When is revascularization indicated for internal carotid artery (ICA) stenosis?

When to Revascularize Internal Carotid Artery Stenosis

Revascularize symptomatic ICA stenosis ≥70% with carotid endarterectomy (CEA) within 14 days of symptom onset, provided perioperative stroke/death risk is <6%; for asymptomatic stenosis ≥60-70%, revascularization should only be considered in highly selected patients with high-risk features, life expectancy >5 years, and perioperative risk <3%. 1

Symptomatic ICA Stenosis (Recent TIA or Stroke within 6 Months)

Strong Indications for Revascularization

For symptomatic stenosis ≥70-99%:

• CEA is recommended as the primary intervention with documented perioperative stroke/death rates <6% 1
• Timing is critical: perform revascularization within 14 days of the index event to maximize benefit and reduce recurrent stroke risk 1, 2
• The benefit increases with stenosis severity, with maximal benefit at 70-99% stenosis 1

For symptomatic stenosis 50-69%:

• CEA should be considered, but the benefit is more modest and depends on patient-specific factors including age, sex, comorbidities, and plaque characteristics 1
• Male patients, those >75 years, hemispheric symptoms (versus retinal), cortical strokes, irregular stenosis, and contralateral occlusion predict higher benefit from intervention 1

For symptomatic stenosis <50%:

• Revascularization is not recommended—no benefit demonstrated and may increase stroke risk 1

Important Caveats for Symptomatic Patients

• Near-occlusion lesions (95-99% with distal ICA collapse or "trickle flow") do not benefit from surgery despite high-grade stenosis 1
• Avoid CEA within the first 48 hours after symptom onset due to increased risk of hemorrhagic transformation 1
• All symptomatic patients require optimal medical therapy (OMT) regardless of revascularization decision 1

Asymptomatic ICA Stenosis

Limited Indications for Revascularization

The threshold for asymptomatic revascularization is much higher because modern medical therapy has reduced annual stroke risk to ≤1% per year 3

Consider revascularization only when ALL of the following criteria are met:

• Stenosis ≥60-70% by NASCET criteria 1
• Life expectancy >5 years 1
• Documented institutional perioperative stroke/death rate <3% 1
• Presence of high-risk features (see below) 1

High-risk features that may justify intervention in asymptomatic patients:

• Age >75 years 1
• Male sex 1
• Bilateral 70-99% stenosis or contralateral occlusion 1
• Ipsilateral silent cerebral infarction on imaging 1
• Rapid progression of stenosis (≥2 categories in 1 year) 3
• Irregular or ulcerated plaque morphology 1

Revascularization is NOT recommended for asymptomatic patients:

• Without high-risk features 1
• With life expectancy <5 years 1
• When institutional perioperative complication rates exceed 3% 1

Choice of Revascularization Method: CEA vs CAS

CEA is Preferred in Most Cases

CEA should be the default choice for:

• All symptomatic patients who are average surgical risk 1, 4
• Patients >70 years of age (CAS has higher complication rates in elderly) 2, 4
• Asymptomatic patients when intervention is indicated 1

CAS May Be Considered When:

For symptomatic patients:

• High surgical risk due to severe medical comorbidities 1, 4
• Hostile neck anatomy (post-radiation stenosis, restenosis after prior CEA, high cervical lesions, tracheostomy, contralateral laryngeal nerve palsy) 1, 4
• Age <70 years with appropriate anatomy 5

For asymptomatic patients:

• CAS may be considered in high surgical risk patients with high-risk features, but evidence is weaker (Class IIb recommendation) 1

Operator Experience Requirements

• CEA teams must achieve <6% perioperative stroke/death in symptomatic patients and <3% in asymptomatic patients 1
• CAS operators should have established periprocedural morbidity/mortality rates of 4-6% for symptomatic patients 1
• Low-volume operators have significantly higher complication rates, particularly with CAS 1

Antiplatelet Therapy Management

For Symptomatic Patients Not Immediately Revascularized:

• Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel 75mg is mandatory for at least 21 days to reduce early recurrent stroke risk 1, 2
• DAPT may be extended up to 90 days considering bleeding risk 1
• This reduces asymptomatic cerebral embolization and stroke recurrence after minor stroke/TIA 1

Perioperative Antiplatelet Management:

For CEA:

• Continue aspirin perioperatively 1
• Clopidogrel can be stopped after surgery 1

For CAS:

• DAPT with aspirin and clopidogrel is required before the procedure 1, 2
• Continue DAPT for at least 1 month (preferably 4 weeks) after CAS 1
• This requirement may delay elective cardiac surgery by 4-5 weeks if CAS is performed first 1

Long-term Antiplatelet Therapy:

• Single antiplatelet therapy (aspirin or clopidogrel) should be continued lifelong after any carotid revascularization 1, 2, 3

Special Populations

Patients Undergoing Cardiac Surgery (CABG):

• Screen with carotid duplex ultrasound if: history of stroke/TIA, carotid bruit, multivessel CAD, peripheral arterial disease, or age >70 years 1
• For symptomatic stenosis 70-99% or 50-99% in men: carotid revascularization is recommended before or concurrent with CABG 1
• For asymptomatic unilateral stenosis: perform isolated CABG—concomitant carotid revascularization provides minimal benefit (1% per year risk reduction) 1
• Timing of procedures (synchronous vs staged) should target the most symptomatic territory first 1

Common Pitfalls to Avoid

1. Do not revascularize symptomatic stenosis <50%—no benefit and potential harm 1
2. Do not operate on near-occlusion lesions with distal collapse—these do not benefit despite appearing severe 1
3. Do not delay revascularization beyond 14 days in symptomatic patients—benefit decreases significantly with time 1, 2
4. Do not routinely revascularize asymptomatic stenosis—modern medical therapy alone achieves ≤1% annual stroke risk 3
5. Do not perform CAS in patients >70 years as first choice—higher complication rates compared to CEA 2, 4
6. Do not proceed if institutional complication rates exceed guideline thresholds (6% symptomatic, 3% asymptomatic) 1

Mandatory Optimal Medical Therapy for All Patients

Regardless of revascularization decision, all patients with carotid stenosis require:

• Statin therapy (high-intensity) 1, 3
• Blood pressure control 3
• Diabetes management 3
• Smoking cessation 3
• Antiplatelet therapy (as detailed above) 1, 2

Follow-up Surveillance

• Annual clinical follow-up to assess cardiovascular risk factors and treatment compliance 1, 3
• Duplex ultrasound within first month after revascularization 1, 3
• Annual duplex ultrasound to monitor disease progression 3
• Assess for neurological symptoms at each visit 1