Recent clinical studies of the percutaneous transvenous
mitral annuloplasty (
PTMA) devices have shown a short-term reduction of
mitral regurgitation after implantation. However, adverse events associated with the devices such as compression and perforation of vessel branches, device migration and fracture were reported. In this study, a finite
element analysis was carried out to investigate the biomechanical interaction between the proximal anchor
stent of a
PTMA device and the coronary sinus (CS) vessel in three steps including: (i) the
stent release and contact with the CS wall, (ii) the axial pull t the
stent connector and (iii) the pressure inflation of the vessel wall. To investigate the impact of the material properties of tissues and
stents on the interactive responses, the CS vessel was modelled with human and porcine material properties, and the proximal
stent was modelled with two different
Nitinol materials with one being stiffer than the other. The results indicated that the vessel wall stresses and contact forces imposed by the
stents were much higher in the human model than the porcine model. However, the mechanical differences induced by the two
stent types were relatively small. The softer
stent exhibited a better
fatigue safety factor when deployed in the human model than in the porcine model. These results underscored the importance of the CS tissue mechanical properties. Vessel wall stress and
stent radial force obtained in the human model were higher than those obtained in the porcine model, which also brought up questions as to the validity of using the porcine model to assess device mechanical function. The quantification of these biomechanical interactions can offer scientific insight into the development and optimisation of the
PTMA device design.