Biomechanical comparison between mono-, bi-, and tricuspid valve architectures

Background: An understanding of the relationship between venous valve architecture and associated fluid and solid mechanical forces will undoubtedly advance prosthesis design and treatments. The objective of the current study was to compare three valve architectures (mono-, bi-, and tricuspid) and the implications of these designs on the fluid and solid mechanics of the valve leaflets. The hypothesis is that the bicuspid valve has the lowest mechanical cost, defined as the ratio of leaflet wall stress and fluid wall shear stress (WSS), for the venous environment as compared with mono- and tricuspid valves. Methods: To address this hypothesis, fully coupled, two-way fluid-structure interaction computational models were developed and simulated for the three types of valves. Results: The numerical simulations showed that the mean fluid WSS of the bicuspid valve was generally higher than the tricuspid valve, which was further higher than the monocuspid valve. The mean leaflet wall stress of the bicuspid valve was lower than the tricuspid valve, which was further lower than the monocuspid valve. Therefore, the mechanical cost, which was defined as solid wall stress/fluid WSS, of the bicuspid valve was the lowest. Conclusions: The lower mechanical cost may be a reason why the bicuspid valve is the dominant design in the venous system. This knowledge provides guidance for the design of novel venous prosthetic valves and may shed light on venous valve disease when the architecture of the valve is altered.