Novel wavy surface design for enhanced frame anchoring performance in the exchangeable transcatheter aortic valve implantation procedure

Abstract

Laser powder bed fusion, LPBF, provides manufacturing advantages, not only for complex geometry, but also for small-scale surface features. In this study, the benefit of introducing a wavy feature on the surfaces of replacement heart valves has been explored. Specifically, a new concept in exchangeable valves aims to implant a holding frame into a diseased valve such that an exchangeable valve can be implanted into the holding frame but can then be removed and replaced by another exchangeable valve as and when the first valve deteriorates. In this proposed procedure, the anchoring force between the holding frame and valve frame could be too low to prevent the valve from displacing as blood is pumped through the heart. One way in which the anchoring force could be increased is by introducing a wavy profile on the contact surfaces between the frames. In this study, a flat representation of the two frames has been used to computationally investigate the effect of wavy surface profiles on the force required to displace one frame relative to the other. The so-called pull-out force was shown to be increased by between three and five times compared to smooth surface frames, using a wave amplitude of 0.1 mm and wavelengths varying between 0.25 and 0.50 mm.