What is the treatment for ischemic stroke that utilizes a catheter?

Mechanical Thrombectomy for Ischemic Stroke

Mechanical thrombectomy with stent retrievers is the gold standard treatment for acute ischemic stroke due to large vessel occlusion, and should be initiated (groin puncture) within 6 hours of symptom onset in eligible patients. 1

Patient Selection Criteria

Patients should receive endovascular therapy with a stent retriever if they meet all the following criteria:

• Prestroke modified Rankin Scale (mRS) score 0 to 1
• Acute ischemic stroke receiving intravenous r-tPA within 4.5 hours of onset
• Causative occlusion of the internal carotid artery (ICA) or proximal middle cerebral artery (MCA-M1)
• Age ≥18 years
• NIHSS score of ≥6
• ASPECTS of ≥6
• Treatment can be initiated (groin puncture) within 6 hours of symptom onset 1

Procedural Details

Device Selection

• Stent retrievers are strongly indicated in preference to the older MERCI device (Class I; Level of Evidence A) 1
• The technical goal should be achieving a TICI grade 2b/3 angiographic result (complete or near-complete reperfusion) 1
• The use of a proximal balloon guide catheter or a large-bore distal-access catheter rather than a cervical guide catheter alone may be beneficial (Class IIa) 1

Timing Considerations

• Reduced time from symptom onset to reperfusion is highly associated with better clinical outcomes 1
• Reperfusion should be achieved as early as possible and within 6 hours of stroke onset 1
• Observing patients after intravenous r-tPA to assess for clinical response before pursuing endovascular therapy is NOT required and is NOT recommended 1

Special Situations

1. Beyond 6-hour window: When treatment is initiated beyond 6 hours from symptom onset, the effectiveness of endovascular therapy is uncertain (Class IIb) 1

2. Contraindications to IV r-tPA: In carefully selected patients with anterior circulation occlusion who have contraindications to intravenous r-tPA, endovascular therapy with stent retrievers completed within 6 hours of stroke onset is reasonable (Class IIa) 1

3. Other vessel occlusions: Endovascular therapy may be reasonable for carefully selected patients with occlusion of M2/M3 portions of MCA, anterior cerebral arteries, vertebral arteries, basilar artery, or posterior cerebral arteries (Class IIb) 1

4. Patients with less favorable characteristics: Treatment may be reasonable for patients with prestroke mRS score >1, ASPECTS <6, or NIHSS score <6 with causative occlusion of the ICA or proximal MCA (Class IIb) 1

Adjunctive Treatments

• Patients eligible for intravenous r-tPA should receive it even if endovascular treatments are being considered 1
• Use of salvage technical adjuncts, including intra-arterial fibrinolysis, may be reasonable to achieve better angiographic results if completed within 6 hours of symptom onset 1
• Angioplasty and stenting of proximal cervical atherosclerotic stenosis or complete occlusion at the time of thrombectomy may be considered 1

Complications and Management

Mechanical thrombectomy is associated with several potential complications that need careful monitoring:

• Access-site problems (vessel/nerve injury, hematoma, infection)
• Device-related complications (vasospasm, arterial perforation, dissection)
• Symptomatic intracerebral hemorrhage
• Subarachnoid hemorrhage
• Embolization to new or target vessel territory 2

Systems of Care

1. Patients should be transported rapidly to the closest available certified primary stroke center or comprehensive stroke center 1

2. Regional systems of stroke care should be developed, consisting of:

   • Healthcare facilities that provide initial emergency care, including IV r-tPA
   • Centers capable of performing endovascular stroke treatment with comprehensive periprocedural care 1

3. Primary stroke centers should develop the capability of performing emergency noninvasive intracranial vascular imaging to appropriately select patients for transfer for endovascular intervention 1

Historical Context

Earlier guidelines (2012) suggested against routine use of mechanical thrombectomy (Grade 2C) 1, but multiple positive randomized trials since then have established its efficacy. The 2015 AHA/ASA guidelines now strongly recommend mechanical thrombectomy with stent retrievers for appropriate patients 1.

The evolution from earlier devices like the MERCI Retriever and Penumbra System to modern stent retrievers has significantly improved outcomes, with current devices achieving higher recanalization rates and better functional outcomes 1, 3.

Caution

While mechanical thrombectomy has shown significant benefits in reducing disability and mortality in acute ischemic stroke, patient selection remains critical to maximize benefits and minimize risks. The procedure should be performed by experienced neurointerventionists at centers with appropriate facilities and support systems.