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 body been put forward as a hypoxia sensor. In normoxia, haem-oxygenase generates carbon monoxide (CO), CO activates the large conductance calcium-activated potassium channel, BK. Falls in CO that occur as a consequence of hypoxia would lead to closure of this potassium channel and this would lead to membrane depolarisation and consequence activation of the carotid body. A role for the "energy sensor" AMP-activated protein kinase (AMPK) has also been proposed in hypoxia sensing. This enzyme is activated during times of net energy usage and metabolic stress, including hypoxia. AMPK has a number of targets and it appears that, in the carotid