Collateral failure? Late mechanical thrombectomy after failed intravenous thrombolysis

Area of Science:

• Neurology
• Vascular Medicine
• Neurocritical Care

Background:

• Collateral circulation plays a vital role in acute ischemic stroke by compensating for reduced blood flow.
• The endurance and quality of collateral perfusion can vary significantly among patients.
• Collateral failure can lead to progressive ischemia and clinical deterioration, even after initial compensation.

Observation:

• A patient with a persistent left middle cerebral artery occlusion showed initial improvement after intravenous thrombolysis.
• The patient later deteriorated but recovered following mechanical thrombectomy nearly 14 hours after symptom onset.
• This case highlights the dynamic nature of collateral function in stroke.

Findings:

• Early clinical changes in acute ischemic stroke may reflect collateral perfusion status rather than recanalization or reocclusion.
• The concept of 'collateral failure' needs refinement to account for the expected role and endurance of these compensatory pathways.
• Delayed collateral failure can potentially extend the therapeutic window for revascularization procedures.

Implications:

• Investigating collateral pathophysiology may identify predictive clinical or imaging biomarkers for stroke outcomes.
• Understanding collateral function could lead to novel therapeutic approaches to enhance revascularization efficacy.
• This case underscores the importance of considering collateral status in managing acute ischemic stroke patients beyond standard time windows.