Steady and pulsatile flow studies on a trileaflet heart valve prosthesis.

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Prosthetic Valve Design

Background:

• The demand for improved durability and function in trileaflet valves drives innovation.
• Existing prosthetic valves, including porcine and pericardial tissue valves, have limitations.
• Mechanical valves offer low profile designs but may have different hemodynamic profiles.

Purpose of the Study:

• To evaluate the fluid dynamic performance of the novel ABIOMED polymeric trileaflet valve prosthesis.
• To compare the ABIOMED valve's characteristics against current clinical tissue and mechanical valves.
• To identify areas for design improvement to enhance the valve's hemodynamic performance.

Main Methods:

• In vitro fluid dynamic studies were conducted in an aortic position simulation.
• Laser-Doppler anemometry was used for steady and pulsatile flow velocity measurements.
• Pressure drop and leaflet motion characteristics were analyzed and compared.

Main Results:

• The ABIOMED valve demonstrated improved leaflet motion and pressure drop compared to Carpentier-Edwards and Ionescu-Shiley tissue valves.
• It exhibited greater stenosis than St. Jude and Medtronic-Hall mechanical valves at normal cardiac outputs.
• Downstream flow was jet-like with elevated shear stresses, though lower than in tissue valves.

Conclusions:

• The ABIOMED polymeric trileaflet valve shows promise but requires further design optimization for enhanced fluid dynamics.
• Its current configuration, originally for valved conduits, may limit its aortic performance.
• Future iterations focusing on valve and stent design could improve hemodynamic efficiency and reduce stenosis.