A physical corrosion model for bioabsorbable metal stents

Area of Science:

• Biomaterials Engineering
• Computational Mechanics
• Cardiovascular Device Technology

Background:

• Absorbable metal stents (AMSs) represent an advancing frontier in cardiovascular disease treatment.
• Accurate computational modeling is essential for optimizing AMS design and performance.
• Existing models often lack the physical basis or geometric complexity to fully represent AMS corrosion.

Purpose of the Study:

• To develop a novel physical corrosion model for AMSs using the finite element method.
• To simulate the time-dependent, three-dimensional geometry changes of a corroding AMS.
• To investigate diffusion-controlled corrosion mechanisms in AMSs.

Main Methods:

• Implementation of a finite element method (FEM) with adaptive meshing to model AMS corrosion.
• Development of a physical corrosion model capturing surface evolution.
• Simulation of diffusion-controlled corrosion processes for a 3D AMS geometry.

Main Results:

• The model successfully captures the changing surface geometry of a 3D AMS during diffusion-controlled corrosion.
• Predictions of device geometry and mechanical performance were compared with existing phenomenological models.
• The influence of alloy solubility and diffusivity on AMS performance during corrosion was explored.

Conclusions:

• The developed physical corrosion model provides a more realistic simulation of AMS behavior than previous phenomenological approaches.
• This model enhances understanding of AMS degradation, facilitating improved design for cardiovascular applications.
• Further research can leverage this model to optimize AMS materials and predict long-term in vivo performance.