Why does the choice of graft fabric matter as much as the metal frame in an aortic stent graft? Because the fabric is what actually creates the seal between arterial blood and the weakened aneurysm wall — the metal scaffold simply holds it in the right shape and position. Expanded polytetrafluoroethylene, universally shortened to ePTFE, is one of the most established graft fabric materials used in vascular devices, and it plays exactly this sealing role in aortic stent grafts such as INVAMED's Atlas Aortic Stent Graft. Understanding what ePTFE is, and why it has remained a mainstay material in vascular engineering for decades, explains a lot about how modern stent grafts function.
What Is ePTFE and Why Is It Used in Vascular Grafts?
ePTFE is a fluoropolymer material produced by expanding solid PTFE — the same base polymer family associated with the well-known "Teflon" name — into a microporous membrane structure. This expansion process creates a material with a fine node-and-fibril microstructure, giving it mechanical strength, flexibility, and a track record of use in vascular applications extending back many years. As a graft fabric, ePTFE is generally valued for being smooth on its blood-contacting surface, resistant to degradation over long implantation periods, and capable of being manufactured into thin, conformable sheets or tubes suitable for use on a stent scaffold. These general material properties are well established in vascular graft literature broadly, independent of any single manufacturer's specific device.
How Does ePTFE Work Together With a Nitinol Scaffold?
A graft fabric alone has no inherent shape memory or radial strength — it needs a supporting scaffold to hold it open against the vessel wall and maintain lumen patency over time. This is where nitinol, a nickel-titanium alloy known for its shape-memory and self-expanding properties, comes in. INVAMED's Atlas Aortic Stent Graft is built around a nitinol scaffold with an ePTFE (or PTFE) graft covering bonded to it, combining the scaffold's mechanical support and self-expanding or balloon-expandable behavior with the fabric's sealing function. The two materials are engineered to work as a single system: the nitinol frame provides the structural force and shape, while the ePTFE covering provides the impermeable barrier that prevents arterial pressure from reaching the aneurysm sac.
What Does Biocompatibility Mean for a Long-Term Implant?
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.
Why Does Material Choice Matter to the Overall Repair Outcome?
The graft fabric is ultimately what determines whether the aneurysm sac stays excluded from arterial pressure over the long term. A material that resists wear, maintains its seal, and integrates acceptably with surrounding tissue supports the fundamental goal of aortic stent grafting: preventing aneurysm sac pressurization while maintaining a patent conduit for blood flow. Material performance works alongside — not instead of — sound fixation and correct sizing, all of which are assessed together during physician planning and confirmed through follow-up imaging after implantation. General background on this repair category is available on INVAMED's aortic aneurysm and dissection repair page.
How long has ePTFE been used in vascular medicine?
ePTFE has a well-established history in vascular surgery spanning several decades, including use in surgical bypass grafts prior to the development of endovascular stent grafts, which reflects a long track record supporting its continued use as a graft fabric material in current aortic devices.