The Effect of an Implanted Filter on Valsalva-Compression and Respiratory-Compression of the Inferior Vena Cava

We carry out computational simulations of the Valsalva compression of an inferior vena cava (IVC) with a filter implanted in it. We find that when we treat the IVC wall as simply a boundary between 2 fluids and apply an external pressure on the IVC, the deformation magnitudes and patterns do not agree with data in the literature. We conclude that IVC compression is mainly caused by solid bodies (i.e. tissue and organs) compressing the IVC, and develop a model to simulate this phenomenon. We calibrate our model to data in the literature for Valsalva compression with and without an implanted filter. We then use our approach to predict the area reduction of the IVC during breathing when 2 different types of filters are implanted. Not surprisingly, we find that a compliant filter is less able to resist the compression of the IVC during respiration than a stiffer one, and we quantify the difference. We anticipate that, with further development, our model can be used to make assessments of design and testing parameters that can help to avoid fatigue failure of a filter that is subjected to millions of compressions due to breathing.