Bioinspired Heart Valve Prosthesis Made by Silicone Additive Manufacturing

Abstract

Here we present a multi-material additive manufacturing approach for fabricating personalized polymeric aortic heart valves and surrounding vasculature, derived from a patient's CT data. The valves feature geometries and fiber-reinforced leaflet architectures that resemble those of native valve tissue, along with materials that match the hardness and modulus of specific features. The designs are first simulated to predict the stresses and deformations in the valve, and subsequently the fabricated valves are tested in vitro to show excellent hydrodynamic properties.

Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis

“…19,20 The benefits of such an anisotropic microstructure is confirmed by a recent report of an anisotropic silicone valve, manufactured by additive manufacturing techniques. 21 The estimated number of patients per year requiring heart valve replacements by 2050 is >1 million. 22 Being inexpensive, while combining durability and biocompatibility, a novel PHV could benefit young and elderly patients globally with a one type-fit-all approach.…”

Transcatheter Aortic Valve Implantation Current Indications and Future Directions

“…Most recently, a glimpse into the future was provided from biomedical engineering with novel and innovative devices consisting of bio-polymeric heart valves. In-vitro testing has shown promising results (60)(61)(62)(63), and it remains to be seen if, and when the technology can be implemented in clinical studies.…”

Polymeric Heart Valves: Back to the Future?

“…Coulter et al have developed an impressive valve prototype that leverages a 3D-printing-based patientspecific crimpable polymer stent and suggests a promising bioinspired valve design that warrants further study. 11 The in vitro assessments are encouraging, but additional testing remains necessary, given the well-documented limitations of prior polymer valves.…”

“…Against this backdrop, Coulter et al 11 present their novel approach for multiaxis additive manufacturing of patientspecific silicone-based polymeric heart valves comprised of a multilayered silicone trileaflet valve mounted within a crimpable polymer mesh stent derived from computed tomography (CT) scan anatomy. Polymer-based prosthetic valves have been in existence for several decades and were indeed implanted in humans in the 1960s.…”

“…As prior silicone-based valves were limited by their durability, Coulter et al have attempted to address this issue with a bioinspired leaflet architecture featuring (1) two-layered valve leaflets with a medium-firmness (43A Shore) silicone mirroring the native ventricularis layer on the inflow surface and a firmer silicone (80A Shore) mirroring the native fibrosa layer on the aortic surface and (2) direct ink-written silicone reinforcement fibers in various patterns ranging from geometric to physiologic, the latter following that of the maximal leaflet stresses in the group's computational testing. 11 In the group's in vitro assessment with pulse duplicator testing, their polymer valves exceeded the Organization Internationale de Normalization (ISO 5840-3:2013) minimum standard for transcatheter valve prostheses with regard to effective orifice area (EROA) and regurgitant volume (RV). While the presented in vitro data are somewhat limited with regard to the testing methods, the authors report comparable EROA and RV numbers, though without statistical comparison, to those of similar commercially available transcatheter and surgical valves.…”