Spiral Laminal Flow™ Technology in a Self-Expanding Nitinol Stent: Investigation on the Manufacturing Process

Abstract

Self-expanding Nitinol stents are the preferred treatment for atherosclerotic diseases in femoral arteries. However, adverse clinical outcomes are recorded and mostly attributed to altered flow dynamics caused by the device, which can lead to in-stent restenosis in 15% to 32% of stented segments within 9 to 15 months post-intervention. Spiral laminar flow (SLF) technology consists of a helical ridge on the inner surface of the device, which recovers the natural helical blood flow downstream and reduces flow disturbance and turbulence caused by stenting, thus preventing disease progression. This study presents the manufacturing process developed to obtain the SLF technology on self-expanding Nitinol devices, either laser-cut or braided, and addresses the optimal manufacturing parameters to ensure mechanical performance (radial strength, crush load resistance) and physical characteristics (phase transition temperature, surface finishing) appropriate for endovascular applications.