How plaque morphology and stenosis severity govern stent-artery interaction and deployment outcomes: a computational study.

Coronary atherosclerosis disrupts blood flow, and stent implantation is a common revascularization strategy for this condition. While stent design influences outcomes, lesion-specific characteristics, such as plaque morphology and stenosis severity, also play a critical role. This study, through finite element analysis (FEA), evaluated stent-artery interactions (SAI) across symmetric (SYM) and asymmetric (ASYM) plaques at 40%, 60%, and 80% stenosis severity. Six computational models were developed and stent performance evaluated using standard mechanical metrics including radial recoil (RR), dog-boning (DB), foreshortening (FS), longitudinal recoil (LR), and lumen gain (LG). At maximum expansion, peak stent stresses were similar between SYM and ASYM lesions at each severity level, increasing only slightly (8-9%) with stenosis severity. However, after recoil, morphology significantly altered stress distribution: SYM plaques concentrated stress in the stent's central region, while ASYM lesions shifted high stress toward the proximal and distal rings, particularly at crown apexes and ring junctions, known as fatigue-prone sites. Arterial stress patterns also changed significantly. The SYM stenosis led to uniform circumferential stresses, whereas ASYM plaques produced eccentric stress peaks adjacent to the narrowed wall. This localization of mechanical stress explains the elevated risk of vessel injury in eccentric lesions, despite comparable global stress levels. DB increased substantially with severity (10-15% at 40%; 30-35% at 80%), RR rose from 20 to 50%, FS remained low (1-4%), and LG was higher in asymmetric geometries. These findings demonstrate that stenosis severity determines stress magnitude, while plaque morphology dictates its spatial distribution, guiding potential failure sites and informing strategies for lesion-specific stent design. This study presents a comparison of SAI across different morphologies and highlights the importance of plaque-aware procedural planning. Although based on idealized geometries and homogeneous materials, this work establishes a foundation for future patient-specific simulations incorporating anatomical and tissue heterogeneity.