When should vascular intervention be done in a patient with a thrombosed right internal carotid artery (ICA) and frontal lobe stroke?

Timing of Vascular Intervention for Thrombosed Internal Carotid Artery with Frontal Lobe Stroke

For a patient with acute thrombosed right internal carotid artery and frontal lobe stroke, mechanical thrombectomy should be performed within 6 hours of symptom onset if the patient meets eligibility criteria, or up to 6-24 hours if advanced imaging demonstrates salvageable tissue with favorable perfusion mismatch. 1

Immediate Assessment and Time-Critical Decision Making

The most critical factor is determining the exact time of symptom onset, defined as when the patient was last at their neurological baseline 2. This determines your intervention window and guides all subsequent decisions.

Within 0-6 Hours of Symptom Onset

Mechanical thrombectomy is strongly recommended if ALL of the following criteria are met: 1

• Age ≥18 years
• Pre-stroke modified Rankin Scale (mRS) score of 0-1 (functionally independent)
• Causative occlusion of the internal carotid artery documented on CTA
• NIHSS score ≥6 (moderate to severe deficit)
• ASPECTS ≥6 (limited infarct core on CT)
• Treatment can be initiated (groin puncture) within 6 hours of last known well

Do not delay thrombectomy to assess response to IV thrombolysis - proceed directly to catheter angiography if mechanical thrombectomy is planned 1. The presence of cervical ICA occlusion in addition to intracranial large vessel occlusion does not preclude mechanical thrombectomy and can be considered for intervention 1.

Within 6-24 Hours of Symptom Onset (Extended Window)

Mechanical thrombectomy is recommended if advanced imaging demonstrates salvageable tissue: 1

• Perform CTP or DW-MRI with or without perfusion imaging 1
• Proceed with thrombectomy if there is sizable mismatch between ischemic core (by CTP or MRI-DWI) and either clinical deficits or area of hypoperfusion (by CTP or MRI-PWI) 1
• The DEFUSE 3 trial demonstrated that patients with proximal ICA occlusion treated 6-16 hours after last known well had significantly better functional outcomes (45% vs 17% functional independence) when selected by perfusion imaging showing initial infarct <70 ml and perfusion-to-infarct ratio ≥1.8 3

Adjunctive IV Thrombolysis

Administer IV alteplase (0.9 mg/kg, maximum 90 mg) if the patient presents within 4.5 hours of symptom onset and has no contraindications, even if mechanical thrombectomy is planned 1. Key requirements:

• Blood glucose must be assessed before initiating alteplase 1
• Blood pressure must be lowered below 185/110 mmHg before thrombolysis 1
• Do not wait to evaluate thrombolysis response before proceeding to thrombectomy 1

Critical Contraindications to Acute Intervention

Do NOT perform carotid revascularization in the following situations: 1

• Chronic total occlusion of the carotid artery (not acute thrombosis) 1
• Severe disability from cerebral infarction that precludes preservation of useful function 1
• Large established infarct with hemorrhagic transformation on initial CT 2
• Significant alteration in level of consciousness suggesting massive infarction 4

Technical Goals and Approach

The technical goal of mechanical thrombectomy should be reperfusion to modified TICI grade 2b/3 1. Use stent retriever or direct aspiration techniques 1. When cervical ICA occlusion is present with intracranial extension, the intervention becomes more complex and may require combined cervical and intracranial approaches 5, 6.

Special Timing Considerations for Surgical Thrombectomy

While endovascular thrombectomy is the primary intervention, surgical carotid thromboemdarterectomy has been reported in highly selected cases when performed within 6 hours of symptom onset in patients without major consciousness disturbances or hemorrhagic infarction 4. However, this approach is rarely used in modern practice given the superiority and availability of endovascular techniques.

Common Pitfalls to Avoid

• Do not delay intervention for extensive additional imaging if the patient is within the 6-hour window and meets clinical criteria 1
• Do not withhold thrombectomy based solely on cervical ICA involvement - combined cervical and intracranial occlusions can be treated 1
• Do not attempt intervention beyond 24 hours without exceptional circumstances and multidisciplinary discussion 1
• Do not proceed with intervention if delay to revascularization exceeds 6 hours in patients with deteriorating consciousness - mortality risk increases substantially 4

Post-Intervention Management

After successful recanalization, maintain blood pressure below 180/105 mmHg for at least 24 hours 2. Monitor closely for hemorrhagic transformation and reperfusion injury 2. Initiate dual antiplatelet therapy if not already administered 1.