NUMERICAL ANALYSIS OF BALLOON EXPANDABLE STENT DEPLOYMENT INSIDE A PATIENT-SPECIFIC STENOTIC CORONARY ARTERY TO INVESTIGATE THE INSTANT MECHANICAL BEHAVIORS

Abstract

The instant mechanical behaviors of stenotic coronary artery and deployed stents have significant impacts on percutaneous coronary intervention prognosis. However, they could not be obtained directly from the current examination techniques, which are commonly used in clinical practice. Thus, we intend to investigate the instantaneous mechanical behaviors of deployed stent and artery through virtually stenting technology based on a real clinical case in assessment of geometric and biomechanical characteristics. Method: Finite element analysis models, including rigid guide catheter, six-folded balloon with conical tip, crimped and bended stent, stenotic coronary artery with soft plaques, were simulated through virtual mechanical expansion and recoil procedure. The morphology changes of coronary lumen, strain and stress distribution of involved components at different stages and apposition of stent struts were analyzed. Results: Lumen in the stenotic region restored patency obviously at maximum expansion and had an elastic recoil about 13.5% later. The maximum principal stress distribution of artery walls and plaque was mainly concentrated in the stenotic segment with the peak value of 1.252[Formula: see text]MPa and 2.975[Formula: see text]MPa at max expansion, 0.713[Formula: see text]MPa and 1.25[Formula: see text]MPa after recoil, respectively. The higher von Mises stress and plastic equivalent strain of stent were present at the bended strut and inter-ring connectors with the peak value of 714.2[Formula: see text]MPa and 0.2385 at max expansion, 694[Formula: see text]MPa and 0.2276 after recoil. Slight malappositions were found in the proximal segment and struts distribution in the stenotic sites showed certain asymmetry. Conclusion: The instant mechanical behaviors of artery and stent could be evaluated through virtual stenting approach in assessment of geometric and biomechanical characteristics. This may contribute to choosing the best stenting schemes and predicting the clinical outcomes for a specific patient.