Carotid stenting stenosis of the internal carotid artery. Carotid stenting may be considered an alternative to carotid surgery in average surgical risk patients, albeit with a higher risk of death or stroke as seen in the SAPPHIRE and CREST trials. Features that favor carotid stenting include non-atherosclerotic cause of the stenosis (fibrodysplasia, radiation, early post-surgical stenosis or flap) an experienced center and experienced physician performing the procedure. Features that make stent placement more difficult include significant aortic arch tortuosity, thrombus containing lesions, occluded carotid artery, heavily calcified vessels, symptomatic patients and very tortuous and twisting vessels. None of these affect open, surgical
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