Carotid stenting dilation and cerebral angiography. Carotid stenting is the preferred therapy for patients who are at an increased risk with carotid surgery. High risk factors include medical comorbidities (severe heart disease, heart failure, severe lung disease, age > 75/80, etc.) and anatomic features (contralateral carotid occlusion, radiation therapy to the neck, prior ipsilateral carotid artery surgery, intra-thoracic or intracranial carotid disease) that make surgery difficult or risky. Anatomic high surgical risk: Co-morbid high surgical risk: Using the criteria of successful trials, candidates are either symptomatic (TIA or stroke) patients with >50% stenosis of the carotid artery, or are asymptomatic with >80%
Carotid endarterectomy (CTA) or invasive angiography. Revascularization of symptomatic stenoses has a much higher therapeutic index compared to asymptomatic lesions. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) are both large randomized class 1 studies which have helped define current indications for carotid endarterectomy in symptomatic patients. The NASCET found that for every six patients treated, one major stroke would be prevented at two years (i.e. a number needed to treat (NNT) of six) for symptomatic patients with a 70–99% stenosis, where percent stenosis was defined as: Symptomatic patients with less severe carotid occlusion (50–69%)