A coupled stent-balloon finite element model successfully demonstrated the expected nonuniform deformation of helical stents, whereas displacement-controlled and uniform expansion methods did not.
A coupled stent-balloon finite element model accurately demonstrates nonuniform deformation in helical stents, and a progressive expansion approach can mitigate this issue to minimize potential arterial damage.
Helical polymeric stents have been proposed as a suitable geometry for biodegradable drug-eluting polymer-based stents. However, helical stents often experience nonuniform local expansion (dog boning), which can prohibit full stent expansion using conventional methods. The development of stents and deployment methods is challenging and can be supported by numerical analysis; however, this complex problem is often approached with simplified boundary conditions that may not be appropriate for helical stents. The finite element method (explicit and implicit) was used to investigate three common stent expansion approaches with a focus on helical stent geometry, which differs from traditional wire mesh stent expansion. Although each of the three methods considered provided some insight into the expansion characteristics, common displacement controlled, and uniform expansion methods were not able to demonstrate the characteristic local deformations observed in expansion. A coupled stent-balloon model, although computationally expensive, was able to demonstrate the expected nonuniform deformation. To address nonuniform expansion, a progressive expansion approach has been investigated and verified numerically. This method may also provide a suitable solution for nonuniform expansion in other stent designs by minimizing loading and potential damage to the artery that can occur during stent deployment.
Paryab et al. (Wed,) conducted a other in Helical stent expansion. Coupled stent-balloon finite element model vs. Displacement controlled and uniform expansion methods was evaluated on Demonstration of characteristic local deformations (dog boning). A coupled stent-balloon finite element model successfully demonstrated the expected nonuniform deformation of helical stents, whereas displacement-controlled and uniform expansion methods did not.