Patient based computational fluid dynamic characterization of carotid bifurcation stenosis before and after endovascular revascularization
- 1Division of Neurosurgery, Baystate Medical Center, Springfield, Massachusetts, USA
- 2Department of Neurosurgery, Tufts Medical Center, Boston, Massachusetts, USA
- Correspondence to Dr A M Malek, Department of Neurosurgery, Tufts Medical Center, 800 Washington St, No 178, Boston, MA 02111, USA;
Contributors CMS and AMM contributed equally to the manuscript.
- Received 3 May 2011
- Accepted 3 September 2011
- Published Online First 28 October 2011
Introduction Hemodynamic forces play a critical role in determining the molecular phenotype of the endothelial cell and in influencing vascular remodeling. A lesion based computational fluid dynamic (CFD) modeling approach is presented to understand the complex spatial and temporal hemodynamic changes that prevail in carotid stenosis (CS) in patients with critical CS undergoing carotid artery stenting (CAS).
Methods High resolution three-dimensional rotational angiography volumetric datasets were acquired before and after treatment in eight patients, segmented and used to generate a high quality structured hexahedral computational mesh with boundary layer refinement. CFD analysis was carried out using a time dependent laminar flow model implementing non-Newtonian realistic blood viscosity for blood, and used to compute wall shear stress (WSS) and its gradient (WSSG).
Results CAS restored fully or near laminar flow in all cases in our series. In addition, WSS was found to decrease in the stented region in all cases, reduced to near normal levels of 34±14 dyn/cm2 with significant blunting of the extreme pretreatment WSSG to levels lower than 1000 dyn/cm3.
Conclusions In this series of patients with symptomatic CS, CFD simulation enabled estimation of the hemodynamic effect of CAS, leading to reversal of abnormal flow patterns and wall shear forces around the arterial stenosis, with normalization of flow laminarity and wall shear spatiotempotal patterns known to be associated with adverse endothelial cell function.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.