From the Guidelines
Carotid artery occlusion presents with several characteristic clinical features that vary depending on the severity and location of the blockage, including sudden onset of neurological deficits, amaurosis fugax, and carotid bruit, with symptoms ranging from mild to severe and potentially causing major stroke with permanent disability 1. The clinical presentation of carotid artery occlusion can be diverse, but common features include:
- Sudden onset of neurological deficits affecting the contralateral side of the body, such as hemiparesis, hemisensory loss, facial droop, dysarthria, and aphasia if the dominant hemisphere is affected
- Amaurosis fugax, which is temporary monocular blindness, may occur when emboli from the carotid artery travel to the ophthalmic artery
- Some patients may report a preceding history of transient ischemic attacks (TIAs) with similar but temporary symptoms
- On examination, a carotid bruit may be auscultated over the affected artery, though its absence doesn't rule out significant stenosis The underlying pathophysiology involves atherosclerotic plaque formation leading to stenosis and eventual occlusion, or thromboembolism where clots form at the site of stenosis and travel distally to block smaller cerebral vessels 1. Immediate medical attention is crucial, as treatments including antiplatelet therapy, anticoagulation, and potential surgical interventions like carotid endarterectomy or stenting are time-sensitive and can prevent permanent neurological damage if implemented promptly 1. It's essential to note that the severity of stenosis is defined according to angiographic criteria, and imaging of the extracranial carotid arteries should be performed whenever cerebral ischemia is a suspected mechanism of neurological symptoms in a viable patient 1. The choice of treatment depends on the severity of stenosis, the presence of symptoms, and the patient's overall health status, with carotid endarterectomy being recommended for symptomatic patients with 70% to 99% stenosis, and carotid artery stenting being considered for patients with significant comorbidities or anatomical factors that make endarterectomy high-risk 1.
From the Research
Clinical Features of Carotid Artery Occlusion
- Carotid artery occlusion is associated with high rates of morbidity and mortality, and can present with recurrent strokes 2
- The clinical presentation of acute and chronic internal carotid artery occlusion (ICAO) can vary, with acute ICAO often presenting with severe symptoms and chronic ICAO presenting insidiously with recurrent strokes 2
- Carotid stenosis, which can lead to occlusion, is generally associated with high risks of stroke and vascular events 3
- Near-occlusion, a critical point beyond which further increase in stenosis no longer allows sufficient blood to pass through to maintain volumetric flow, can also increase the risk of stroke 4
Management and Treatment
- Surgical, endovascular, or a combination (hybrid) revascularization has been shown to be effective in recanalization with improved functional outcomes in patients with ICAO 2
- Antiplatelet therapy, such as aspirin and clopidogrel, is often used to prevent vascular events in patients with carotid stenosis, including those with near-occlusion 3, 5, 6
- The optimal management of near-occlusion remains a matter of debate, with some studies suggesting a small benefit of carotid endarterectomy or stenting compared to medical treatment in patients with near occlusion 4
Risk Factors and Prevention
- Cardiovascular comorbidities, such as unstable angina, can increase the risk of vascular events in patients with carotid stenosis 5
- Lifestyle modifications, such as stopping smoking and monitoring hypertension, hyperlipidemia, and diabetes, can help control the processes associated with atheroma and reduce the risk of embolic events 3
- Dual antiplatelet therapy with clopidogrel and aspirin has been shown to be effective in reducing the risk of ischemic events in patients undergoing carotid artery stenting 5