Vasa vasorum: Another cause of the carotid string sign

BACKGROUND AND PURPOSE: Our purpose was to describe a variant of the caroti d 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 perf ormed in one of the patients with carotid stenosis. RESULTS: On all angiograms, instead of a single linear or curvilinear contr ast "string," either single or multiple serpiginous channels were seen. In one case, such a channel was seen emanating from below the origin of an occ luded internal carotid stump, reconstituting the distal portion of the vess el. Surgery revealed a completely occluded lumen with a small intramural ve ssel bypassing the obstruction. CONCLUSION: We propose that these channels are either atherosclerotically i nduced neo-vessels connecting bridging vasa vasorum or recanalized luminal thrombus. We review the literature associated with this subject.