The influence of heart valve geometry on long-term functionality

Heart valve tissue engineering

In in situ tissue-engineering of heart valves, a polymer valve is to be implanted in the patient, immediately taking over the native valve’s functionality. Following a host immune response, cells should populate the polymer valve and produce native tissue, while the polymer gradually degrades. Eventually, the polymer valve will be completely replaced by a native heart valve: the passive polymer implant has evolved into a native, living, heart valve that can last for a lifetime.

Valve geometry is essential for valve functionality

In order to make these valves fully functional after implantation, let alone for a lifetime, their design must be well-considered. Previous research has shown that the valve geometry plays a crucial role in ensuring valve functionality (Figure 1A, [1]). To provide a benchmark for our tissue-engineered heart valves, we recently established an extensive dataset of human native heart valves from fetal to adult origin [2]. In the current project, we aim to utilize the newly gained experimental knowledge to investigate the effect of valve geometry on important mechanical parameters, such as stresses and strains, which are indicators for long-term valve functionality.

Project outline: from experimental data to valve functionality predictions

A finite element framework is readily available in which the student can generate finite element meshes with different valve geometries by changing, for instance, the valve radius and height, and leaflet thickness and curvature. By performing finite element simulations, the influence of valve geometry on valvular mechanics and functionality can be assessed. Ultimately, this knowledge can be extrapolated to our tissue-engineered valves, to for example adapt their design to ensure long-term functionality. Basic knowledge of computer programming and continuum mechanics is highly recommended. Weekly meetings will be held together with students from related heart valve biomechanics projects, collaboration between these students is highly encouraged.

References
[1] Loerakker et al., Journal of Biomechanics 2013, vol. 46(11), pp. 1792-1800
[2] Oomen, P.J.A et al., Acta Biomater, vol. 29, 161–169