Ecole Nationale Supérieure des Mines, Saint-Etienne, France.
J Endovasc Ther. 2013 Aug;20(4):523-35. doi: 10.1583/12-4063.1.
To assess numerically the flexibility and mechanical stresses undergone by stents and fabric of currently manufactured stent-grafts.
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.
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%).
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.
数值评估目前制造的支架移植物的支架和织物的柔韧性和机械应力。
使用有限元分析对 8 种市售的支架移植物（Aorfix、Anaconda、Endurant、Excluder、Talent、Zenith Flex、Zenith LP 和 Zenith Spiral-Z）进行建模。对支架移植物进行了结合弯曲至 180°和支架移植物加压至 150mmHg 的数值基准测试。通过计算管腔缩小率、支架中的最大应力和织物中的最大应变来评估支架移植物的柔韧性。
除 Talent 支架移植物外，在 90°时的管腔缩小率<20%。在 180°时，Z 型支架模型（Talent、Endurant、Zenith 和 Zenith LP；范围 39%-78%）的管腔缩小率高于螺旋型（Aorfix、Excluder 和 Zenith Spiral-Z）或圆形支架型（Anaconda）移植物（范围 14%-26%）。在 180°时，Z 型支架移植物的最大应力较高（范围 370-622MPa），而螺旋型或圆形支架移植物的最大应力较低（范围 177-368MPa）。在 90°和 180°时，聚酯支架移植物的织物应变较低，且彼此之间差异不显著（范围 0.5%-7%），而 Excluder 支架移植物的膨体聚四氟乙烯织物的应变较高（范围 11%-18%）。
支架设计强烈影响主动脉支架移植物的机械性能。与 Z 型支架相比，螺旋型和圆形支架提供更大的柔韧性和更低的应力值，因此具有更好的耐久性。
