Testing Different Hypotheses of Vascular Homeostasis Based on Mechanical Stress or Strain in Image-Based Models Using an Inverse Method

Various hypotheses are previously suggested to describe the tendency of vascular tissue to adapt in response to alterations in mechanical stimuli. It is still a matter of controversy which mechanical quantity governs or correlates well with the adaptation, contributing to the mechanical homeostasis. A computational tool that can distinguish between different hypotheses under various physiological conditions may help better understanding of the governing rules. Recently, an inverse optimization method has been developed to estimate the optimal spatial distributions of arterial wall thickness and material anisotropy of image-based models while satisfying a homeostatic condition assumed [1]. The same numerical method can be utilized to investigate the consequent optimal structures resulting from different hypotheses for the mechanical homeostasis. We consider three hypotheses for a homeostatic state based on intramural stress or cyclic stretch and examine their effects on the optimized distributions of thickness and anisotropy. The results show the capability of the presented method in discriminating different hypotheses of vascular homeostasis with image-based models, the validity of which requires more experimental data.