Comparative study of hemodynamic parameters in carotid bifurcation in presence of different shaped clots in thromboembolism

Arterial embolism is one of the major causes of brain infarction. Investigating hemodynamic factors of this phenomenon can help us to get a better understanding of it and can be useful to devise ways for preventing ischemic strokes. Carotid artery is one of the primary tracts that emboli can go toward the brain through it. In the previous works, researchers modeled clots just in spherical shape which seems to be idealized. So, we decided to evaluate the effect of clot geometry on hemodynamic factors. We used a 3D model of carotid bifurcation based on what reported about its sizes in previous computational models. We used a hyperelastic model for the clots’ mechanical property and modeled them in spherical and elliptical geometries. The governing equations of the fluid are Navier-Stokes and continuity equations and have been solved in an arbitrary Lagrangian -Eulerian (ALE) formulation through fluid-structure interaction method. The speed of both clots is measured and shear stress on the inner wall of the carotid artery and in clots is calculated in the both models. Results revealed that maximum magnitudes of shear stress are 70.0218 Pa in elliptical clot and 70.3812 Pa in spherical clot. According to what we achieved, the geometry of emboli has significant role in hemodynamic factors. So, trying to use a realistic morphology of emboli based on what observed and reported by neurosurgeons can help us to reach a better understanding of this phenomenon.

Keywords:

Arterial embolism , Ischemic stroke , Fluid-Structure Interaction (FSI) , Hyperelastic model.