Numerical studies on fluid-structure interactions of stent deployment and stented arteries

This study is to investigate the mechanical behaviors of angioplasty stents during and after implantation and blood flow in the stented artery using the immersed finite element method. In this study, the mechanical behaviors such as the expansion mechanism, stress distribution on the stent during the implantation, and stent responses toward various vascular conditions are analyzed. Furthermore, pulsatile blood flow in stented artery is also examined to identify potential regions where the blood clots form and potentially induce reactions leading to thrombus formation. We found that the wall shear stress and the residence time are the highest at the entrance and the exit of the stent while they decrease significantly in between stent struts. The results suggested that platelets/particles are most likely to be activated near the entrance; they form aggregates in between struts where the shear stress is very low and eventually reside at the end of the stent where the resident time is the highest. Our numerical observations agree quite well with in vitro experimental studies. This analysis will assist in the development of novel stent designs and stent deployment protocols to minimize vascular injury during stenting and reduce restenosis.