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

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Computational Mechanics

Background:

• Coronary atherosclerosis necessitates stent implantation for revascularization.
• Stent design and lesion characteristics critically affect procedural outcomes.
• Understanding stent-artery interactions (SAI) is key for optimizing treatment.

Purpose of the Study:

• To evaluate SAI using finite element analysis (FEA) across varying plaque morphologies (symmetric vs. asymmetric) and stenosis severities (40%, 60%, 80%).
• To compare mechanical performance metrics of stents under different lesion conditions.
• To elucidate the influence of plaque morphology on stress distribution and potential failure sites.

Main Methods:

• Developed six computational models simulating stent deployment in symmetric (SYM) and asymmetric (ASYM) plaques.
• Employed FEA to analyze SAI and evaluate mechanical metrics: radial recoil (RR), dog-boning (DB), foreshortening (FS), longitudinal recoil (LR), and lumen gain (LG).
• Assessed peak stent stresses and arterial stress patterns at maximum expansion and after recoil.

Main Results:

• Stenosis severity primarily determined peak stress magnitude, while plaque morphology dictated stress distribution.
• ASYM plaques shifted high stress to fatigue-prone stent regions (crown apexes, ring junctions).
• ASYM lesions resulted in eccentric arterial stresses and higher lumen gain compared to SYM plaques.

Conclusions:

• Plaque morphology significantly alters stress distribution, influencing potential stent failure and vessel injury, even with similar global stress levels.
• Findings emphasize the importance of considering plaque characteristics for lesion-specific stent design and procedural planning.
• This FEA study provides a foundation for patient-specific simulations incorporating anatomical and tissue heterogeneity.