Toward a Bioinspired Tissue Engineered Mitral Valve: In Silico Optimization of the Chordal Apparatus in a Polymeric Mitral Valve

Abstract

Tissue-engineered heart valve (TEHV) scaffolds are designed as off-the-shelf alternatives, eliminating the need for organ donors and promoting native tissue regeneration. This study presents an in silico investigation of a bioinspired, polymeric, stentless mitral valve (MV) prosthesis, focusing on engineering the chordal apparatus (CA) to optimize valve performance. Specifically, the study explores the influence of chordae tendineae (CT) number, length, and anchoring position on functional outcomes.

Numerical simulations were conducted using Abaqus/Explicit. The mitral leaflets and CT were modelled using shell (S4) and truss (T3D2) elements, respectively. To replicate the anisotropic mechanical behaviour of native mitral leaflets, an anisotropic Fan–Sacks constitutive model was employed. The CTs were described with an Ogden hyperelastic model. Boundary conditions included an encastred annulus and papillary muscles (PM) pinned at their time-averaged positions. The leaflets were loaded with physiological atrial and ventricular pressures.

Parametric variations included CT number (2, 4, 6, 8), CT length (80%, 100%, 120% of physiological length), and anchoring distribution along the leaflet free edge. Performance metrics evaluated included von Mises stress (σ_VM), bulging height (BH), coaptation length (CL), and geometric orifice area (GOA), benchmarked against native valve thresholds.

The optimal configuration featured 8 CT (4 per leaflet), at 80% of physiological length, with anchoring points along the free edge. This setup enhanced CL (>5 mm) and GOA (>1.5 cm²), while reducing σ_VM (<1.5 MPa) and BH (<2 mm). These results provide crucial guidance for the design of the engineered BIOMITRAL valve incorporating a bioinspired CA.