy and safety for potential clinical application in cardiovascular support.

Main Methods:

• Implantation of the axial flow pump in 9 calves, with left ventricular inflow and descending thoracic aorta outflow via a Dacron graft.
• Monitoring of pump performance, physiological parameters, and systemic organ health for 1-3 months post-operation.

Main Results:

• Sustained pump operation (9,000-10,000 rpm, 7-9 W, 4-5 L/min output) in all animals for up to 3 months.
• Absence of thromboembolism and hemolysis (plasma-free hemoglobin 0.5-3 mg/dL) observed at autopsy.
• Normal physiological parameters (hemoglobin, BUN, creatinine, bilirubin) and negative bearing wear-tear tests.

Conclusions:

• The axial flow pump demonstrates highly gratifying performance characteristics in a calf model up to 90 days.
• Key indicators of success include consistent pump output (5 L/min), hemolysis within normal limits, and a complete absence of thromboembolism.
• The findings support the potential clinical utility of this device for cardiovascular support.