Carotid String Sign: Is There a Role for Carotid Stenting?

Objectives: Carotid string sign has been considered an unfavorable lesion and relative contraindication for carotid angioplasty and stenting(CAS). Difficulty or inability to advance an embolic protection device through a near-occlusive lesion, possible stent collapse and the need of unprotected predilatation have been considered adverse circumstances for CAS. The purpose of this study was to assess the feasibility and safety of CAS for carotid string sign.
Methods: We studied 13 patients with carotid string sing that underwent CAS under cerebral embolic protection. Our clinical results, interventional techniques, periprocedural complications and follow-up outcomes are reported.
Results: Eight patients(62%) were symptomatic. Technical success was 100%. Predilatation was required in 10 patients(77%). Initially, a filter device (FilterWireEZ, Boston Scientific, Natick, MA) was used in 4 cases(31%) for embolic protection. Two of these patients required unprotected predilatation. Later, all lesions were crossed and treated under complete proximal embolic protection. Proximal balloon occlusion (MoMa, Invatec, Roncadelle, Italy) was used in 8 cases(62%) and flow reversal (GORE Neuro-Protection System, W.L. Gore & Associates, Flagstaff, AZ) in 1(8%). After balloon dilatation, a normal caliber internal carotid artery beyond the lesion was seen angiographically in all cases. Closed-cell stents were used in 6 cases(46%), open-cell stents in 5 cases(39%) and hybrid stents in 2(5%). No periprocedural transient ischemic attacks, strokes or deaths occurred at 30 days. The median follow up period was 12 months (interquartile range,7-21 months). One stent occlusion occurred 6 months after CAS that did not result in a neurologic deficit. Neither in-stent restenosis nor ipsilateral strokes occurred during follow-up. Two patients died 12 and 24 months after CAS of unrelated causes.

Conclusions: Carotid string sign may be treated with carotid stenting with favorable periprocedural and early results. Because of the frequent need of predilatation and possible inability to advance a filter device without previous unprotected predilatation, either proximal balloon occlusion or flow reversal devices may be favored as these may effectively provide cerebral embolic protection throughout the entire CAS procedure.