What is the management of atheromatous plaques causing severe stenosis of the internal carotid artery?

Management of Severe Stenosis of the Proximal Left Internal Carotid Artery Due to Atheromatous Plaques

For patients with severe stenosis of the proximal left internal carotid artery caused by atheromatous plaques, carotid revascularization (either carotid endarterectomy or carotid artery stenting) is strongly recommended, particularly for symptomatic patients with stenosis >50% and asymptomatic patients with stenosis >60-70% who have high-risk plaque features. 1

Risk Stratification

Risk stratification is essential for determining the appropriate management strategy:

• Symptomatic carotid stenosis (recent stroke or TIA within past 2 weeks): Revascularization is beneficial for stenosis >50% 1
• Asymptomatic carotid stenosis: Consider revascularization for stenosis >60-70% with high-risk plaque features 1, 2
• Risk factors that increase stroke risk: Plaque morphology (intraplaque hemorrhage, inflammation, ulceration), plaque progression, and embolic signals 1

Diagnostic Evaluation

Accurate assessment of stenosis severity is crucial for management decisions:

• Duplex ultrasound (DUS): First-line investigation - identifies stenosis but has limitations in precise determination of moderate-to-high-grade stenosis 1
• Cross-sectional angiography: CT angiography (CTA) or magnetic resonance angiography (MRA) provide more accurate assessment and can image the cerebral circulation 1
• Plaque morphology assessment: MRI can detect intraplaque hemorrhage (IPH), which is a strong predictor of stroke risk (HR 10.2 for symptomatic and HR 7.9 for asymptomatic patients) 1
• Advanced imaging: 18F-FDG PET can detect plaque inflammation, which is associated with symptomatic disease 1

Management Options

1. Medical Therapy (Always Warranted)

All patients with carotid stenosis should receive optimal medical therapy:

• Antiplatelet therapy: Daily aspirin (75-325 mg) 3
• Lipid-lowering therapy: High-intensity statins 1, 2
• Blood pressure control: ACE inhibitors preferred 2
• Lifestyle modifications: Smoking cessation, diet optimization, physical activity 4

2. Carotid Endarterectomy (CEA)

CEA is indicated for:

• Symptomatic patients: With stenosis >50% 1, 2
• Asymptomatic patients: With stenosis >60% and high-risk features 1, 5
• Timing: Early intervention (within 2 weeks) for symptomatic patients provides greatest benefit 1
• Perioperative risk: Should be <3% for asymptomatic and <6% for symptomatic patients 5

3. Carotid Artery Stenting (CAS)

CAS is an alternative to CEA:

• Indications: Similar to CEA - symptomatic stenosis >50% and asymptomatic stenosis >60% 1, 2
• Cerebral protection: Proximal protection systems are superior to distal filters in reducing cerebral embolization 1
• Second-generation stents: Provide better plaque sequestration than first-generation stents 1
• Considerations: May be preferred in patients with high surgical risk, previous neck radiation, or difficult surgical access 2

Special Considerations

• Hospital factors: Outcomes are better in larger hospitals with dedicated intensive care units and experienced specialists 1
• Multidisciplinary approach: Collaboration between neurology, vascular surgery, cardiology, and interventional radiology improves outcomes 1
• Plaque vulnerability markers: Features like intraplaque hemorrhage, thin/ruptured fibrous cap, and inflammation increase stroke risk independent of stenosis severity 1, 6

Common Pitfalls to Avoid

• Delayed intervention: For symptomatic patients, benefit of revascularization diminishes with time after the initial event 1
• Overreliance on stenosis degree alone: Plaque morphology and vulnerability features are important risk factors independent of stenosis severity 1
• Inadequate imaging: Using only DUS without confirmatory cross-sectional imaging may lead to inaccurate assessment of stenosis severity 1
• Underestimating associated risks: Patients with carotid stenosis often have higher risk of myocardial infarction than stroke 1
• Overlooking eye symptoms: Transient monocular blindness (amaurosis fugax) may indicate carotid stenosis and requires urgent evaluation 3