心血管手术规划的血流动力学数值研究

发布时间：2018-04-11 00:17

本文选题：血流动力学 + 心血管疾病　；参考：《北京工业大学》2013年博士论文

【摘要】：血流动力学因素直接作用于血管内皮细胞，对内皮细胞的生理和病理功能具有调节作用。研究发现，在血管分叉、弯曲、动脉瓣膜等部位存在异常和不均匀的血流动力学因素，包括流动分离、涡流、高压、低壁面切应力、振荡剪切应力、长粒子滞留时间、二次流等。这些异常的血流动力学因素能够引起血管内膜增生、内皮细胞损伤等，导致血管壁面处动脉粥样硬化斑块的形成，被普遍认为是血管病变产生与发展的重要原因，称为粥样硬化危险性血流动力学因素。危险性血流动力学因素除发生在上述特定血管部位之外，在心血管搭桥手术局部位置也存在，可能会导致手术部位的血管内膜增生，造成术后血管再狭窄、移植血管病变等临床症状，影响着手术的成败及长期有效性。因此，在心血管疾病的手术过程中，也必须充分考虑血流动力学因素。心血管疾病治疗的手术规划就是在术前通过对各种手术方案可能产生的血流动力学因素进行预测和比较，避免危险性血流动力学因素，，从而优化术后的血流动力学，为手术决策提供依据。本论文以优化手术血流动力学，辅助心血管手术决策为目的，开展了单心室、Fallot四联症和冠状动脉狭窄三种心血管疾病的血流动力学研究，从搭桥手术几何多样性角度研究了不同手术方式的血流动力学特征，评估了不同搭桥几何对手术效果的影响，为临床手术决策和疾病预防提供了理论依据。论文的研究内容包括以下几方面：（1）个性化心血管手术建模研究：主要包括两部分工作，一是基于医学图像的个性化解剖模型三维重建；二是基于重建模型，利用虚拟现实技术开发心血管手术虚拟建模工具，实现心血管手术虚拟操作，构建了血流动力学仿真所需的个性化手术模型。（2）单心室手术模型的血流动力学数值研究：研究了治疗单心室疾病的Fontan手术的三个步骤，主要研究了不同搭桥位置、角度、血管直径等几何因素对血流动力学的影响，寻找最优化的搭桥几何结构，达到分离体循环和肺循环、减小手术后的能量损失、实现肝静脉血向两肺的平均分流、实现腔静脉血向左右肺动脉的平均灌注、减少涡流及低壁面切应力等危险性血流动力学现象的目的，提高手术的长期有效性。（3）法洛氏四联症手术模型的血流动力学数值研究：研究了两种常用的体肺分流术，即改良的BT手术和中央分流术。着重分析了搭桥管的局部血流动力学内环境，定量分析了主动脉向肺动脉的血液灌注比，搭桥后左、右肺动脉的分流比等，指导临床医生更好的认识体肺分流术，辅助临床体肺分流术的决策。（4）冠状动脉狭窄手术模型的血流动力学数值研究：研究了冠状动脉不同狭窄率时竞争流对搭桥管内血流动力学的影响，探索竞争流与搭桥管失败之间的关系；研究了传统冠状动脉搭桥术后血管内的血流动力学，发明了一种双移植管搭桥方式来增加手术后的血管通透性，减小冠状动脉再狭窄的发生几率。论文通过血流动力学因素的优化来优化搭桥血管几何结构，建立了一套医学图像三维重建-虚拟心血管手术建模-血流动力学计算与评估相结合的心血管疾病手术规划理论和方法，对促进血流动力学的临床应用、提高心血管手术的科学化水平具有理论意义和潜在的应用价值。
[Abstract]:The direct effects of hemodynamic factors on vascular endothelial cells, play a role in the regulation of physiological and pathological function of endothelial cells. The study found that bending in the vascular bifurcation, abnormal hemodynamic factors and uneven aortic valve and other parts, including flow separation, vortex flow, high pressure, low wall shear stress, shear oscillation long force, particle residence time, the two time flow. These abnormal hemodynamic factors can cause vascular intimal hyperplasia, endothelial cell damage, resulting in the formation of vascular wall of atherosclerotic plaque, is generally considered to be an important cause of the emergence and development of vascular lesions, called atherosclerosis risk of hemodynamic factors.
In addition to the occurrence of the risk factors of hemodynamics in addition to the above specific vascular site also exists in the local position of cardiovascular bypass surgery may lead to intimal hyperplasia in the surgical site, causing restenosis after angioplasty, the clinical symptoms of transplant vasculopathy, affect the success of the surgery and long-term effectiveness. Therefore, in the operation process of cardiovascular disease in, we must fully consider the hemodynamic factors. Surgical planning for the treatment of cardiovascular disease is by preoperative hemodynamic factors on various surgical options may produce prediction and comparison of hemodynamics to avoid risk factors, so as to optimize the hemodynamics after operation, and provide the basis for the surgical decision.
In this paper, in order to optimize the operation of hemodynamics, cardiovascular surgery assisted decision to carry out single ventricle, hemodynamics of tetralogy of Fallot and coronary artery stenosis in three kinds of cardiovascular diseases, from the perspective of bypass geometric blood flow mechanics characteristics of different surgical methods, evaluated the effects of different bypass geometry on the result of the operation that provides a theoretical basis for clinical decision-making and disease prevention.
The research contents of this paper include the following aspects:
(1) modeling of personalized cardiovascular surgery: mainly includes two parts, one is the medical image three-dimensional reconstruction model based on personalized anatomy; two is based on the reconstruction model, using virtual reality technology to develop virtual modeling tools to achieve cardiovascular surgery, cardiovascular surgery virtual operation, then the individual operation model of hemodynamic simulation is required.
(2) study on the hemodynamic numerical model of single ventricle surgery: three steps to study the surgical treatment of single ventricle disease Fontan, angle was studied, the effect of vascular bypass position, diameter of geometrical factors on hemodynamics, to find optimal bypass geometry to separate, systemic and pulmonary circulation, reduce the energy loss after surgery, hepatic venous blood to achieve average pulmonary shunt in two, cavity venous blood to the average perfusion of pulmonary arteries, reduce the eddy current and the low wall shear stress and other dangerous hemodynamic phenomena to improve the long-term effectiveness of surgery.
(3) study on the hemodynamic values of tetralogy of Fallot surgery model: a study of two common pulmonary shunt, the modified BT operation and the central shunt. Focuses on the analysis of the local hemodynamics in the bypass pipe environment, quantitative analysis of the aorta to the blood perfusion of pulmonary artery bypass ratio, left, right the ratio of pulmonary artery shunt, guide clinicians better understand pulmonary shunt assisted clinical systemic pulmonary shunt decision.
(4) on the hemodynamics of coronary artery stenosis surgery numerical model of coronary artery stenosis rate when the competition flow effect on the hemodynamics in the bypass pipe and bypass pipe flow, explore the competitive relationship between failure; hemodynamic blood vessels in conventional coronary artery bypass grafting after research, invented a double bypass graft to increase vascular permeability after surgery, reduce the incidence of coronary artery restenosis.
Through the optimization of hemodynamic factors to optimize the bypass vessel geometry, established the calculation and evaluation of a medical image 3D reconstruction of virtual modeling of hemodynamics in cardiovascular surgery combined with cardiovascular surgery planning theory and method of clinical application of promoting blood flow dynamics, has theoretical significance and potential application value to improve the scientific the level of cardiovascular surgery.

【学位授予单位】：北京工业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R318.01

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