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
Composition of the human body mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life. The remaining elements are trace elements, of which more than a dozen are thought on the basis of good evidence to be necessary for life. All of the mass of the trace elements put together (less than 10 grams for a human body) do not add up to the body mass of magnesium, the least common of the 11 non-trace elements.