Textile for heart valve prostheses: Fabric long‐term durability testing

Abstract

The rapid developments and success in percutaneous vascular surgery over the last two decades with the now common stent grafts implantation, make the noninvasive surgery technique today attractive even for heart valve replacement. Less traumatic for the patient and also less time consuming, percutaneous heart valve replacement is however at its beginning and restricted to end of life patients. The noninvasive procedure expects from the heart valve prosthesis material to be resistant and adapted to folding requirements of the implantation process (catheter). Polyester fabric could be a suited material for heart valve implanted percutaneously. Highly flexible and resistant, polyester fabric proved to be well adapted to the dynamic behavior of a valve and polyester (Dacron) is also widely used for vascular grafts implantation and shows good biocompatibility and durability. However, today there's no data available on long-term durability of fabric used as heart valve material. The purpose of this work is to study the long term behavior of a microdenier polyester fabric construction under combined in vitro flexure and tension fatigue stress. In the novel in vitro testing technique presented, a fabric specimen was subjected to combined flexural and tensile fatigue generated by fluid flow under physiological pressure conditions. The results obtained show how flexural properties change with fatigue time, which reflects directly on the suitability of a fabric in such devices. It was also observed that these fabric structural changes directly influence the in vitro behavior of the textile heart valve prosthesis.

Transcatheter fiber heart valve: Effect of crimping on material performances

“…Heim et al showed that a textile polyester could be considered as an alternative solution to replace valve leaflets. [9][10][11][12] Textile is a discontinuous material obtained from the assembling of individual fibers. Moreover, polyester is a standard biomaterial that has been already used extensively in vascular implants (e.g., arterial and stent grafts).…”

Polymers in Cardiology

“…Additionally, it possessed enhanced resistance to calcification and thrombosis with superior in vivo biostability [20]. Furthermore, textile, less fragile polyester-based leaflets were designed as alternative to xenogenic, biologic materials [21,22]. Based on these examples can be stated that also synthetic, polymeric materials could be an alternative replacement for valve leaflets.…”

“…As recommended TAVI are established for the treatment of highrisk, multimorbid patients with severe aortic stenoses which are no candidates for the open-heart surgical replacement. Since it is known that biological valves based on xenogenic pericardium tend to calcify and have a decreased durability in comparison to mechanical valves [19] also valve materials based on synthetic polymers, such as polycarbonate urea urethanes and polyesters, are under consideration [20][21][22][23]. These examples demonstrate impressively that polymers became more important also for cardiological applications.…”

Need for new materials, biofunctionalization and non-surgical heart valve technology

“…These materials are expected to offer prolonged durability compared with that seen in current biological valves, and feature all the possible attributes of the ideal implant in blood flow (biocompatibility, fatigue resistance, elimination of the risk of valve apparatus fracture, resistance of immunitymediated processes, resistance to calcium deposition, and antithrombogenic surface). It would then be sufficient if the novel material possesses at least the properties identical to those seen in current components of mechanical valves [6,7] . Several materials that have shown promise to meet these requirements are currently available [8,9] .…”