3种可转换型腔静脉滤器过滤血栓效果的对比分析

目的 研究不同血栓直径和血栓含量下可转换型腔静脉滤器用于肺动脉栓塞治疗后的过滤血栓效果。方法 构建3种过滤单元形状（L型、S型和W型）的可转换型腔静脉滤器模型，利用计算流体力学方法进行血流动力学数值模拟，对比分析不同直径（5、10、15 mm）和不同含量（10%、15%、20%）血栓条件下的过滤血栓效果。结果 血栓直径越大，含量越多，滤器滤杆上分布的血栓体积分数越大，滤器的过滤血栓效果越好。当血栓直径为5 mm时，与其他两种滤器相比，S型滤器的过滤效果最好；当血栓直径为10 mm时，W型滤器的过滤效果最好；而在血栓直径为15 mm时，S型滤器与W型滤器的过滤效果相同，均比L型滤器的过滤效果好。结论 滤器的植入造成了血流动力学的改变，它的过滤效果不仅与过滤单元结构有关，还与血栓含量和血栓直径大小有着密切相关。研究结果为新型可转换型腔静脉滤器的设计和临床选择提供了理论参考依据。
Objective To investigate filtration efficiency of convertible vena cava filters on treating pulmonary embolism under the condition of different thrombus diameter and content. Methods Three kinds of convertible vena cava filter models with different filtering unit structures (L-style, S-style, W-style) were constructed to numerically simulate hemodynamics based on computational fluid dynamic (CFD) methods, and their filtration efficiency were comparatively analyzed under the condition of different thrombus diameter (5, 10, 15 mm) and content (10%, 15%, 20%). Results With the increasing of thrombus diameter and content, the volume fraction of thrombus distributed on the filter bars increased and filtration efficiency of the filter became better. When the thrombus diameter was 5 mm, the S-style filter’s filtration efficiency was the best as compared with the other two styles of filters. When the thrombus diameter was 10 mm, the W-style filter showed the best filtration efficiency. When the thrombus diameter was 15 mm, the S-style and W-style filter showed the same filtration efficiency, which was better than the L-style filter. Conclusions The implantation of vena cava filters will cause hemodynamic changes, and its filtration efficiency is not only related to filtering unit structures, but also closely related to the diameter and content of thrombus. These results provide a theoretical reference basis for the design and clinical choice of the novel convertible vena cava filter.