A Parametric Finite Element Analysis of Chick Embryo Aortic Valve Leaflet Biomechanics

The anatomy and mechanical strength of aortic valve leaflets are critical determinants of the valve biomechanical behavior and long-term structural integrity. The embryonic de-velopmental period, when valves are forming, is critical in establishing baseline leaflet properties. Yet, final stages of valve development are not well understood. This study employs a parametric approach to model the leaflet anatomy of an HH40 chick embryo aortic valve approximating its native curvature. To perform biomechanical analysis, a pressure profile derived from in-ovo Doppler ultrasound measurements was applied, and an Ogden hyper elastic material model was employed following a sensitivity analysis. To determine the effect of valve anatomy on leaflet tissue deformation and stresses, we changed the leaflet midline curve from its native curvature to a linear profile, and quan-tified biomechanical responses. Our analysis revealed a strong decrease in average leaflet effective stress as its midline curvature was shifted towards a linear profile. However, this reduction in average stress was at the expense of a biomechanical trade-off. The shift induced a progressive localization of stress concentration at the leaflet tips and commis-sures, and a distinct bending deformation mode at the tip under peak load. Moreover, the midline curvature shift had a non-linear impact on function: the valve geometric orifice area (GOA) increased initially with the anatomy shift but then reached a maximum and subsequently decreased. Our findings demonstrate that while the curvature of the leaflet midline modulates tissue stress during valve opening a low-stress anatomy does not align with hemodynamic performance. This work characterizes competing leaflet biomechan-ical responses that shape valve leaflet formation, providing fundamental insights into developmental valve biomechanics.