Internal carotid artery stenosis: Natural history and management

Extracranial internal carotid artery stenosis is an important cause of ipsilateral stroke. The natural history of the disease is related to the presence or absence of ipsilateral hemispheric symptoms and the severity of stenosis. Doppler ultrasound is commonly used as a screening test, with more advanced noninvasive imaging studies such as computerized tomography angiography (CTA) and magnetic resonance angiography (MRA) utilized as confirmatory tests if invasive treatment is contemplated. With less-invasive imaging techniques, traditional catheter angiography is rarely indicated for the diagnosis of carotid stenosis. Medical therapy remains the mainstay of treatment in patients with asymptomatic stenosis. Invasive treatment of asymptomatic internal carotid artery stenosis is indicated in a selected group of patients with severe stenosis and life expectancy exceeding 5 years. Invasive treatment is indicated for symptomatic patients with stenosis greater than 70% and in selected patients with recent symptoms and moderate (50% to 69%) stenosis. The risk of ipsilateral stroke is highest in the first few weeks following a presenting symptomatic event. Therefore, when indicated, invasive treatment of symptomatic disease should be considered soon after presenting symptoms to maximize the benefit of the procedure. Carotid endarterectomy (CEA) remains the gold standard for invasive treatment of internal carotid artery disease (symptomatic and asymptomatic). However, based on recent evidence, carotid angioplasty and stenting (CAS) is a valid alternative to CEA in an increasing percentage of patients in need of invasive treatment. Regardless of treatment modality, proper patient selection for invasive treatment remains the single most important factor to insure proper use of available technology.