What is the recommended endovascular treatment for intracranial artery dissection?

Endovascular Treatment for Intracranial Artery Dissection

Endovascular stent placement is a viable treatment option for symptomatic intracranial artery dissection, particularly when medical management fails or when there is ongoing ischemia, but it should be reserved for carefully selected cases given the lack of high-quality evidence and the availability of effective medical therapy. 1

Primary Treatment Approach

Medical management with antithrombotic therapy is the first-line treatment for intracranial artery dissection. 1 However, unlike extracranial dissections where either antiplatelet or anticoagulation therapy is considered reasonable, there is a critical lack of evidence specifically regarding anticoagulation use in intracranial arterial dissection, and treatment decisions must be based on individual clinical factors. 1

Key Differences from Extracranial Dissection

• For extracranial carotid or vertebral dissection, either antiplatelet therapy or anticoagulation with heparin/warfarin is considered reasonable with no clear superiority of one over the other. 1
• For intracranial dissection specifically, the guidelines explicitly state there is insufficient evidence to guide anticoagulation use, requiring individualized decision-making based on clinical presentation (ischemic vs. hemorrhagic). 1

Indications for Endovascular Intervention

Endovascular stent placement should be considered when:

• The patient presents with symptomatic dissection causing ongoing ischemia despite medical therapy. 2, 3
• There is documented failure of adequate medical management with recurrent ischemic events. 4, 5
• The dissection is associated with significant stenosis or pseudoaneurysm formation threatening parent artery patency. 2

Technical Considerations

• Self-expanding stents (such as the Wingspan system) are preferred for intracranial applications because they allow slow stent expansion over several weeks, minimizing the risk of vessel dissection and rupture. 1
• The goal is to exclude the dissection/pseudoaneurysm from circulation while preserving the parent artery. 2
• Technical success rates for stent placement in intracranial dissections are approximately 90%, with optimal positioning achieved in 77.8% of cases. 2

Timing of Intervention

Avoid early endovascular intervention within 7 days of acute stroke, as patients treated in the acute phase have significantly higher procedure-related complications. 4 The procedure should ideally be performed at least 7 days after the ischemic event when the patient is clinically stable. 4

Antiplatelet Management

Dual antiplatelet therapy is mandatory before and after stent placement:

• Loading with aspirin (160-325 mg) and clopidogrel (300-600 mg loading dose) prior to the procedure. 1, 4
• Continue dual antiplatelet therapy (aspirin 75-325 mg daily plus clopidogrel 75 mg daily) for a minimum of 4 weeks post-procedure. 1
• For bare-metal stents, continue dual therapy for at least 1 month, ideally up to 12 months. 6
• After the dual therapy period, continue single antiplatelet therapy (aspirin or clopidogrel) indefinitely. 4, 5

Critical Caveat on Bleeding Risk

The MATCH trial demonstrated that dual antiplatelet therapy increases major hemorrhage risk by 1.3% absolute increase in life-threatening bleeding compared to single agent therapy. 1 This risk must be carefully weighed, particularly in patients with intracranial dissection who may already have hemorrhagic complications.

Institutional Requirements

Endovascular procedures for intracranial dissection should only be performed at:

• High-volume academic medical centers with significant neurovascular expertise. 4, 5
• Centers with experienced multidisciplinary teams including vascular neurologists, neuroendovascular specialists, neuroanesthesiologists, and neurointensivists. 4
• Institutions that routinely audit their performance results and perioperative complication rates. 1

Expected Outcomes and Complications

Short-term outcomes:

• No instances of postprocedural ischemic attacks or new neurological deficits were reported in one case series of 10 patients with intracranial dissection treated with stents. 2
• Parent artery preservation was achieved in all successfully treated patients. 2
• All patients showed functional improvement or stable clinical status on modified Rankin scale at follow-up. 2

Potential complications include:

• Arterial perforation leading to intracerebral or subarachnoid hemorrhage. 1
• Acute arterial occlusion from mechanical dissection, thrombus formation, or severe vasospasm. 1
• In-stent thrombosis if dual antiplatelet therapy is discontinued prematurely. 6

Follow-up and Surveillance

Angiographic follow-up should be performed:

• Initially at 3 months post-procedure to assess for restenosis. 1
• At 6 and 12 months after endovascular revascularization. 1
• In yearly intervals thereafter as clinically indicated. 1
• Immediately if new symptoms develop. 1

The restenosis rate after stent placement for intracranial dissection is approximately 11-14%, which is lower than angioplasty alone. 7 MRI with MRA can be used for noninvasive surveillance, though catheter-based angiography remains the gold standard for accurately establishing the grade of restenosis. 1

Common Pitfalls to Avoid

• Do not proceed with endovascular intervention without first attempting medical management, as most intracranial dissections can be managed conservatively with antithrombotic therapy. 1, 8
• Do not perform procedures at low-volume centers or by inexperienced operators, as outcomes are highly operator and institution-dependent. 4
• Do not discontinue dual antiplatelet therapy prematurely, as this is one of the most significant risk factors for stent thrombosis. 6
• Do not use anticoagulation indiscriminately in intracranial dissection, particularly if there is any hemorrhagic component (subarachnoid hemorrhage), as the risk-benefit ratio is unclear. 1, 8

Alternative Considerations

For intracranial dissections presenting with subarachnoid hemorrhage rather than ischemia, surgical or endovascular treatment to prevent rebleeding may be necessary, and the treatment approach differs significantly from ischemic presentations. 8 In cases where the dissection leads to pseudoaneurysm enlargement despite stent placement, proximal occlusion using coils may be required as a salvage procedure. 2