What is the recommended approach for Large Vessel Occlusion (LVO) in the setting of a stroke when systemic thrombolytics are contraindicated?

Management of Large Vessel Occlusion (LVO) Stroke When Systemic Thrombolytics Are Contraindicated

Proceed directly to endovascular thrombectomy (EVT) with mechanical thrombectomy for patients with LVO stroke when systemic thrombolytics are contraindicated—this is a reasonable and evidence-based approach that can achieve excellent outcomes independent of IV thrombolysis. 1

Initial Imaging Protocol

When systemic thrombolytics are contraindicated, your imaging workflow should focus on rapid LVO detection and thrombectomy eligibility:

• Obtain non-contrast CT head immediately to exclude intracranial hemorrhage and assess ASPECTS score (Alberta Stroke Program Early CT Score) 1
• Proceed directly to CT angiography (CTA) or multiphase CTA (mCTA) to identify LVO and assess collateral circulation 1
• For patients presenting within 0-6 hours: If ASPECTS ≥6 and LVO is confirmed, proceed directly to thrombectomy without additional perfusion imaging 1
• For patients presenting 6-24 hours from last known well: Consider CT perfusion (CTP) or MRI with diffusion-weighted imaging (DWI) to assess core infarct size and penumbra, though some centers proceed with mCTA alone if collaterals are favorable 1

Direct-to-Angiography Approach

In highly selected cases where LVO is strongly suspected and thrombolytics are contraindicated:

• Consider proceeding directly to catheter angiography after non-contrast CT in patients with clear signs of LVO (e.g., hyperdense middle cerebral artery sign) and known etiology (e.g., new-onset atrial fibrillation) 1
• This approach minimizes time to reperfusion by allowing immediate conversion from diagnostic angiogram to therapeutic thrombectomy 1

Thrombectomy Eligibility Criteria

Anterior Circulation LVO (0-6 hours)

• NIHSS ≥6 (though lower scores with disabling deficits may be considered) 1
• ASPECTS ≥6 on non-contrast CT 1
• Confirmed LVO on CTA (internal carotid artery, M1, or proximal M2 segment) 1

Anterior Circulation LVO (6-24 hours)

• ASPECTS ≥6 and favorable perfusion imaging (small core, significant penumbra) 1
• Intermediate to good collaterals on mCTA 1
• Consider patient age, baseline functional status, and other prognostic factors in a Bayesian framework 1

Posterior Circulation LVO (Basilar Artery)

• Within 0-12 hours: Thrombectomy is recommended (Class I, Level B-R) if NIHSS ≥6 and PC-ASPECTS ≥6 1
• Between 12-24 hours: Thrombectomy is reasonable (Class IIa, Level B-R) with same criteria 1
• Beyond 24 hours: May be considered on case-by-case basis (Class IIb, Level C-EO) 1
• Recent ATTENTION and BAOCHE trials demonstrated 46% good functional outcome (mRS 0-3) with thrombectomy versus 23-24% with medical therapy alone 1

Thrombectomy Techniques

Both stent retrievers and aspiration thrombectomy are reasonable first-line approaches:

• Stent retrievers (Solitaire FR, Trevo) are generally preferred over older coil retrievers (Merci) 1, 2
• Aspiration thrombectomy (Penumbra System) is equally reasonable as first-line therapy 1, 2
• Combined techniques may be used if initial approach fails 1, 2

Critical Time Considerations

Time is brain—up to 2 million neurons are lost per minute during LVO stroke: 1

• Avoid delays from unnecessary perfusion imaging in clear thrombectomy candidates presenting within 6 hours 1
• The benefit of EVT extends up to 24 hours in selected patients, but earlier reperfusion correlates strongly with better outcomes 1
• In patients without thrombolytic eligibility, the urgency shifts entirely to rapid LVO detection and thrombectomy 1

Adjunctive Interventions

If mechanical thrombectomy alone is insufficient:

• Intra-arterial thrombolysis may be considered if mechanical revascularization fails, though this is off-label use of rtPA 1
• Angioplasty and stenting may be considered for persistent severe stenosis after thrombectomy, particularly with poor reperfusion or high re-occlusion risk 1

Common Pitfalls to Avoid

• Do not delay thrombectomy to obtain perfusion imaging in patients presenting within 6 hours with clear LVO and ASPECTS ≥6 1
• Do not rely solely on NIHSS score to determine LVO presence—correlation is poor due to collateral variability and stroke mimics 1
• Do not extrapolate basilar artery data to distal posterior circulation vessels (e.g., PICA)—these lack robust evidence for thrombectomy 3
• Do not assume futility based on time alone—patients up to 24 hours may benefit with appropriate imaging selection 1

Expected Outcomes

When thrombolytics are contraindicated, thrombectomy alone achieves:

• Successful recanalization (mTICI 2b/3) in 70-90% of cases 1
• Good functional outcome (mRS 0-3) in 40-50% of appropriately selected patients 1, 2
• Symptomatic intracranial hemorrhage rates of 5-8%, comparable to combined IV thrombolysis plus thrombectomy 1, 2