Color flow scan diagnosis of the carotid string sign may prevent unnecessary surgery

Can the color flow scanner assist in the diagnosis and management of patients with preocclusive lesions of the carotid bifurcation (so-called 'string sign')? Twenty-three patients were identified as having a 'string' by duplex criteria. Seventeen patients underwent angiography, which confirmed the duplex findings in 14 patients. In three, the angiogram was originally misread as showing an occluded internal carotid Artery. Six patients were managed solely on the basis of the duplex findings. Based on arteriography and/or duplex criteria, 12 involved internal carotid arteries were not explored. One artery went on to occlude asymptomatically. The remaining 11 have remained patent and asymptomatic (follow-up 6-72 months). Five arteries were predicted operable and underwent successful endarterectomy. Six were predicted inoperable yet underwent exploration. All were ultimately treated by ligation +/- external carotid endarterectomy without subsequent neurological deficit. Duplex scans can identify internal carotid artery string signs, determine operability and may predict the functionally occluded artery that can be safely observed.