Reproducing Anisotropic Properties in Personalized Mitral Valve Models to Improve Hemodynamic Behavior

Abstract Mitral valve insufficiency can be surgically corrected by minimally invasive mitral valve surgery. This approach is difficult to learn and training opportunities are still limited. Therefore, we built a physical mitral valve flow simulator to accommodate patient-individual valve models. The models must fulfill certain material properties to replicate adequate dynamic behavior, while being surgically modifiable. We developed two approaches for manufacturing complex anisotropic physiological mitral valve tissue, the first one being a thermoformed thermoplastic urethan (TPU) film and the second one being a mesh reinforced silicone cast into a 3D printed mold. The valve models were mounted into a pulsatile flow simulator, on which their hemodynamic performance before and after ring annuloplasty was evaluated by common flow measurements. Out of the presented approaches, the anisotropic mesh reinforced valve performed best, creating larger coaptation height and thereby enabling higher endsystolic pressures and significantly larger cardiac outputs.