Stent modeling using immersed finite element method

The objective of this paper is to study the mechanical behaviors of angioplasty stents during and after implantation using a fluid–structure interaction computational technique. The deployment of a balloon expandable stent is simulated using immersed finite element method (IFEM), which was developed for solving complex fluid and deformable structure interaction problems. Using this method, we modelled a stainless steel stent in a blood vessel. A balloon is deployed to assist the expansion of the stent that is to be plastically deformed. The balloon is modelled as a thin hyperelastic material while the stent has the property of steel. The mechanical behaviors such as the expansion mechanism, stress distribution on the stent, and the surrounding fluid velocity profile during the implantation of the stent are studied. With appropriate applied internal pressure, the balloon inside the stent is deployed which linearly expands the diameter of a Medtronic AVE Modular Stent S7 until it reaches 1.7 times of its original diameter. The results will assist in the development of novel stent designs and stent deployment protocols to minimize vascular injury during stenting and reduce restenosis.