Even blood vessels sometimes need blood vessels! The vasa vasorum are small blood vessels that supply blood flow to the walls of larger blood vessels. These vessels are not typically observed on cerebral angiography, but in the case of carotid occlusion, they may serve as collateral bridging vessels to restore antegrade flow through the vessel.

Here is an example of a particular challenging case to diagnose:

An older patient came in with a remote history of right sided watershed stroke. He had been neurological stable for the past 1 year. He was transferred from another hospital due to concern for an “intraluminal unstable thrombus” in the right internal carotid artery.

Here is the initial angiogram:

On this initial 2D angiogram, it is difficult to determine what is going on. Is there an intraluminal thrombus? Why does the course of the cervical ICA look so disjointed? What is the degree of stenosis? In this case, a 3D rotational angiogram is important to further clarify the pathology.

Here is the 3D angiogram:

And here is the axial reconstruction zoomed in to see the vessel in close detail :

As you can see, there are a collection of small channels that likely represent vasa vasorum that have collateralized antegrade flow due to the patient’s prior right ICA occlusion. At certain locations, the vasa vasorum appears to collateralize back to the native vessel. This does not appear to be intraluminal thrombus.

Given the patient stability over 1 year, we recommended no further endovascular or surgical management.