What is the preferred technique for stenting intracranial atherosclerotic disease?

Preferred Technique for Stenting Intracranial Atherosclerotic Disease

The preferred technique for stenting intracranial atherosclerotic disease is balloon angioplasty followed by placement of a self-expanding stent, specifically the Wingspan stent system with Gateway PTA Balloon Catheter. 1

Technical Approach

Pre-procedural Considerations

• Patient selection criteria:
  • Symptomatic intracranial stenosis ≥50% that is refractory to medical therapy
  • Failure of aggressive medical management including antiplatelet therapy, statins, and blood pressure control

Procedural Technique

1. Initial balloon angioplasty:

   • Submaximal balloon dilatation (undersizing the balloon)
   • Target: Reduction of stenosis to approximately 50% (average achieved is 43.5±18.1%) 2
   • This step minimizes the risk of vessel dissection and rupture

2. Self-expanding stent deployment:

   • Placement of self-expanding nitinol microstent (Wingspan) across the atherosclerotic lesion
   • Advantage: Slow stent expansion over several weeks, minimizing risk of vessel dissection and rupture 1
   • Target: Further reduction of stenosis to approximately 30% (average achieved is 27.2±16.7%) 2

3. Technical success definition:

   • Reduction of stenosis grade to ≤50% 1
   • Successful stent placement across the target lesion

Device Selection

The Wingspan Stent System with Gateway PTA Balloon Catheter is specifically designed for intracranial applications and received FDA humanitarian device exemption approval in 2005 1. This system offers several advantages:

• Self-expanding design allows for gradual vessel expansion
• Minimizes risk of vessel dissection and rupture compared to balloon-mounted stents
• High technical success rate (98.8%) 2
• Designed specifically for the unique challenges of intracranial vasculature

Post-procedural Management

Antiplatelet Therapy

• Dual antiplatelet therapy with aspirin (325 mg daily) and clopidogrel (75 mg daily) for a minimum of 4 weeks after the procedure 1
• Followed by aspirin therapy (325 mg daily) indefinitely 1

Monitoring

• Regular assessment for restenosis, particularly in anterior circulation where ISR rates are higher (42% vs 13% in posterior circulation) 3
• Follow-up imaging at 3-6 months to evaluate for in-stent restenosis

Important Considerations and Pitfalls

Anatomical Considerations

• Anterior circulation has higher rates of in-stent restenosis (42%) compared to posterior circulation (13%) 3
• Lengthy lesions requiring more than one stent have higher risk of thrombosis 3

Potential Complications

1. In-stent restenosis:

   • Occurs in approximately 30% of cases 3
   • More common in anterior circulation
   • May require target vessel revascularization

2. Periprocedural complications:

   • Stroke or death rate of approximately 4.5-6.1% within 30 days 2
   • Vessel dissection, perforation, or thrombosis
   • Side branch occlusion

Limitations and Contraindications

• Highly tortuous vessels may limit stent delivery
• Extremely calcified lesions may respond poorly to angioplasty
• Avoid in patients who cannot tolerate dual antiplatelet therapy

Future Directions

While the Wingspan stent system represents the current preferred technique, ongoing research continues to evaluate newer devices and approaches. The high rate of in-stent restenosis (approximately 30%) remains a concern that warrants continued refinement of techniques and devices 3, 4.

Endovascular intervention should only be performed at high-volume centers with significant neurovascular expertise, as outcomes are highly operator-dependent 5.