ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Figure 3. On the left, alternating strain distribution map through the axially compressed (5%) ovrelapped
stents (double stents model) after deployment in a silicon tube. Red line demarcates the overlap region of
which two rings are shown; in the magnification areas higher strain regions are depicted. On the right the
correspondent constant-life diagram is shown (green), compared with the single stent without stiffening
released in the same tube (yellow).
Figure 4. On the left alternating strain distribution map through the axially compressed (5%) stent in the
overlapping configuration after deployment in a silicon tube. Red line demarcates the overlap region of
which two rings are shown; in the magnification areas higher strain regions are depicted. On the right the
correspondent constant-life diagram is shown (dark red), compared with the double stent model (green).
5. CONCLUSIONS
In this work the use of finite element method allowed us to investigate the fatigue
behavior of overlapped stent when subjected to cyclic axial compression. Based on
simulations it can be concluded that:
i) higher risk of fatigue failure is associated with the stent overlapping configuration
with an alternating strain concentration that affect the link in the region next to the
overlapped portion;
ii) our findings help to explain the high incidence of stent fracture located close to the
overlapping portion observed in various clinical trials;
iii) this study demonstrates the possibility of using a simplified model with a region
with double stiffness, significantly reducing computational time required for
simulations.