TEVAR术后假腔重塑血液两相流动调控的大涡模拟研究

Thoracic aortic dissection is a cardiovascular disease, which is a serious hazard to human health. Endovascular repair (TEVAR) reduces mortality of aortic dissection and has become the preferred way to treat the disease. Studies have shown that a variety of complications after TEVAR are related to false lumen remodeling (FLR) of the dissection, but the path-physiological changes of FLR is still lack of sufficient understanding. To deeply investigate this issue, this project proposes to develop direct numerical simulation ( DNS) and large eddy simulation ( LES) for two-phase blood flows. The two-fluid model and immersed boundary method will be incorporated to deal with the interactions between fluid and complex boundaries. First, abundant cases of aortic dissection patients will be enrolled and 3D CT measurement technology combined with mechanical testing will be used to establish geometric model calculations, the initial and boundary conditions, and the vascular wall constitutive model. The developed LES-IBM method will be then applied to study the two-phase blood flow characteristics in the thoracic aortic dissection. The results will be analyzed to quantify the relationship between hemodynamic parameters and thrombosis of the false lumen remodeling so that we can verify the accuracy of the numerical simulation by clinical follow-up results, control blood pressure after guiding post-operative drug-use, reduce re-intervention rate of TEVAR post-operatively, and finally, improve the quality of long-term survival of patients.

胸主动脉夹层（AD）是一种严重危害人类健康的心血管疾病。腔内修复术（TEVAR）降低了AD的死亡率，已成为治疗该种疾病的首选方式。以往研究表明TEVAR术后多种并发症的发生与夹层假腔重塑（FLR）有关，但对于FLR病理生理变化仍缺乏足够认识。为了深入研究这一问题，本项目提出发展血液两相流动的直接数值模拟（DNS）和大涡模拟方法(LES)，将双流体模型和内嵌边界方法（IBM）相结合，同时处理复杂边界血液两相流动及流固耦合作用。首先基于大量AD病例，采用三维CT测量技术结合力学性能测试，获取AD的几何模型、初始边界条件和血管壁本构模型；其次采用发展的双流体LES-IBM方法对AD血液两相流动特性进行研究，依据所得结果分析红细胞、血流动力学参数与血栓形成、夹层假腔重塑间关系，通过临床随访结果验证数值模拟的准确性，指导术后合理用药，控制血压，降低TEVAR术后的再次干预率，提高患者长期生存质量。

胸主动脉夹层是一种严重危害人类健康的心血管疾病。腔内修复术（TEVAR） 降低了主动脉夹层的死亡率，已成为治疗该种疾病的首选方式。以往研究表明 TEVAR 术后多种并发症的发生与夹层假腔重塑（FLR）有关，但对于 FLR 病理生 理变化仍缺乏足够认识。为了深入研究这一问题，考虑血液两相流动及流固耦合作用的数值模拟可很好研究主动脉夹层手术前后主动脉腔内的血流动力学。本研究1.获取了不同人群主动脉详细的几何、边界及生物力学参数；2.建立真实的胸主动脉夹层模型以及液固两相流双流体模型；3.探索了LSA覆盖对TEVAR手术前后血管腔内血流动力学的影响；4.探索结合原位开窗技术的TEVAR手术（ISF-TEVAR）前后主动脉腔内的血流动力学；5.探索两开窗ISF-TEVAR术后主动脉腔内的血流动力学；6.探索影响ISF-TEVAR术后主动脉腔内血流动力学的因素，发展了虚拟ISF-TEVAR手术。对主动脉夹层及累及主动脉弓部病变的手术治疗进行了探索。