Problem statement: Atherogenesis is affected by hemodynamic parameters, such as wall shear stress and wall shear stress spatial gradient. These parameters are largely dependent on the geometry of arterial tree. Arterial bifurcations contain significant flow disturbances. Approach: The effects of branch angle and vessel diameter ratio at the bifurcations on the wall shear stress distribution in ...

INTRODUCTION Enlargement of a pre-existing intracranial aneurysm is a well-established risk factor of rupture. Excessive low wall shear stress concomitant with turbulent flow in the dome of an aneurysm may contribute to progression and rupture. However, how stress conditions regulate enlargement of a pre-existing aneurysm remains to be elucidated. RESULTS Wall shear stress was calculated with...

BACKGROUND Wall shear stress is thought to play a critical role in the local development of atherosclerotic plaque and to affect plaque vulnerability. However, current models and hypotheses do not fully explain the link between wall shear stress and local plaque development. We aimed to investigate the relation between wall shear stress and local plaque development in surgically induced common ...

INTRODUCTION AND OBJECTIVES Local factors may influence neointimal proliferation following conventional stent implantation. In this study, the relationship between wall shear stress and luminal loss after coronary stenting was assessed using a combination of angiography, intravascular ultrasound, and computational fluid dynamics. PATIENTS AND METHOD Seven patients with de novo right coronary ...

BACKGROUND AND PURPOSE Posterior communicating artery aneurysms with oculomotor nerve palsy may imply sudden enlargement of the aneurysm sac and have a high risk of rupture. Our aim was to identify the morphologic and hemodynamic parameters in this special period of aneurysm progression and to assess related rupture risk indices. MATERIALS AND METHODS We analyzed the morphologic and hemodynam...

Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-averaged Reynolds numbers 50< or =Re(m)< or =300, corresponding to a range of peak Re...

BACKGROUND An autogenous arteriovenous fistula is the optimal vascular access for hemodialysis. In the case of brachiocephalic fistula, cephalic arch stenosis commonly develops leading to access failure. We have hypothesized that a contribution to fistula failure is low wall shear stress resulting from post-fistula creation hemodynamic changes that occur in the cephalic arch. METHODS Twenty-t...

Leukocyte adhesion through L-selectin to peripheral node addressin (PNAd, also known as MECA-79 antigen), an L-selectin ligand expressed on high endothelial venules, has been shown to require a minimum level of fluid shear stress to sustain rolling interactions (Finger, E.B., K.D. Puri, R. Alon, M.B. Lawrence, V.H. von Andrian, and T.A. Springer. 1996. Nature (Lond.). 379:266-269). Here, we sho...

The characteristics of physiological blood flow in human carotid arterial bifurcation model have been numerically studied using a fully coupled fluid-structure interaction (FSI) analysis. This computational model with the fluid-structure interaction is constructed to investigate the flow characteristics and wall shear stress in the carotid artery. As the flow begins to decelerate after the peak...

Recently, Mathis et al. (2011) developed a conceptual approach that is able to predict instantaneous wall-shear stress fluctuations in turbulent boundary layers. This approach embeds the scale interaction mechanisms, namely superposition and modulation, into a wall-model capable of predicting the fluctuating component of the streamwise wall-shear stress. The present study investigates the poten...