Acute Ischemic Stroke and Mechanical Thrombectomy

Recognizing stroke: every minute matters

Stroke symptoms usually begin suddenly. Warning signs can include:

• Sudden weakness or numbness of the face, arm, or leg, particularly on one side of the body
• Sudden facial asymmetry or a drooping face
• Sudden trouble speaking, slurred speech, or difficulty understanding language
• Sudden loss of vision, double vision, or a field-of-vision deficit
• Sudden severe imbalance, dizziness, inability to walk, or loss of coordination
• Sudden confusion, altered awareness, or unusual sleepiness
• Sudden severe headache, particularly if associated with neurologic symptoms

A useful public mnemonic is BE FAST:

• B — Balance: sudden loss of balance or coordination
• E — Eyes: sudden vision loss or double vision
• F — Face: facial droop or asymmetry
• A — Arm: new arm or leg weakness or numbness
• S — Speech: slurred speech, inability to speak, or difficulty understanding
• T — Time: call 911 immediately

What is mechanical thrombectomy?

Mechanical thrombectomy is a catheter-based procedure through a very small puncture, commonly in the wrist or groin, a physician guides thin catheter through the arteries to the blocked vessel in the brain. Using X-ray guidance, the clot is removed.

The two most common technical approaches are:

• Stent retriever thrombectomy: A small, self-expanding mesh device is deployed through or into the clot, engages the clot, and is withdrawn through the catheter.
• Aspiration thrombectomy: A large-bore catheter is advanced to the clot and controlled suction is used to aspirate the clot.

In many procedures, these techniques are used together or sequentially. The procedural goal is to restore blood flow rapidly while protecting the downstream brain circulation.

Thrombolytic medication and thrombectomy

Some patients are eligible for intravenous thrombolytic medication, This medication is administered through a vein and can dissolve or soften some clots.

When a large-vessel occlusion is identified, thrombectomy may be needed to physically remove the clot.

Who may be a candidate for mechanical thrombectomy?

Candidates can be identified through an emergency evaluation that commonly includes neurologic examination, noncontrast CT of the head, vascular imaging, and in selected cases perfusion imaging or MRI.

Factors that may support thrombectomy include:

• A disabling neurologic deficit.
• Imaging evidence of a large-vessel occlusion.
• A pattern of brain injury and potentially salvageable tissue that supports intervention.
• A clinical and medical profile in which the anticipated benefit outweighs procedural risk.
• Treatment within an evidence-supported time window, including selected patients up to 24 hours from last known well.

Patients who may be considered include those with:

• Internal carotid artery or proximal middle cerebral artery occlusion.
• Selected posterior-circulation strokes, including basilar artery occlusion.
• Wake-up or unknown-onset stroke with favorable imaging.
• Selected larger-core infarcts based on contemporary randomized data and guideline-informed criteria.

What to expect during thrombectomy

A small access site is created in an artery, commonly in the wrist or groin. Catheters are navigated through the arterial system to the brain. The clot is engaged with aspiration, a stent retriever, or a combined technique. Repeated angiographic images confirm whether blood flow has been restored.

The procedure time varies depending on the anatomy, clot location, vascular tortuosity, and number of passes required.