Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science & Medical Engineering, Beihang University, Beijing 100191, China.
Med Hypotheses. 2011 Dec;77(6):990-2. doi: 10.1016/j.mehy.2011.08.028. Epub 2011 Sep 7.
The blockage of a vena cava filter (VCF) by the captured blood clots presents a serious problem to the patients. Commercially available cone-shaped VCFs such as the Gunther Tulip filter has an inherent structural flaw that leads the captured blood clots to be trapped in their front spire areas where the flow-induced shear stress is relatively low so that the clots cannot dissolve fast enough and will accumulate, gradually block the central passages of the filters. It is well known that for a Hagen-Poiseuille flow in a circular tube, the flow-induced shear stress is highest at the wall of the tube and lowest along its axis. Herein, we hypothesize that by reversely deploying a cone-shaped filter in the vena cava, the filter's blockage problem might be prevented. First of all, this kind of deployment scenario can force the captured blood clots to stay in the peripheral areas of the vena cava and keep the central passage of the filter unblocked. Secondly, this scenario can expose the captured blood clots to relatively high shear stress that may dissolve the clots faster.
腔静脉滤器（VCF）被捕获的血栓阻塞会给患者带来严重的问题。市售的圆锥形 VCF ，如 Gunther Tulip 滤器，存在一个固有的结构缺陷，导致捕获的血栓被困在其前尖区域，血流诱导的剪切力相对较低，因此血栓不能快速溶解，并会逐渐积聚，逐渐阻塞滤器的中央通道。众所周知，对于圆管中的哈根-泊肃叶流动，流动诱导的剪切力在管壁处最高，沿其轴处最低。在此，我们假设通过将圆锥形滤器反向部署在腔静脉中，可以防止滤器的阻塞问题。首先，这种部署方案可以迫使捕获的血栓留在腔静脉的外围区域，并保持滤器的中央通道畅通。其次，这种情况可以使捕获的血栓暴露在相对较高的剪切力下，这可能会更快地溶解血栓。
