Associate Professor & Vice director of Department of Science of Materials, University of Cantabria, Spain

Speech Title: Comparative study of the microstructure and mechanical properties of human, porcine and ovine mitral chordae tendineae
Abstract: The aim of the present research is to determine the microstructure and mechanical properties of human, porcine and ovine mitral chordae tendineae. The study on humans was carried out on marginal chords obtained from mitral valves, explanted at surgery, including functional and calcified and degenerative chords. The mechanical response of the human and animal chords was determined by means of quasi-static tensile tests. The material parameters that were obtained and analysed (the Young’s modulus, the secant modulus, the proportional limit stress, the ultimate strength, the strain at fracture and the density of energy stored up to maximum load) revealed noticeable differences in mechanical behaviour between the different groups of mitral chordae tendineae. The general aspects appreciated in the stress vs. strain curves were correlated with the collagen morphological evidences determined microscopically. Moreover, the mechanical response of functional human and animal chords was compared, in order to validate these ones as valid animal models. The microstructural analysis was based on inspection of the mitral chordae tendineae by means of scanning electron microscopy and X-ray microtomography. With these techniques, it was possible to determine the arrangement of the collagen bundles in the three families of chords available as well as to identify the relevant features of the fracture cross section after a tensile test.