Alteration On Blood Flow in The Middle Cerebral Artery Influenced by sickle Cell Anemia: Computational Fluid Dynamics Analysis
Sickle cell anemia (SCA) is a common hereditary blood disorders which increase stroke risk in children.Transcranial Doppler sonography(TCD) is an effective tool to identify patient-at-risk and suggesting advanced treatment, patient with time-averaged mean maximum velocity (TAMMV) greater than 200 cm/s have higher risk of stroke. The aim of this study is usethe computational fluid dynamics method to investigatehemodynamicsalterations by blood viscosity, velocity and vessel stenosis.Geometric modelswere created by SolidWorks, and one was given a stenosis at proximalmiddle cerebral artery (MCA). Blood was assumed incompressible Newtonian fluid. The pulsatile inlet TAMMV of the ICA was at 40cm/s for non-SCA and 70cm/s for simulating SCA. The outlet conditions of ACA, M2-A and M2-B were constant pressure of 0 mmHg. ANSYS was used to solve the blood flow. Blood viscosities were 3 and10 cP for the healthy and SCA cases, respectively, in simulation.None of the situation in non-stenosis group exceeded 200 cm/s even with the TAMMV of inlet given as 70 cm/s and blood viscosity given as 10 cP. The regions of flow recirculation were consistent with the low WSS zones indicated higher risk of intimal hyperplasia, atherosclerosis, stenosis formation. As comparing the stenosis group with the non-stenosis ones higher velocity and larger area of low WSS were found. We observed that computational fluid dynamics analysis could provide an insight of the interplay between blood property and vascular geometries caused by SCA.
Keywords- Sickle Cell Anemia, Middle Cerebral Artery, Stroke, Computational Fluid Dynamics Analysis