一种新型可回收腔静脉滤器血流动力学分析

腔静脉滤器是为防止下肢及盆腔的血栓脱落上行导致肺栓塞而设计的一种过滤性装置。本研究设计了一款新型腔静脉滤器,为评价其在植入后的血流动力学性能和血栓捕捉效果,利用计算流体力学的方法与已上市的两种滤器德纳里(Denali)和护盾(Aegisy)进行血流动力学数值模拟比较,并实施体外实验测试对比血栓捕捉效果。本文的研究主要运用计算流体力学软件,分析血栓直径分别为5、10、15 mm,血栓浓度含量分别为10%、20%、30%的情况下,流域段的出口流速、出入口压差、滤器壁面上的壁面剪应力、高低壁面剪应力区域面积占比以及滤器的血栓捕捉效果,同时还通过体外实验数据对比评价了以上3种滤器的血栓捕捉效果。研究结果显示,Denali滤器植入后对血流的干扰最小,但对5 mm小直径血栓的捕捉效果最差;Aegisy滤器对不同直径和浓度含量的血栓捕捉效果最优,但低壁面剪应力区域面积占比最大;本研究设计的新型滤器对小直径血栓有较好的捕捉效果,且该滤器上易导致血栓形成的低壁面剪应力区域面积占比最小;Denali和Aegisy滤器的低壁面剪应力区域面积占比相对较大,形成血栓的风险较高。基于以上结果,期望本文设计的新型腔静脉滤器能为新型滤器的设计和临床选择提供参考依据。

Hemodynamic analysis of a new retrievable vena cava filter

Vena cava filter is a filter device designed to prevent pulmonary embolism caused by thrombus detached from lower limbs and pelvis.A new retrievable vena cava filter was designed in this study.To evaluate hemodynamic performance and thrombus capture efficiency after transplanting vena cava filter,numerical simulation of computational fluid dynamics was used to simulate hemodynamics and compare it with the commercialized Denali and Aegisy filters,and in vitro experimental test was performed to compare the thrombus capture effect.In this paper,the two-phase flow model of computational fluid dynamics software was used to analyze the outlet blood flow velocity,inlet-outlet pressure difference,wall shear stress on the wall of the filter,the area ratio of the high and low wall shear stress area and thrombus capture efficiency when the thrombus diameter was 5 mm,10 mm,15 mm and thrombus content was 10%,20%,30%,respectively.Meanwhile,the thrombus capture effects of the above three filters were also compared and evaluated by in vitro experimental data.The results showed that the Denali filter has minimal interference to blood flow after implantation,but has the worst capture effect on 5 mm small diameter thrombus;the Aegisy filter has the best effect on the trapping of thrombus with different diameters and concentrations,but the low wall shear stress area ratio is the largest;the new filter designed in this study has a good filtering and capture efficiency on small-diameter thrombus,and the area ratio of low wall shear stress which is prone to thrombosis is small.The low wall shear stress area of the Denali and Aegisy filters is relatively large,and the risk of thrombosis is high.Based on the above results,it is expected that the new vena cava filter designed in this paper can provide a reference for the design and clinical selection of new filters.