Finite Element Analysis of the Mechanical Performances of 8 Marketed Aortic Stent-Grafts. (August 2013)

• Record Type: Journal Article
• Authors: Demanget, Nicolas; Duprey, Ambroise; Badel, Pierre; Orgéas, Laurent; Avril, Stéphane; Geindreau, Christian; Albertini, Jean-Noël; Favre, Jean-Pierre
• Is Part Of: Journal of endovascular therapy. Volume 20:Number 4(2013)
• Page Start: 523
• Page End: 535
• Publication Date: 2013-08
• Subjects: aortic stent-graft -- finite element analysis -- aortic aneurysm -- mechanical behavior -- polyethylene terephthalate -- polyester -- Dacron -- polytetrafluoroethylene -- nitinol -- 316L stainless steel -- stress -- strain -- stent design -- spiral stent -- circular stent -- Z-stent; Blood-vessels -- Endoscopic surgery -- Periodicals; Angioscopy -- Periodicals; Intravenous catheterization -- Periodicals; Peripheral vascular diseases -- Treatment -- Periodicals; Vascular Surgical Procedures -- Periodicals; Angioscopy -- Periodicals; Catheterization, Peripheral -- Periodicals; Peripheral Vascular Diseases -- therapy -- Periodicals; Angioscopie; Maladies vasculaires périphériques; 617.413
• DOI: 10.1583/12-4063.1
• Languages: English
• ISSNs: 1526-6028

Abstract

Purpose: To assess numerically the flexibility and mechanical stresses undergone by stents and fabric of currently manufactured stent-grafts. Methods: Eight marketed stent-graft limbs (Aorfix, Anaconda, Endurant, Excluder, Talent, Zenith Flex, Zenith LP, and Zenith Spiral-Z) were modeled using finite element analysis. A numerical benchmark combining bending up to 180° and pressurization at 150 mmHg of the stent-grafts was performed. Stent-graft flexibility, assessed by the calculation of the luminal reduction rate, maximal stresses in stents, and maximal strains in fabric were assessed. Results: The luminal reduction rate at 90° was <20% except for the Talent stent-graft. The rate at 180° was higher for Z-stented models (Talent, Endurant, Zenith, and Zenith LP; range 39%–78%) than spiral (Aorfix, Excluder, and Zenith Spiral-Z) or circular-stented (Anaconda) devices (range 14%–26%). At 180°, maximal stress was higher for Z-stented stent-grafts (range 370–622 MPa) than spiral or circular-stented endografts (range 177–368 MPa). At 90° and 180°, strains in fabric were low and did not differ significantly among the polyester stent-grafts (range 0.5%–7%), while the expanded polytetrafluoroethylene fabric of the Excluder stent-graft underwent higher strains (range 11%–18%). Conclusion: Stent design strongly influences mechanical performances of aortic stent-grafts. Spiral and circular stents provide greater flexibility, as well as lower stress values than Z-stents, and thus better durability.