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%
Intima-media thickness not satisfactory. IMT can be measured using external ultrasound in large arteries relatively close to the skin (e.g. the carotid, brachial, radial, or femoral arteries). External ultrasound methods have the advantage of being non-invasive, comparatively low cost and convenient. Deeper internal arteries, such as the coronary arteries require special intravascular catheters employing ultrasound or optical coherence tomography to measure IMT. The carotid artery is the usual site of measurement of IMT and consensus statements for carotid IMT have been published for adults and children. Often, IMT is measured in three locations: in the common carotid artery (typically at one cm