Most peripheral stents are bare metal scaffolds that hold a vessel open while leaving blood in direct contact with the artery wall through the stent's open cells. A covered stent, sometimes called a stent graft, adds a fabric or membrane layer over that metal frame, creating a sealed conduit that channels blood flow while physically separating it from the surrounding tissue. This distinction matters clinically: a covered stent in peripheral arteries is chosen for a different set of problems than a bare stent typically addresses.
What Problem Does a Covered Stent Solve?
Bare stents are generally used to hold open a narrowed or recently angioplastied artery and restore normal luminal flow. Covered stents are used when the goal is exclusion — sealing off a section of vessel wall entirely. This becomes necessary in situations such as an arterial perforation during angioplasty, a pseudoaneurysm, an arteriovenous fistula, or a heavily diseased, aneurysmal segment that needs to be lined rather than simply scaffolded. By creating a continuous barrier, the covered stent redirects blood through its own lumen and away from the compromised wall segment.
How Does ePTFE Covering Work?
Expanded polytetrafluoroethylene (ePTFE) is the most common covering material used in peripheral stent grafts. It is a biocompatible, microporous polymer that is thin, flexible, and resistant to kinking, allowing it to be bonded to a metal stent frame — typically nitinol for self-expanding designs — without significantly compromising the device's ability to track through tortuous vessels or conform once deployed. The ePTFE layer forms a low-porosity barrier that resists blood leakage while the metal scaffold provides the radial force needed to hold the graft open against the vessel wall.
Perforation Exclusion: A Key Bailout Use
Vessel perforation is an uncommon but serious complication of balloon angioplasty or atherectomy, particularly in calcified or heavily diseased peripheral arteries. When a perforation occurs, prolonged balloon inflation can sometimes control bleeding temporarily, but a covered stent is often the definitive endovascular solution: deployed across the perforation site, it seals the defect from within and restores a sealed flow channel, frequently avoiding the need for emergency open surgical repair. This bailout application is one of the most clinically important roles covered stents play in peripheral intervention.
Covered Stents vs Bare Stents: What Guides the Choice?
The decision between a covered and bare stent depends on the underlying pathology rather than a general preference for one technology. Bare stents preserve side-branch flow through their open cells and are generally the default choice for straightforward stenotic or occlusive lesions. Covered stents, by design, will occlude any side branches they cross, which is an important consideration in branch-rich territories. A qualified physician weighs lesion location, the presence of nearby collaterals or branches, and the specific indication — exclusion versus scaffolding — when selecting a device type.
INVAMED's Atlas Endovascular Stent Graft
INVAMED offers the Atlas Endovascular Peripheral Stent Graft as part of its peripheral arterial disease portfolio, alongside the company's bare self-expanding stent line. As a covered platform, it is designed to combine a metal scaffold with a graft covering intended for applications such as vessel exclusion in the peripheral arterial system. Full technical specifications should be confirmed directly through the Atlas Endovascular Peripheral Stent Graft product page, and clinicians should consult the Instructions for Use (IFU), since availability and specific indications vary by country. The broader peripheral arterial disease device category includes related bare stent and balloon technologies.
Durability Considerations for Covered Devices
Because the graft material adds a physical barrier, covered stents can behave somewhat differently over time compared with bare stents — for instance, in how they respond to compressive forces at the knee or groin, or in the pattern of any in-stent narrowing that develops. Manufacturer-reported specifications and long-term surveillance data for a given device should be reviewed by the treating team when covered stents are used outside straightforward bailout scenarios, such as in planned exclusion of femoropopliteal aneurysmal disease.
Are covered stents used only in emergencies?
No. While perforation exclusion during angioplasty is a well-recognized emergency use, covered stents are also used electively in planned situations such as excluding an aneurysmal arterial segment or treating a pseudoaneurysm. A qualified physician determines suitability based on the specific vascular pathology present.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.