基于3D打印技术构建颈动脉粥样硬化预测模型的研究

The carotid artery bifurcation is a common sit of atherosclerosis which is a leading etiology for ischemic stroke. The unique hemodynamic feature related to the geometry of carotid bifurcation is a major cause for the atherosclerosis predilection in this location. Investigating the hemodynamic factors associated with carotid atherosclerosis, therefore, garnered much research interests in recent years. Most previous studies of this kind utilized computer hemodynamic models for analyzing the hemodynamic factors associated with carotid atherosclerosis. One obvious shortage of computer hemodynamic models lies in that they cannot analyze the effects of eddied or turbulent flows, because most of computer hemodynamic models are based on laminar flow theory, so the effects of eddied or turbulent flows are omitted. But eddied or turbulent flows are very common in carotid bifurcations and they are an important hemodynamic factor influencing atherosclerosis. ..Base on this consideration, this study will obtain geometry parameters of carotid bifurcation with computer tomography angiography (CTA), and obtain structural parameters of carotid with ultrasound scan. Both parameters will be used for 3D printing to construct a lifelike carotid phantom. This carotid phantom will be used in vitro for evaluating the hemodynamic profiles in carotid bifurcation. A new blood-mimicking fluid will be developed for particle image velocimetry (PIV), which can measure the local velocity field, and then identify the factors associated with shear stress changes in the lumen. With these data, hemodynamic factors influencing carotid atherosclerosis can be identified. By including classic risk factor, such as age, blood pressure, blood glucose level, smoking status, blood lipid level, a predictive model for carotid atherosclerosis can be constructed. One advantage of this predictive model is that it will include both hemodynamic factors and classic risk factor for atherosclerosis, which is presumed to increase the accuracy of prediction. This predictive model will be then justified in a patient cohort selected form Nanjing Stroke Registry Program (NSRP). NSRP is inaugurated in 2003 with more than 6500 first-ever stroke patients registered. Most registered patients have baseline and follow-up carotid vascular imaging examinations. These on-hand data will be used to evaluate the factors associated with development and deterioration of atherosclerosis, and provide subjects for evaluating the accuracy (sensitivity and specificity) of the model in predicting initiation, progress and plaque rapture of carotid atherosclerosis. ..The model is expected to help in making personalized strategies for preventing and treating carotid atherosclerosis. To our knowledge, there have been no reported studies to date in which a 3D printing carotid phantom is used for constructing a carotid atherosclerosis predictive model.

颈动脉粥样硬化是缺血性脑血管病的重要病因。以往研究颈动脉粥样硬化的生物力学机制时，多采用计算机流体力学模型。然而，颈动脉分叉部独特的几何形态使该处腔内血流易发生涡流和湍流，计算机模型难以模拟这些复杂的流场特征，而涡流和湍流又恰恰是诱发局部动脉粥样硬化的关键流体力学因素。为解决这一问题，本研究拟采用CTA和 OCT获取颈动脉几何形态参数，采用超声扫描获取颈动脉结构参数，利用3D打印制备高仿真颈动脉模型。借助粒子成像测速技术和模拟血液流体技术，在体外直接观测颈动脉几何形态和管壁结构特征对流场的影响，进而确定影响颈动脉粥样硬化发生和发展的流体力学因素。在纳入主要传统危险因素后，建立颈动脉粥样硬化发生、发展和斑块破裂的综合预测模型。以我们多年前建立的南京卒中注册系统为平台，提取既往患者颈动脉影像检查结果，对该模型的准确性进行评估。该预测模型有望为临床制定个体化的颈动脉粥样硬化防治方案提供参考。

颈动脉粥样硬化是缺血性脑血管病的重要病因。以往研究颈动脉粥样硬化的生物力学机制时，多采用计算机流体力学模型。然而，颈动脉分叉部独特的几何形态使该处腔内血流易发生涡流和湍流，计算机模型难以模拟这些复杂的流场特征，而涡流和湍流又恰恰是诱发局部动脉粥样硬化的关键流体力学因素。为解决这一问题，本研究采用了CTA、血管超声和OCT获取颈动脉几何形态参数，采用超声扫描获取颈动脉结构参数，利用3D打印制备高仿真颈动脉模型。借助粒子成像测速技术和模拟血液流体技术，在体外直接观测颈动脉几何形态和管壁结构特征对流场的影响，进而确定影响颈动脉粥样硬化发生和发展的流体力学因素。在纳入主要传统危险因素后，建立颈动脉粥样硬化发生、发展和斑块破裂的综合预测模型。以我们多年前建立的南京卒中注册系统为平台，提取既往患者颈动脉影像检查结果，对该模型的准确性进行评估。该预测模型可以为临床制定个体化的颈动脉粥样硬化防治方案提供参考。