Table 4. Guideline based recommendations for carotid stenting.

	ACC/AHA guidelines (2011)79)	SVS guidelines (2011)82)	ESVS guidelines (2009)81)	ESC guidelines (2011)80)
Symptomatic	CAS is indicated as an alternative to CEA for symptomatic patients at average or low risk of complications associated with endovascular intervention when the diameter of the lumen of the internal carotid artery is reduced by more than 70% as documented by noninvasive imaging or more than 50% as documented by catheter angiography and the anticipated rate of periprocedural stroke or mortality is less than 6%. [class I; level of evidence B] It is reasonable to choose CAS over CEA when revascularization is indicated in patients with neck anatomy unfavorable for arterial surgery. [class IIa; level of evidence B]	CAS is preferred over CEA in symptomatic patients with ≥ 50% stenosis and prior ipsilateral operation, tracheal stoma, external beam irradiation resulting in fibrosis of the tissues of the ipsilateral neck, or prior cranial nerve injury and lesions that extend proximal to the clavicle or distal to the C2 vertebral body. [grade II; level of evidence B] CAS is preferred over CEA in symptomatic patients with ≥ 50% stenosis and severe uncorrectable CAD, CHF, or COPD. [grade II; level of evidence C]	The available level I evidence suggests that for symptomatic patients, surgery is currently the best option. [level of evidence A] CAS should be offered to symptomatic patients, if they are at high risk for CEA, in high-volume centres with documented low peri-procedural stroke and death rates or inside an RCT. [level of evidence C]	In symptomatic patients at high surgical risk requiring revascularization, CAS should be considered as an alternative to CEA. [class IIa; level of evidence B] In symptomatic patients requiring carotid revascularization, CAS may be considered as an alternative to CEA in high-volume centres with documented death or stroke rate < 6%. [class IIa; level of evidence B]
Asymptomatic	Prophylactic CAS might be considered in highly selected patients with asymptomatic carotid stenosis (minimum 60% by angiography, 70% by validated Doppler ultrasound), but its effectiveness compared with medical therapy alone in this situation is not well established. [class IIb; level of evidence B]	There are insufficient data to recommend CAS as primary therapy for neurologically asymptomatic patients with 70% to 99% diameter stenosis. Data from CREST suggest that in properly selected asymptomatic patients, CAS is equivalent to CEA in the hands of experienced interventionalists. Operators and institutions performing CAS must exhibit expertise sufficient to meet the previously established American Heart Association guidelines for treatment of patients with asymptomatic carotid stenosis. Specifically, the combined stroke and death rate must be below 3% to ensure benefit for the patient. [grade II; level of evidence B]	It is advisable to offer CAS in asymptomatic patients only in high-volume centres with documented low peri-procedural stroke and death rates or within well-conducted clinical trials. [level of evidence C] CAS is indicated in case of contralateral laryngeal nerve palsy, previous radical neck dissection, cervical irradiation, with prior CEA (restenosis), with high bifurcation or intracranial extension of a carotid lesion, provided that the peri-interventional stroke or death rate is higher than that accepted for CEA. [level of evidence C]	In asymptomatic patients with an indication for carotid revascularization, CAS may be considered as an alternative to CEA in high-volume centres with documented death or stroke rate < 3%. [class IIb; level of evidence B]

ACC, American College of Cardiology; AHA, American Heart Association; SVS, Society for Vascular Surgery; ESVS, European Society for Vascular Surgery; ESC, European Society for Cardiology; CAS, carotid artery stenting; CEA, carotid endarterectomy; CAD, coronary artery disease; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; CREST, Carotid Revascularization Endarterectomy versus Stenting Trial; RCT, randomised clinical trial. Class and grade indicate the strength of the recommendation.