In a patient 48 hours after a large left middle cerebral artery infarct with complete occlusion of the left internal carotid artery, is stenting the right carotid artery an appropriate alternative to left carotid stenting?

Stenting the Right Carotid is NOT an Appropriate Alternative to Left Carotid Intervention

In a patient 48 hours post-large left MCA infarct with complete left internal carotid artery occlusion, stenting the contralateral (right) carotid artery does not address the culprit lesion and is not a valid treatment strategy. The right carotid supplies the right hemisphere and cannot compensate for or treat the already-completed left hemispheric infarct caused by the left ICA occlusion. 1, 2

Why This Approach is Fundamentally Flawed

The Culprit Vessel Must Be Addressed

• The left ICA occlusion caused the left MCA territory infarct—this is the vessel that needs evaluation for intervention, not the contralateral side. 3, 1
• Stenting the right carotid would only be relevant if there were symptomatic stenosis on that side causing right hemispheric symptoms, which is not the clinical scenario described. 1, 2

Timing and Acute vs. Chronic Occlusion Distinction

• At 48 hours post-stroke with a completed large infarct, the left ICA occlusion is now considered subacute-to-chronic, and revascularization of a chronic complete ICA occlusion is contraindicated (Class III recommendation). 1, 2
• The American Heart Association explicitly states that chronic complete ICA occlusion is an absolute contraindication to any form of carotid revascularization regardless of symptom status. 1, 2
• Emergency endovascular intervention (thrombectomy with or without stenting) is only appropriate for acute occlusion (symptom onset <6-24 hours) with active neurological deficit and viable cerebral tissue. 3

What Should Actually Be Done

Medical Management is the Only Appropriate Treatment

• Initiate aspirin 81-325 mg daily immediately and continue indefinitely, OR clopidogrel 75 mg daily, OR aspirin plus extended-release dipyridamole 25/200 mg twice daily. 1, 2
• Start high-intensity statin therapy immediately regardless of baseline lipid levels to stabilize atherosclerotic plaque and reduce future stroke risk. 1, 2
• Target systolic blood pressure <140 mmHg and diastolic <90 mmHg, avoiding excessive reduction that could compromise collateral flow. 1, 2

Essential Diagnostic Workup

• Obtain CT angiography or MR angiography of the entire extracranial AND intracranial cerebrovascular system bilaterally to assess collateral circulation and identify other treatable lesions. 1, 2
• This imaging is critical to determine if there are other significant stenoses (including on the right side) that might warrant future intervention for stroke prevention. 1, 2

The Only Scenario Where Right Carotid Intervention Would Be Considered

If Significant Right-Sided Stenosis is Discovered

• If imaging reveals symptomatic stenosis ≥70% on the contralateral (right) carotid artery causing right hemispheric symptoms, carotid endarterectomy may be reasonable if perioperative risk is acceptable. 1, 2, 3
• However, this would be for future stroke prevention on the right side, not for treatment of the already-completed left hemispheric infarct. 1, 4
• The 2024 ESC guidelines recommend CEA over CAS for symptomatic carotid stenosis in low surgical risk patients. 3, 5

Critical Pitfalls to Avoid

• Do not confuse prophylactic treatment of an incidental contralateral stenosis with treatment of the culprit vessel. The right carotid cannot provide retrograde flow to salvage left hemispheric tissue after a completed infarct. 1, 2
• Do not attempt revascularization of the chronic left ICA occlusion—this carries high risk with no proven benefit and is explicitly contraindicated. 1, 2
• Do not delay optimal medical therapy while considering inappropriate interventional options. Medical management is the cornerstone of secondary stroke prevention in this setting. 1, 2

Surveillance and Long-Term Management

• Annual noninvasive imaging (duplex ultrasound, CTA, or MRA) is recommended initially to monitor for progression of contralateral carotid disease and development of new stenotic lesions. 1, 2
• Emphasize medication adherence and risk factor modification (smoking cessation, diabetes control targeting HbA1c <7%, lipid management) as the primary determinants of outcome. 1, 2