Transcatheter fiber heart valve: Effect of crimping on material performances

Transcatheter aortic valve implantation (TAVI) has become a popular alternative technique to surgical valve replacement. However, the biological valve tissue used in these devices appears to be fragile material in the long term particularly due being folded for low diameter catheter insertion purposes and when released in a calcified environment with irregular geometry. Textile polyester material is characterized by outstanding folding and strength properties combined with proven biocompatibility. It could therefore be considered as a replacement for biological valve leaflets in the TAVI procedure. The folding process associated with crimping, however, may degrade the filaments involved in the fibrous assembly and limit the durability of the device. The purpose of the present work is to study the effect of different crimping conditions on the mechanical performances of textile valve prototypes made from various fabric constructions. Results show that crimping generates some creases in the fabrics, which surface topography varies with fabric construction and crimping configuration. The mechanical properties of the crimped materials are globally slightly reduced. To determine how critical the modifications due to crimping are for prosthesis durability, more detailed long term in vitro and in vivo trials with crimped textile prototypes are needed in addition to this preliminary work.