A parametric study assessing Implicit Solver limits for a generic FEM Simulation of PTA without stent deployment.

Area of Science:

• Biomedical Engineering
• Computational Mechanics
• Medical Simulation

Background:

• Percutaneous Transluminal Angioplasty (PTA) is a common procedure to treat arterial stenosis.
• Numerical tools like Finite Element Models (FEM) can enhance PTA outcomes by predicting surgical results.
• Robustness of FEM simulations is critical for clinical translation.

Purpose of the Study:

• To investigate the robustness of a generic FEM for PTA procedures.
• To determine the influence of stenosis percentage, offset, and arterial caliber on simulation convergence.
• To establish the boundaries for reliable FEM simulations in PTA.

Main Methods:

• Developed a generic FEM of the PTA procedure.
• Modeled five arterial calibers by adjusting the inner diameter to wall thickness ratio.
• Tested forty different configurations varying stenosis percentage and offset under consistent settings.
• Analyzed simulation convergence and element deformation.

Main Results:

• Convergence issues arise for stenoses exceeding 65% blockage due to excessive element deformation.
• Increased stenosis offset negatively impacts simulation convergence.
• Simulations are less robust for small and large arterial calibers compared to intermediate ones.
• An implicit solver demonstrates robustness for stenoses below 50% in all calibers.
• Medium-caliber arteries show better robustness, converging for stenoses up to 60%.

Conclusions:

• FEM simulations of PTA are valuable for predicting permanent strain without stent deployment.
• The robustness of FEM solvers is dependent on stenosis severity, offset, and arterial size.
• Implicit solvers are robust for PTA simulations with stenoses <50% in all calibers and up to 60% in medium calibers.
• This study defines critical parameters for reliable FEM application in PTA planning.