Carotid endarterectomy benefits and risks of the procedure is required on an individual patient basis. Peri-operative CEA risks for combined 30 day mortality and stroke risk should be < 3% for asymptomatic patients and ≤ 6% for symptomatic patients. Symptomatic patients typically have either transient ischemic attack (TIA) or minor stroke, defined as a focal neurologic defect affecting one side of the body, speech, or vision. Asymptomatic patients have narrowing of their carotid arteries, but have not experienced a TIA or stroke. Carotid stenosis is diagnosed with ultrasound doppler studies of the neck arteries, magnetic resonance angiography (MRA) or computed tomography angiography
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