Design and mechanical behaviors of sutureless prototype composite nitinol stent-grafts

Abstract

The stent-graft has always been a key device in endovascular treatments. However, most stents are integrated with graft by sutures, which may fracture or untie, leading to implant failure. This study reports a new sutureless composite stent-graft fabricated by braiding technology, which can combine various materials. The proposed sutureless braided stent-graft was constructed by incorporating bare/covered nitinol (NiTi) yarns into a polyethylene terephthalate multifilament at specific distributions. This technique generates a structure with alternately arranged metal and polymeric sections that equip the stent-graft with structural support and flexibility, respectively. The results showed significantly improved biomechanical performance (radial compression, bending and torsion resistance) of the stent-graft with covered NiTi yarns compared to bare NiTi yarns. This research presents important clinical implications in stent-graft manufacture and provides further study with an innovative stent-graft design.