STA-MCA anastomosis is known as one of the surgeries for the stroke prevention, which intended to perfuse the cerebral artery. However, this surgical remedy has no general criterion. To assess the effect of this operation, Computational Fluid Dynamics (CFD) is performed for two patients. The vascular lumen geometries are extracted from patient's 3D-DSA images. Additionally, different anastomosis conditions, bypass angle or site, are assumed. As a results, there is a little change in mass flow rate between conditions of the different bypass angle. In contrast, mass flow rate of the M2-part bypass increases at more branch arteries than that of the M4-part bypass. This may mean M2 bypass form could be more effective than M4 bypass one.
