Personalized brain revascularization: computer modeling of the reconstruction zone for carotid endarterectomy

Abstract

To develop a technique of computer modeling of hemodynamics before conventional CEE. Classical CEE is performed according to conventional patch technique. Duplex parameters of stenosis and blood flow velocity in the carotid arteries were analyzed by using of a linear transducer 7-7.5 MG (Acuson 128XP scanner, Acuson, USA). Multispiral computed tomography with angiography and subsequent processing of data using the Clear canvas software were performed to visualize the main geometric characteristics of the carotid arteries and features of atherosclerotic plaque. Blood flow hemodynamics is essential in the occurrence of postoperative restenosis. Therefore, computer simulation of blood flow using CFD (Computational Fluid Dynamics) methods based on particular patient's data makes it possible to assess localization of zones with high risk of restenosis. CFD approach implies construction of blood flow parameters at absolutely every point of the vessel considering geometric shape of the vessel and flow characteristics at the entrance and exit from the vessel. Pressure curves at the inlet and outlet are constructed using blood flow velocity curves. Pressure curves are subsequently used in the CFD model. The result of blood flow CFD modeling is non-stationary three-dimensional fields of pressure and velocity in the investigated area. Visual analysis of blood flow dynamics in these fields makes it possible to judge possible problem areas along the blood flow and on the inner wall of the vessel. Patch technique of classical CEE is characterized by great risk of parietal thrombosis and hyperproliferation of neointima that explains more frequent development of restenosis. Computer modeling is valuable to consider some important technical aspects in implementation of various surgical techniques for carotid artery reconstruction. This result demonstrates an importance of achieving the optimal ratio of the diameter of common, internal and external carotid arteries. Modification of patch based on computer simulation is required for these purposes.