Patient Specific study on Haemodynamic changes in Pre and Post Stenting of Carotid Bifurcation System using Numerical Methods

Abstract

The carotid artery is one of the major arteries in the circulatory system which supplies blood to brain, face and neck region of the body. Among the population geometry of carotid artery will be varying based on the ethnicity, height and gender. The Common Carotid Artery (CCA) will be branching into Internal Carotid Artery (ICA) supplies blood to brain and External Carotid Artery (ECA) supplies blood to neck and face. Near the bifurcation towards ICA there will be a expanded region called carotid bulb or sinus, this is the region where most likely stenosis occurs. The Carotid Artery Stenting (CAS) is a minimally invasive alternative for carotid endarterectomy, but the downside is post-stenting complications like late thrombosis and restenosis. The impact of Carotid Artery Stenting (CAS) can be determined using quantitative assessment, which involves understanding the long-term outcomes of CAS, which are clinically debatable. Haemodynamic parameters related to the flow of blood in stented vessels influence post-stenting complications, so studying the blood flow in post-stenting geometry of the Carotid artery is essential. This study compares the blood flow in Pre and Post stenting geometry of 3 patient specific stenosed carotid arteries, for Post stenting geometry two types of stent designs (Open cell and Closed cell) are considered. The following geometries are analyzed using a pulsatile velocity inlet and pressure outlet boundary conditions. From the comparison of haemodynamic factors, the performance of different stent designs used for different geometry shapes of the stenosed carotid artery can be determined. The lower value of Wall Shear Stress (WSS) was observed near the carotid bulb region, which indicates the chances of restenosis. A higher value of the Oscillatory Shear Index (OSI) was also observed in the posterior part of the Internal and External carotid artery. The outcome of the blood flow analysis implies that, closed-cell stent design can be preferred for stenosed carotid artery having a straight shape, and an open-cell stent design can be used for the tortuous-shaped carotid artery.