Three-dimensional flow analysis of a mechanical bileaflet mitral prosthesis

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Fluid Dynamics

Background:

• Mechanical heart valves are crucial for treating valvular heart disease.
• Understanding hemodynamic performance and acoustic properties is vital for valve design.
• Previous studies have not fully explored the impact of valve orientation and design on mitral valve flow dynamics.

Purpose of the Study:

• To compare the hemodynamic performance of Jyros (JR), Advancing The Standard (ATS), and St. Jude Medical (SJM) mitral valves.
• To investigate the effects of valve design and orientation on flow patterns and closing sounds.
• To analyze valve closing noise in relation to fluid dynamics.

Main Methods:

• Utilized particle tracking velocimetry (PTV) and particle image velocimetry (PIV) for flow visualization.
• Employed high-speed video to map the velocity field around the valves.
• Conducted sound measurements to quantify valve closing noise.

Main Results:

• SJM valve showed distinct circulatory flow in antianatomical orientation; JR and ATS valves generated higher, divergent flow anatomically.
• JR valve in antianatomical orientation had less distinct flow patterns and lower closing noise compared to SJM.
• All three valves exhibited symmetrical twin circulations below the mitral valve, with differing downward flow patterns.

Conclusions:

• Valve design and orientation significantly alter mitral valve hemodynamics.
• Observed flow differences may contribute to variations in valve closing sounds.
• These findings provide insights for optimizing mechanical mitral valve design and implantation.