[Angiographic assessment of collateral circulation pathways in the stenosis and occlusion of the extracranial cerebral arteries].

Visualization in angiographic investigations of the common carotid artery of certain collateral circulation routes can sometimes facilitate evaluation of the site of occlusion and its extent. Collateral circulation via the arterial network of the nape of the neck indicates stenosis or occlusion of the subclavian artery. Collateral circulation through the muscular branches of the occipital artery to the vertebral and basal arteries suggests lesions in the vertebral artery. Collateral circulation via the anterior communicating artery suggests stenosis or occlusion of the contralateral internal carotid artery. Visualization in the angiograms of the common carotid artery of numerous channels of collateral circulation indicates presence of disseminated changes in the extracranial brain-supplying arteries.