Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA.
Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, USA.
Sci Rep. 2024 May 2;14(1):10092. doi: 10.1038/s41598-024-60666-7.
Carotid artery webs (CaW) are non-atherosclerotic projections into the vascular lumen and have been linked to up to one-third of cryptogenic strokes in younger patients. Determining how CaW affects local hemodynamics is essential for understanding clot formation and stroke risk. Computational fluid dynamics simulations were used to investigate patient-specific hemodynamics in carotid artery bifurcations with CaW, bifurcations with atherosclerotic lesions having a similar degree of lumen narrowing, and with healthy carotid bifurcations. Simulations were conducted using segmented computed tomography angiography geometries with inlet boundary conditions extracted from 2D phase contrast MRI scans. The study included carotid bifurcations with CaW (n = 13), mild atherosclerosis (n = 7), and healthy bifurcation geometries (n = 6). Hemodynamic parameters associated with vascular dysfunction and clot formation, including shear rate, oscillatory shear index (OSI), low velocity, and flow stasis were calculated and compared between the subject groups. Patients with CaW had significantly larger regions containing low shear rate, high OSI, low velocity, and flow stasis in comparison to subjects with mild atherosclerosis or normal bifurcations. These abnormal hemodynamic metrics in patients with CaW are associated with clot formation and vascular dysfunction and suggest that hemodynamic assessment may be a tool to assess stroke risk in these patients.
颈动脉血管壁（CaW）是向血管腔突出的非动脉粥样硬化性突起，与年轻患者中多达三分之一的隐源性中风有关。确定 CaW 如何影响局部血液动力学对于理解血栓形成和中风风险至关重要。使用计算流体动力学模拟研究了具有 CaW 的颈动脉分叉处、具有相似管腔狭窄程度的动脉粥样硬化病变的分叉处和健康的颈动脉分叉处的患者特异性血液动力学。使用从二维相位对比 MRI 扫描提取的入口边界条件对分段计算机断层血管造影几何形状进行了模拟。该研究包括 13 例具有 CaW 的颈动脉分叉处、7 例轻度动脉粥样硬化和 6 例健康分叉处。计算并比较了与血管功能障碍和血栓形成相关的血流动力学参数，包括剪切率、振荡剪切指数（OSI）、低速度和血流停滞，并在受试者组之间进行比较。与轻度动脉粥样硬化或正常分叉的患者相比，CaW 患者的低剪切率、高 OSI、低速度和血流停滞的区域明显更大。这些 CaW 患者的异常血流动力学指标与血栓形成和血管功能障碍有关，这表明血流动力学评估可能是评估这些患者中风风险的一种工具。
