Arterial Stenosis or Occlusion Indicated by String Sign
Clinical Significance and Management
- The American College of Cardiology indicates that a string sign is most commonly associated with Class IIa or IIb acute limb ischemia, requiring prompt intervention 1, 2
- The Rutherford classification categorizes limbs with a string sign as "salvageable/marginally threatened" (Category IIa) or "salvageable/immediately threatened" (Category IIb) 1, 4
- The American College of Cardiology recommends revascularization to be performed emergently (within 6 hours) for immediately threatened limbs showing a string sign 3, 5
- Initial management includes systemic anticoagulation with heparin while preparing for definitive treatment, as recommended by the American College of Cardiology and the European Heart Journal 2, 6
Diagnostic and Treatment Approach
- Additional imaging (CTA or MRA) may be warranted when a string sign is detected, particularly in patients with complex vascular history, as suggested by the American College of Cardiology 3
- The revascularization strategy depends on local resources, patient factors, and degree of ischemia, with options including catheter-directed thrombolysis, percutaneous mechanical thrombectomy, or surgical intervention, according to the American College of Cardiology 2, 3, 5, 6
- The American College of Cardiology and the European Heart Journal recommend selecting the technique that provides the most rapid restoration of arterial flow with the least risk 5
- For viable limbs with a string sign, revascularization should be performed urgently (within 6-24 hours), while immediately threatened limbs require emergency intervention (within 6 hours), as recommended by the American College of Cardiology and Circulation 5, 7