Subclavian Steal Syndrome – A Computer Model Approach

Subclavian steal syndrome is a constellation of signs and symptoms that arise from retrograde (reversed) flow of blood in the vertebral artery or the internal thoracic artery, due to a proximal stenosis (narrowing) and/or occlusion of the subclavian artery. The present study aim to describe this syndrome in patients with subclavian steal steno-occlusive disease based on a computer lumped parameter model. It is studied the cerebral circulation starting from the aortic arch till the arterial branches leaving the circle of Willis. The governing equations of the model are based on the conservation of mass on each node of arteries and on conservation of energy in every loop consisted of artery branches. In addition, the energy loss equation is employed for every artery branch. The system of the equations describing the model is solved with MATLAB. The results show that when the short low resistance path (along the subclavian artery) becomes a high resistance path (due to narrowing) blood flows around the narrowing via the arteries that supply the brain (left and right vertebral artery, left and right internal carotid artery).