Evaluation of spatial distribution and characterization of wall shear stress in carotid sinus based on two-dimensional color Doppler imaging

Atherosclerosis risk assessment in human carotid artery with variation in sinus length: a numerical approach

The mortality rates due to cardiovascular diseases are on a rise globally. One of the major cardiovascular diseases is stroke which occurs due to atherosclerotic plaques build-up in the carotid artery. The common carotid artery (CCA) bifurcates into the internal carotid artery (ICA) and external carotid artery (ECA). Sinus present at ICA is an ellipsoidal-shaped dilated region acting as a pressure receptor and blood flow regulator. Dimensions of the sinus vary from person to person, affecting the hemodynamics of the carotid artery. The current numerical study manifests a 3D flow analysis by varying the sinus length to investigate its local and global effects on the hemodynamics of the carotid artery using various biomechanical risk analysis parameters of atherosclerosis. User-defined function (UDF) dictates the pulsatile flow velocity profile imposed at the inlet. Near the outer wall (OW) of the sinus, the blood flow velocities are lower and recirculation zones are more. Though the recirculation zones for shorter sinus will be close to the inner wall (IW), interestingly, with an increase in the sinus length, the recirculation zones shift toward the OW with higher strength. These significantly decrease the x-wall shear stress (x-WSS) and time-averaged wall shear stress (TAWSS) values on the OW of the longer sinus. The other risk analysis parameters, like oscillatory shear index (OSI) and relative residence time (RRT), support the described consequences. These results reveal that sinus of increased length is more prone to developing atherosclerotic plaque.

Characteristics and evaluation of atherosclerotic plaques: an overview of state-of-the-art techniques

Atherosclerosis is an important cause of cerebrovascular and cardiovascular disease (CVD). Lipid infiltration, inflammation, and altered vascular stress are the critical mechanisms that cause atherosclerotic plaque formation. The hallmarks of the progression of atherosclerosis include plaque ulceration, rupture, neovascularization, and intraplaque hemorrhage, all of which are closely associated with the occurrence of CVD. Assessing the severity of atherosclerosis and plaque vulnerability is crucial for the prevention and treatment of CVD. Integrating imaging techniques for evaluating the characteristics of atherosclerotic plaques with computer simulations yields insights into plaque inflammation levels, spatial morphology, and intravascular stress distribution, resulting in a more realistic and accurate estimation of plaque state. Here, we review the characteristics and advancing techniques used to analyze intracranial and extracranial atherosclerotic plaques to provide a comprehensive understanding of atheroma.

Wall Shear Stress Alteration: a Local Risk Factor of Atherosclerosis

PURPOSE OF REVIEW

Wall shear stress describes the mechanical influence of blood flow on the arterial wall. In this review, we discuss the role of the wall shear stress in the development of atherosclerosis and its complications.

RECENT FINDINGS

Areas with chronically low, oscillating wall shear stress are most prone to plaque development and include outer bifurcation walls and inner walls of arches. In some diseases, patients have lower wall shear stress even in straight arterial segments; also, these findings were associated with atherosclerosis. High wall shear stress develops in the distal part (shoulder) of a stenosis and contributes to plaque destabilization. Wall shear stress changes are involved in the development of atherosclerosis. They are not fully understood yet and act in concert with tangential wall stress.

The Rheology of the Carotid Sinus: A Path Toward Bioinspired Intervention

The association between blood viscosity and pathological conditions involving a number of organ systems is well known. However, how the body measures and maintains appropriate blood viscosity is not well-described. The literature endorsing the function of the carotid sinus as a site of baroreception can be traced back to some of the earliest descriptions of digital pressure on the neck producing a drop in blood delivery to the brain. For the last 30 years, improved computational fluid dynamic (CFD) simulations of blood flow within the carotid sinus have demonstrated a more nuanced understanding of the changes in the region as it relates to changes in conventional metrics of cardiovascular function, including blood pressure. We suggest that the unique flow patterns within the carotid sinus may make it an ideal site to transduce flow data that can, in turn, enable real-time measurement of blood viscosity. The recent characterization of the PIEZO receptor family in the sinus vessel wall may provide a biological basis for this characterization. When coupled with other biomarkers of cardiovascular performance and descriptions of the blood rheology unique to the sinus region, this represents a novel venue for bioinspired design that may enable end-users to manipulate and optimize blood flow.

Biomechanical Forces and Atherosclerosis: From Mechanism to Diagnosis and Treatment

The article provides an overview of current views on the role of biomechanical forces in the pathogenesis of atherosclerosis. The importance of biomechanical forces in maintaining vascular homeostasis is considered. We provide descriptions of mechanosensing and mechanotransduction. The roles of wall shear stress and circumferential wall stress in the initiation, progression and destabilization of atherosclerotic plaque are described. The data on the possibilities of assessing biomechanical factors in clinical practice and the clinical significance of this approach are presented. The article concludes with a discussion on current therapeutic approaches based on the modulation of biomechanical forces.