Carlos E. Baccin, MD; James D. Rabinov, MD

KEY FACTS

Terminology
Pre-Procedure
Procedure
Post-Procedure
Outcomes

TERMINOLOGY

Intracranial Stenosis Due to Atherosclerosis
- Causes 8-10% of ischemic strokes in North America
- Risk factors for intracranial stenosis
  - Hypertension
  - Race
    - Asian
      - Most common cause of stroke (33-56%)
    - Latino
    - African descent
  - Metabolic syndrome
- Mechanisms of ischemic stroke due to intracranial stenosis
  - Thromboembolism distal to stenosis
  - In situ thrombosis at arterial stenosis
  - Hemodynamic hypoperfusion distal to stenosis
  - Perforating/branch artery occlusion by atheroma
- Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study
  - Patients with prior TIA/nondisabling stroke from symptomatic intracranial stenosis of 50-99% severity
    - Randomized to warfarin or aspirin
      - Aspirin shown to be safer and as effective
    - 15% stroke rate in stenotic territory over 1.8 years
      - 44% of these strokes disabling
      - If stenosis ≥ 70%, stroke rate was 23%
Intracranial Stenosis Angioplasty/Stenting
- Primary angioplasty (PTA) of symptomatic intracranial stenoseswithout stenting
  - Early studies reported high PTA-associated risks
    - Vessel rupture, vasospasm, dissection
    - Death in up to 33% of patients
  - Subsequently, several reports of successful PTA
    - Slower balloon inflation and balloon undersizing
      - Reduced complications
      - Occasionally suboptimal angiographic results
  - Cochrane review of 79 articles (total of 1,999 cases)
    - Included case series with ≥ 3 cases of 1° PTA
      - Overall perioperative stroke rate (7.9%)
      - Perioperative death rate (3.4%)
      - Perioperative stroke or death rate (9.5%)
      - 1-year follow-up stroke rate (6%)
  - Technical disadvantages as opposed to stenting
    - Arterial dissection
      - Potential for increased thrombogenicity
    - Immediate elastic recoil
    - Higher re-stenosis rates
  - No trials comparing PTA vs. stenting
- Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries (SSYLVIA trial)
  - Trial using Neurolink® (Guidant; San Francisco, CA) balloon expandable stent
    - Successful stent placement (95%)
    - 30-day periprocedural stroke rate (6.6%)
    - 6 months after stenting > 50% re-stenosis in 32% of intracranial stents
      - 61% of recurrent stenoses were asymptomatic
    - Neurolink stent no longer manufactured
- Wingspan study: Prospective multicenter trial
  - Successful stent placement (97.8%)
    - Self-expanding nitinol stent deployed after PTA
  - 30-day periprocedural stroke/death rate (4.5%)
  - At 6-month angiographic follow-up
    - > 50% restenosis in 6.8%; all symptomatic
  - At 6-month clinical follow-up
    - Ipsilateral stroke/death rate (7.0%)
    - All strokes (9.7%)
    - All-cause mortality (2.3%)
  - FDA granted humanitarian device exemption (HDE)
    - Based upon results of Wingspan study
  - NIH Multicenter Wingspan Stent Registry
    - 129 patients with 70–99% intracranial stenosis
      - Stenosis reduced to < 50% in 97% of patients
      - 30-day stroke or death risk (9.6%)
- Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS trial)
  - Compares safety/effectiveness of intensive medical therapy plus stenting vs. intensive medical therapy alone for intracranial stenosis
    - Entry criteria
      - Symptomatic intracranial stenosis ≥70%
      - TIA or stroke within 30 days
    - Both study arms receive dual antiplatelet therapy
      - Aspirin, clopidogrel for 3 months after enrolling
    - Intensive management of vascular risk factors
      - Blood pressure/cholesterol management
    - Enrollment stopped prematurely
      - Better outcomes with medical than stent group
      - 30-day death/stroke rate: PTA/stenting (14%) vs. medical therapy (5.8%)
      - Trial will continue to follow enrolled subjects

PRE-PROCEDURE

Indications
Contraindications
Pre-Procedure Imaging
Getting Started

PROCEDURE

Equipment Preparation
Procedure Steps
Findings and Reporting
Alternative Procedures/Therapies

