Mechanical analysis on treatment of vertebral artery stenosis by stents with different links / 医用生物力学

Objective To investigate the mechanical effect of stents with different links on the treatment of vertebral artery stenosis, and provide scientific guidelines for the design of stent structure and clinical procedure of stenting intervention. Methods Models of three kinds of stents with different types of links (namely, L-stent, V-stent and S-stent according to the shape of links) and vertebral artery with stenosis were established by using Pro/Engineering, then the same boundary conditions were exerted on the three models to simulate the stent deployed in the vertebral artery by finite element analysis using ABAQUS. Results Compared with L-stent and V-stent, S-stent had a better compliance, generating smaller stress in the arterial wall, causing relatively weak vascular straightening. Due to smaller stress and axial shortening generated in the stent strut, S-stent made less lesion on the arterial wall. Conclusions The therapeutic effect of S-stent is the best among the three kinds of stents, which could reduce in-stent-restenosis, and has good prospect in clinical application.

Hemodynamic simulation of vertebral artery stenosis treated by stents with different links / 医用生物力学

Objective To investigate the hemodynamic effect of stents with different types of links on treating vertebral artery stenosis, and provide scientific guidelines for the design of stent structure and the clinical procedure of stent intervention. Methods Models of vertebral artery with stenosis and three kinds of stents with different types of links (named as L-stent, V-stent and S-stentaccording to the shapes) were constructed by using Pro/Engineering. The expansions of these stents in the stenotic vertebral artery were simulated using ABAQUS, and three finite element models of the stented vertebral artery were then established for fluid flow analysis, and hemodynamic simulation was performed using ANSYS-CFX. Results Compared with V-link and S-link stent, L-link stent had smaller area of low wall shear stress distributions and smaller blood stagnation area. Conclusions With better hemodynamic effect, L-stent can potentially reduce the possibility of in-stent restenosis and provide scientific references for the choice of stent, the design of stent structure and surgical planning of stent intervention.

Research progress in biomechanics of in-stent restenosis / 医用生物力学

Stent intervention has become one of the most effective ways in treating cardiac and cerebral vascular stenosis. However, postoperative in-stent restenosis remains a major unsettled issue. The occurrence of in-stent restenosis is related not only to the mismatch between stent and artery, as well as the stress induced by mechanical support of the stent struts on arterial wall, but also to the intimal hyperplasia induced by the hemodynamic change. Recent literatures on biomechanics of the stented artery were reviewed in this paper. In particular, from the view of solid mechanics and hemodynamics, the research progress of stented artery in biomechanical simulation was given detailed discussion; moreover, the biomechanical factors associated with in-stent restenosis were analyzed and summarized. Numerical simulation is a good method for investigating the relationship between stent intervention and in-stent restenosis, and it also provides a scientific guideline for the design of stent structure and clinical procedure of stent intervention.