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
Carotid body may involve mitochondrial oxygen sensors and the haem-containing cytochromes that undergo reversible one-electron reduction during oxidative-phosphorylation. Haem reversibly binds O with an affinity similar to that of the carotid body, suggesting that haem containing proteins may have a role in O, potentially this could be one of the complexes involved in oxidative-phosphorylation. This leads to increases in reactive oxygen species and rises in intracellular Ca. However, whether hypoxia leads to an increase or decrease in reactive oxygen species is unknown. The role of reactive oxygen species in hypoxia sensing is also under question. The oxygen dependent enzyme haem-oxidase has also