Investigating the Impact of Atherosclerotic Plaque Size on Human Arterial Wall Stress-Strain Hysteresis Loop and Deformed State Pattern

Atherosclerosis remains the leading cause of death worldwide, characterized by chronic inflammatory arterial disease and the formation of plaques that narrow arteries and obstruct blood flow. Mathematical and computer models of arteries with plaque provide insight into the progression of the disease and help in the development of treatments, particularly in cardiovascular surgery and stent development. This study uses direct computer modeling to analyze the deformation of human arteries affected by atherosclerotic plaque as a function of plaque size. The finite element method (FEM) was used to derive the distribution of strains and stresses over time. The model considers two arterial wall layers with different mechanical properties and explicitly models an atherosclerotic plaque. The viscoelastic effects were considered using the Prony series, which considers the tissue’s deformation over time. The geometric modeling allows for a change in the size of the plaque, affecting the stress structure similar to pulse waves. The results show a significant concentration of stresses above the lateral edges of the plaque, with the layer adjacent to the lipid core undergoing compression. The maximum stresses increase nonlinearly with plaque size, indicating a critical point. Strain analysis reveals an oscillatory behavior that lags behind the stresses due to viscoelasticity. Gradual plaque enlargement under constant load leads to an increase in stresses and strains, highlighting potential complications. These results emphasize the influence of plaque size on blood pressure distribution. Understanding the relationship between stress and strain opens up opportunities for personalized treatment planning and stent design optimization, ultimately improving patient outcomes.