The influence of aortic stiffness on carotid stiffness: computational simulations using a human aorta carotid model

Increased aortic and carotid stiffness are independent predictors of adverse cardiovascular events. Arterial stiffness is not uniform across the arterial tree and its accurate assessment is challenging. The complex interactions and influence of aortic stiffness on carotid stiffness have not been investigated. The aim of this study was to evaluate the effect of aortic stiffness on carotid stiffness under physiological pressure conditions. A realistic patient-specific geometry was used based on magnetic resonance images obtained from the OsiriX library. The luminal aortic-carotid model was reconstructed from magnetic resonance images using 3D Slicer. A series of aortic stiffness simulations were performed at different regional aortic areas (levels). By applying variable Young's modulus to the aortic wall under two pulse pressure conditions, one could examine the deformation, compliance and von Mises stress between the aorta and carotid arteries. An increase of Young's modulus in an aortic area resulted in a notable difference in the mechanical properties of the aortic tree. Regional deformation, compliance and von Mises stress changes across the aorta and carotid arteries were noted with an increase of the aortic Young's modulus. Our results indicate that increased carotid stiffness may be associated with increased aortic stiffness. Large-scale clinical validation is warranted to examine the influence of aortic stiffness on carotid stiffness.