HEMODYNAMICS OF A SIMULATION OF THE VERTEBROBASILAR SYSTEM USING SILICONE TUBE

We investigated the hemodynamics of the vetebrobasilar system (VBS) us ing a simulation model tube made of silicone which had different diame ters between the bilateral vertebral artery (VA) ducts (stenotic and n ormal VA ducts). Using the ultrasonic Doppler method, the laterality i ndex (L.I.) of the flow velocity in the VA duct was 32.88%. The flow v olume of the anterior inferior cerebellar artery duct and the posterio r inferior cerebellar artery duct also had significant laterality. By investigating the effects of the rotatory pulse rate and fluid viscosi ty, a maximal decrease to below 40-50% of the flow volume of the branc hes, and to below 71.93% in the mean how velocity of the basilar arter y (BA) duct (BA duct) were observed, and the maximum L.I. increased to 43.15%. When the unilateral stenotic VA duct was occluded by clamping (clamping occlusion), the how volume profiles of the branches were th e same as without clamping occlusion. The L.I. showed no significant c hanges and the maximal decrease in the mean flow velocity of the BA du ct was 68.61%. Using the laser Doppler method, the flow velocity distr ibution of the BA duct was shifted towards the side of the stenotic VA duct. These results suggest that the theological dynamics in the main vessels can certainly reflect the posterior circulatory dynamics, and that modulating factors also aggravate the hemodynamics of the VBS wi th this disorder.