Structure Interaction model of a polymeric aortic valve: comparison with experimental results and simulation in a patient-specific aortic root

The function of native heart valves, when not functioning, can be replicated by heart valve prostheses. Excellent candidate to mimic the structural and fluid dynamic behaviour of the native valves are bio-inspired polymeric heart valves (PHVs). A new PHV made of a styrenic block copolymer [1] has been considered in this work (Fig. 1). PHVs exploit the extremely thin leaflets to hamper flow as little as possible when opened, but also prevent blood back-flow when in closing position, when the leaflets are in mutual contact and a large transvalvular pressure gradient occurs. To investigate the haemodynamics of a PHV, a fluid–structure interaction (FSI) model was developed. Indeed, FSI models have been increasingly used in biomedical engineering applications and one of the most challenging fluid–structure problems in the human body involves the dynamics of heart valves. The aim of this study is to investigate the haemodynamic and structural behaviour of a PHV when implanted in the aortic position. The mechanical properties of the polymer were determined experimentally [2], while suitable FSI boundary conditions were set to simulate the physiological pressure load and pulsatile flow rate conditions obtained in a test bench. Numerical results are compared to experimental ones in terms of valve kinematics, bringing additional information like stress distribution and velocity patterns. Application of the FSI methodology to a patient-specific case is also briefly outlined.