Ultrasound biomechanical indices in carotid artery disease: evaluation of shear modulus, circumferential stress, longitudinal stress, and stiffness index—a cross-sectional study

The biomechanical condition and properties of the arterial wall illustrate a crucial principle regarding the basis and development of arterial diseases. This study aimed to investigate indicators such as stiffness index (β), circumferential stress (CSmean), longitudinal stress (LSmean), and shear modulus (SMmean) alterations of the left common carotid artery in human individuals afflicted with atherosclerotic carotid artery disease, in order to determine the relationship among the mentioned indicators. The current study introduced methods for tracing simultaneous alterations in the lumen and inter-adventitial diameters, intima–media thickness, longitudinal movement, and velocity of the left common carotid artery (CCA). The mentioned parameters were measured in 136 male subjects, classified into four groups: control (n = 35), mild (n = 34), moderate (n = 34), and severe (n = 33) stenosis, in a cross-sectional design using B-mode and Doppler ultrasound systems. These basic parameters were used to calculate the mentioned biomechanical indicators. There was a significant increasing trend for the above-mentioned biomechanical indicators of the CCA from the control to the severe stenosis group (p < 0.05). In addition, the results of the present study illustrated a significant relationship between SMmean and β, CSmean, and LSmean in subjects with various degrees of stenosis (p < 0.05). We conclude that indicators such as SMmean, β, CSmean, and LSmean could be beneficial for assessing atherosclerotic human carotid arteries and may also provide important information for physicians regarding appropriate therapeutic strategies, including interventional examination, balloon angioplasty, stent deployment, graft replacement, and discrimination of vulnerable plaques from others.