Which characteristic is NOT consistent with total occlusion of the ICA?

Purely retrograde flow in the distal internal carotid artery (ICA) is not a characteristic consistent with total occlusion of the ICA. When the ICA is totally occluded, it means that there is a complete blockage preventing any flow from passing through the vessel. In such cases, the flow dynamics would not exhibit retrograde flow in the distal ICA. Instead, if the ICA is occluded, blood flow may be redirected to collateral pathways, but no flow would be present in the distal segment of the occluded artery itself.

In total occlusion scenarios, the absence of flow in the ICA lumen is expected, along with decreased velocity proximal to the occlusion due to reduced or altered hemodynamics leading to sluggish flow. Collateral circulation may increase, leading to more flow through alternative vessels rather than any flow in the distal ICA itself. Therefore, the presence of purely retrograde flow in such a situation contradicts the established hemodynamic principles associated with total occlusion.