Finite element modeling of a novel self-expanding endovascular stent method in treatment of aortic aneurysms.

A novel large self-expanding endovascular stent was designed with strut thickness of 70 μm × 70 μm width. The method was developed and investigated to identify a novel simpler technique in aortic aneurysm therapy. Stage 1 analysis was performed after deploying it in a virtual aneurysm model of 6 cm wide × 6 cm long fusiform hyper-elastic anisotropic design. At cell width of 9 mm, there was no buckling or migration of the stent at 180 Hg. Radial force of the stents was estimated after parametric variations. In stage 2 analysis, a prototype 300 μm × 150 μm stent with a cell width of 9 mm was chosen, and it was evaluated similarly after embedding in the aortic wall, and also with a tissue overgrowth of 1 mm over the stent. The 300/150 μm stent reduced the peak wall stress by 70% in the aneurysm and 50% reduction in compliance after embedding. Stage 3 analysis was performed to study the efficacy of stents with struts (thickness/width) 70/70, 180/100 and 300/150 μm after embedding and tissue overgrowth. The adjacent wall stresses were very minimal in stents with 180/100 and 70/70 μm struts after embedding. There is potential for a novel stent method in aortic aneurysm therapy.