Percutaneous Transluminal Angioplasty (PTA) with stent is employed to treat the cardiovascular diseases in clinical to dilate stenotic arteries. There have been two types of stents (helical coil shape and traditional mesh shape) wildly used in angioplasty in the past few years. This research studied the biomechanical effects on the expansion behavior of these two different stents with balloon in the artery vessel. The commercial three-dimensional finite element method (FEM) based software was employed to perform all the computations in this study. Simulation results reveal that the pressure is delivered uniformly by the balloon, which leads the stenosed vessel to dilate. The dog bone effect is more obvious in the helical coil stent than the traditional mesh stent. The regions close to both ends of the stent exhibit large deformation and high shear stress values for both stent types. In the clinical practices, large deformation may cause stress concentration which leads to the damage of the vessel.
