COMPUTER MODELING OF CEREBRAL BLOOD-FLOW FOLLOWING INTERNAL CAROTID-ARTERY OCCLUSION

It is difficult to predict the adequacy of the collateral blood flow i n patients who undergo internal carotid artery occlusion. In order to address this difficulty, the authors have created a computer model of the cerebral circulation. This model features individualized simulatio ns of the Circle of Willis and its afferent and efferent branches whic h can predict changes in flow that will occur during internal carotid artery occlusion. Analysis of the flow predictions suggests that in pa tients with a symmetric Circle of Willis the anterior communicating ar tery is the major conduit of collateral blood supply. In patients with a small anterior communicating artery, the posterior communicating ar teries become more important as sources of collateral flow but they ca nnot supply as much flow as in the case of a normal anterior communica ting artery. Sensitivity studies show that changes in the dimensions o f each artery affect the now throughout the system, such that the arte ries in the cerebral circulation must be analyzed as a network rather than as isolated elements. This computer model of the cerebral circula tion may help clinicians predict the adequacy of collateral blood supp ly in patients who undergo internal carotid artery occlusion.