Finite Element Modeling and Experimental Validation of a z-Type
Self-Expanding Endovascular Stent
Abstract
Stent migration due to haemodynamic drag remains the primary cause of
type I endoleak, potentially leading to aneurysm rupture. The prevalence
of migration and endoleak can be partially attributed to deficiencies in
stent-graft radial spring design and a lack in understanding of the
mechanical properties of endovascular stents. A converged finite element
model of a custom radial extensometer was developed, fit, and validated
using experimental results for bare stent wire (”uncovered”) with
outer diameter of 12 mm stent. During stent constriction to 50 % of the
original cross- sectional area, a comparison of experimental and modeled
results produced an r2 value of 0.946, a standard error of 0.099 N, and
a mean percent error of 1.69 %. This validated finite element model can
be used to analyze the mechanisms responsible for radial force
generation in 316L stainless steel self-expanding endovascular stents,
as well as to evaluate new stent designs.