Authors:   Francesca Condemi, Raffaele Serra, Stefano de Franciscis, Gionata Fragomeni

Abstract

This study regards a computational fluid dynamics (CFD) model and a fluid structure interaction (FSI) model to describe the ?Functional Entrapment Syndrome of Popliteal Artery? (PAES). A stack of 127 slices, were acquired from RM of the right knee. The segmentation of the region of interest was performed on 3D Slicer, using the Single Region Growing. The final geometry was created in Comsol Multiphysics through the measure obtained by segmentation. To optimize the model?s elaboration, we performed only the region of interest the flow, the artery walls and the muscles soleus, medial gastrocnemius, plantaris and popliteus. CFD and FSI were performed using the commercial software Comsol Multiphysics 5.0 (COMSOL, Inc., Stockholm, Sweden). In CFD section, in agreement with the experimental data, the popliteal blood velocity varied from 30[cm/s] to 70 [cm/s]. In FSI phase, the entrapment due to the gastrocnemius muscle caused a maximum displacement of the popliteal artery walls of 0.16 [mm]. When the entrapment is due to soleus muscle, the maximum displacement of the artery is about 0.3947 [mm]. The most important observation is the variation of contact pressure in two cases of entrapment. In fact, when the occlusion is due to soleus muscle, the pressure is higher than the precedent case. The CFD model and the FSI model resulted in a detailed description of fluid dynamic and fluid-structure interactions useful to evaluate the pathology?s features, independently, from the obstacles of in vivo analysis. These models can define the sites more solicited where there is the most probability to have an aneurysm.