POST-PROCEDURE

Expected Outcome
Things to Do

OUTCOMES

Complications

Selected References

Al-Ali F et al: Predictors of unfavorable outcome in intracranial angioplasty and stenting in a single-center comparison: results from the borgess medical center-intracranial revascularization registry. AJNR Am J Neuroradiol. 32(7):1221-6, 2011
Li J et al: Wingspan stent for high-grade symptomatic vertebrobasilar artery atherosclerotic stenosis. Cardiovasc Intervent Radiol. Epub ahead of print, 2011
Short JL et al: Endovascular treatment of symptomatic intracranial atherosclerotic disease. Front Neurol. 1:160, 2011
Yu SC et al: Angioplasty and stenting of atherosclerotic middle cerebral arteries with wingspan: evaluation of clinical outcome, restenosis, and procedure outcome. AJNR Am J Neuroradiol. 32(4):753-8, 2011
Fields JD et al: Indications and applications of arterial stents for stroke prevention in atherosclerotic intracranial stenosis. Curr Cardiol Rep. 12(1):20-8, 2010
Lutsep HL: Symptomatic intracranial stenosis: best medical treatment vs. intracranial stenting. Curr Opin Neurol. 22(1):69-74, 2009
Schumacher HC et al: Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis. J Vasc Interv Radiol. 20(7 Suppl):S451-73, 2009
Bose A et al: A novel, self-expanding, nitinol stent in medically refractory intracranial atherosclerotic stenoses: the Wingspan study. Stroke. 38(5):1531-7, 2007
Cruz-Flores S et al: Angioplasty for intracranial artery stenosis. Cochrane Database Syst Rev. 3:CD004133, 2006
Marks MP et al: Angioplasty for symptomatic intracranial stenosis: clinical outcome. Stroke. 37(4):1016-20, 2006
Mazighi M et al: Prospective study of symptomatic atherothrombotic intracranial stenoses: the GESICA study. Neurology. 66(8):1187-91, 2006
SSYLVIA Study Investigators: Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries (SSYLVIA): study results. Stroke. 35(6):1388-92, 2004
Connors JJ 3rd et al: Percutaneous transluminal angioplasty for intracranial atherosclerotic lesions: evolution of technique and short-term results. J Neurosurg. 91(3):415-23, 1999

Related Anatomy

Related Differential Diagnoses

References

Tables

KEY FACTS

Terminology
Pre-Procedure
Procedure
Post-Procedure
Outcomes

TERMINOLOGY

Intracranial Stenosis Due to Atherosclerosis
- Causes 8-10% of ischemic strokes in North America
- Risk factors for intracranial stenosis
  - Hypertension
  - Race
    - Asian
      - Most common cause of stroke (33-56%)
    - Latino
    - African descent
  - Metabolic syndrome
- Mechanisms of ischemic stroke due to intracranial stenosis
  - Thromboembolism distal to stenosis
  - In situ thrombosis at arterial stenosis
  - Hemodynamic hypoperfusion distal to stenosis
  - Perforating/branch artery occlusion by atheroma
- Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study
  - Patients with prior TIA/nondisabling stroke from symptomatic intracranial stenosis of 50-99% severity
    - Randomized to warfarin or aspirin
      - Aspirin shown to be safer and as effective
    - 15% stroke rate in stenotic territory over 1.8 years
      - 44% of these strokes disabling
      - If stenosis ≥ 70%, stroke rate was 23%
Intracranial Stenosis Angioplasty/Stenting
- Primary angioplasty (PTA) of symptomatic intracranial stenoseswithout stenting
  - Early studies reported high PTA-associated risks
    - Vessel rupture, vasospasm, dissection
    - Death in up to 33% of patients
  - Subsequently, several reports of successful PTA
    - Slower balloon inflation and balloon undersizing
      - Reduced complications
      - Occasionally suboptimal angiographic results
  - Cochrane review of 79 articles (total of 1,999 cases)
    - Included case series with ≥ 3 cases of 1° PTA
      - Overall perioperative stroke rate (7.9%)
      - Perioperative death rate (3.4%)
      - Perioperative stroke or death rate (9.5%)
      - 1-year follow-up stroke rate (6%)
  - Technical disadvantages as opposed to stenting
    - Arterial dissection
      - Potential for increased thrombogenicity
    - Immediate elastic recoil
    - Higher re-stenosis rates
  - No trials comparing PTA vs. stenting
- Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries (SSYLVIA trial)
  - Trial using Neurolink® (Guidant; San Francisco, CA) balloon expandable stent
    - Successful stent placement (95%)
    - 30-day periprocedural stroke rate (6.6%)
    - 6 months after stenting > 50% re-stenosis in 32% of intracranial stents
      - 61% of recurrent stenoses were asymptomatic
    - Neurolink stent no longer manufactured
- Wingspan study: Prospective multicenter trial
  - Successful stent placement (97.8%)
    - Self-expanding nitinol stent deployed after PTA
  - 30-day periprocedural stroke/death rate (4.5%)
  - At 6-month angiographic follow-up
    - > 50% restenosis in 6.8%; all symptomatic
  - At 6-month clinical follow-up
    - Ipsilateral stroke/death rate (7.0%)
    - All strokes (9.7%)
    - All-cause mortality (2.3%)
  - FDA granted humanitarian device exemption (HDE)
    - Based upon results of Wingspan study
  - NIH Multicenter Wingspan Stent Registry
    - 129 patients with 70–99% intracranial stenosis
      - Stenosis reduced to < 50% in 97% of patients
      - 30-day stroke or death risk (9.6%)
- Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS trial)
  - Compares safety/effectiveness of intensive medical therapy plus stenting vs. intensive medical therapy alone for intracranial stenosis
    - Entry criteria
      - Symptomatic intracranial stenosis ≥70%
      - TIA or stroke within 30 days
    - Both study arms receive dual antiplatelet therapy
      - Aspirin, clopidogrel for 3 months after enrolling
    - Intensive management of vascular risk factors
      - Blood pressure/cholesterol management
    - Enrollment stopped prematurely
      - Better outcomes with medical than stent group
      - 30-day death/stroke rate: PTA/stenting (14%) vs. medical therapy (5.8%)
      - Trial will continue to follow enrolled subjects

