A vascular stent is a tubular implant providing radial support inside a blood vessel or vascular graft. Unlike a bypass graft, it supports the existing route. Support is a mechanical function; sustained patency is an outcome to measure.[ref]
Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems by the FDA. Section I, Intravascular Stent
A balloon-expandable vascular stent retains its enlarged shape after balloon deflation. A self-expanding vascular stent enlarges after release from its constrained delivery configuration, through material properties, geometry or both.[ref]
Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems by the FDA. Section I, Balloon Expandable Stent and Self-expanding Stent
Stent recoil gives a simple worked measurement. If bench imaging measures diameter during expansion and after balloon deflation, defineFor illustrative diameters and , recoil is about . The lumen area falls by about if both sections are circular, since area scales with diameter squared. Neither percentage alone predicts the change in pulsatile blood flow.
Bench radial-compression tests record diameter against external pressure. Loading and unloading distinguish reversible response from permanent damage; cycling probes mechanical fatigue. The FDA engineering guidance separately considers microscopy and durability tests. These measurements connect vascular stents to biomechanics and biomaterials; bench performance does not establish clinical effectiveness.[ref]
Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems by the FDA. Sections IV.B.4–6 and IV.B.9–11, recoil, integrity, radial response and durability
New to topics? Read the docs here!