Vasa Vasorum: Another Cause of the Carotid String Sign

Abstract

BACKGROUND AND PURPOSE: Our purpose was to describe a variant of the carotid string sign that may be associated with a completely occluded vessel and to consider possible pathophysiological mechanisms for this observation.

METHODS: Carotid angiography was performed in three patients with suspected carotid stenosis and in a fourth with carotid dissection. Surgery was performed in one of the patients with carotid stenosis.

RESULTS: On all angiograms, instead of a single linear or curvilinear contrast “string,” either single or multiple serpiginous channels were seen. In one case, such a channel was seen emanating from below the origin of an occluded internal carotid stump, reconstituting the distal portion of the vessel. Surgery revealed a completely occluded lumen with a small intramural vessel bypassing the obstruction.

CONCLUSION: We propose that these channels are either atherosclerotically induced neovessels connecting bridging vasa vasorum or recanalized luminal thrombus. We review the literature associated with this subject.