Fiber heart valve prosthesis: Early in vitro fatigue results.

Transcatheter aortic valve replacement has become today a largely considered alternative technique to surgical valve replacement in patients with high risk for open chest surgery. Biological valve tissue used in the transcatheter devices has shown success over 5 years now, but the procedure remains expensive. Moreover, different studies point out potential degradations that the tissue can undergo when folded to lower diameter and released in calcified environment with irregular geometry, which may jeopardize the durability of the device. The use of synthetic materials, like textile in particular, to replace biological valve leaflets would help reducing the procedure costs, and limit the degradations when the valve is crimped. Textile polyester material has been extensively used in the vascular surgery and is characterized by outstanding folding and strength properties combined with proven biocompatibility. However, the friction effects that occur between filaments and between yarns within a fabric under flexure loading could be critical for the resistance of the material on the long term. The purpose of this study was to assess the early fatigue performances of textile valve prototypes under accelerated cyclic loading up to 200 Mio cycles. Durability tests show that the fibrous material undergoes rearrangements between fibrous elements within the textile construction and the mechanical properties are modified on the long term. But testing is not complete with 200 Mio cycles. The material should be tested up to a higher number of cycles in future work to test the effective long-term durability.