PRE-PROCEDURE

Indications
Contraindications
Pre-Procedure Imaging
Getting Started

PROCEDURE

Equipment Preparation
Procedure Steps
Findings and Reporting
Alternative Procedures/Therapies

POST-PROCEDURE

Expected Outcome
Things to Do

OUTCOMES

Complications

Selected References

Al-Ali F et al: Predictors of unfavorable outcome in intracranial angioplasty and stenting in a single-center comparison: results from the borgess medical center-intracranial revascularization registry. AJNR Am J Neuroradiol. 32(7):1221-6, 2011
Li J et al: Wingspan stent for high-grade symptomatic vertebrobasilar artery atherosclerotic stenosis. Cardiovasc Intervent Radiol. Epub ahead of print, 2011
Short JL et al: Endovascular treatment of symptomatic intracranial atherosclerotic disease. Front Neurol. 1:160, 2011
Yu SC et al: Angioplasty and stenting of atherosclerotic middle cerebral arteries with wingspan: evaluation of clinical outcome, restenosis, and procedure outcome. AJNR Am J Neuroradiol. 32(4):753-8, 2011
Fields JD et al: Indications and applications of arterial stents for stroke prevention in atherosclerotic intracranial stenosis. Curr Cardiol Rep. 12(1):20-8, 2010
Lutsep HL: Symptomatic intracranial stenosis: best medical treatment vs. intracranial stenting. Curr Opin Neurol. 22(1):69-74, 2009
Schumacher HC et al: Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis. J Vasc Interv Radiol. 20(7 Suppl):S451-73, 2009
Bose A et al: A novel, self-expanding, nitinol stent in medically refractory intracranial atherosclerotic stenoses: the Wingspan study. Stroke. 38(5):1531-7, 2007
Cruz-Flores S et al: Angioplasty for intracranial artery stenosis. Cochrane Database Syst Rev. 3:CD004133, 2006
Marks MP et al: Angioplasty for symptomatic intracranial stenosis: clinical outcome. Stroke. 37(4):1016-20, 2006
Mazighi M et al: Prospective study of symptomatic atherothrombotic intracranial stenoses: the GESICA study. Neurology. 66(8):1187-91, 2006
SSYLVIA Study Investigators: Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries (SSYLVIA): study results. Stroke. 35(6):1388-92, 2004
Connors JJ 3rd et al: Percutaneous transluminal angioplasty for intracranial atherosclerotic lesions: evolution of technique and short-term results. J Neurosurg. 91(3):415-23, 1999

KEY FACTS

Terminology

Pre-Procedure

Procedure

Post-Procedure

Outcomes

TERMINOLOGY

Intracranial Stenosis Due to Atherosclerosis

Intracranial Stenosis Angioplasty/Stenting

PRE-PROCEDURE

Indications

Contraindications

Pre-Procedure Imaging

Getting Started

PROCEDURE

Equipment Preparation

Procedure Steps

Findings and Reporting

Alternative Procedures/Therapies

POST-PROCEDURE

Expected Outcome

Things to Do

OUTCOMES

Complications

Selected References

Tables

KEY FACTS

Terminology

Pre-Procedure

Procedure

Post-Procedure

Outcomes

TERMINOLOGY

Intracranial Stenosis Due to Atherosclerosis

Intracranial Stenosis Angioplasty/Stenting

PRE-PROCEDURE

Indications

Contraindications

Pre-Procedure Imaging

Getting Started

PROCEDURE

Equipment Preparation

Procedure Steps

Findings and Reporting

Alternative Procedures/Therapies

POST-PROCEDURE

Expected Outcome

Things to Do

OUTCOMES

Complications

Selected References