Stenting for Intracranial Atherosclerosis: Who, When,

and How

Alex Abou-Chebl, MD, FSVIN

Stroke Medical Director

Baptist Health Louisville

Disclosure Statement of Financial Interest

• Consulting Fees/Honoraria

• Consulting Fees/Honoraria

• Silk Road Medical

• Angiodynamics

Within the past 12 months, I or my spouse/partner have had a financial

interest/arrangement or affiliation with the organization(s) listed below.

Affiliation/Financial Relationship Company

Alex Abou-Chebl, MD

SAMMPRIS Criticisms

• 20 Cases Vetting Only 3 Wingspan, no need for

atherosclerosis experience

• General Anesthesia

• Cross lesion with microcatheter and exchange for balloon

• Initially no post-dilation allowed, protocol changed after

• SBP<150mmHg post-op SBP<120 reduced risk of ICH

with CAS

• No assessment of ASA/Plavix response

• Average 7days to

randomization

½ patients w ICH Tx 17days

after event- Low WASID risk

• No assessment of

cerebrovascular reserve

• No angiographic collateral

criteria

• Perforator strokes included

• Stenting vessels <2.5mm

• Lesion characteristics not

considered

Mori Classification

Alex Abou-Chebl, MD

Abou-Chebl A, Steinmetz H. Stroke 2012:43(2):616-620

Pathophysiology

• Thrombotic occlusion

Acute plaque rupture Thrombosis Vessel Occlusion Ischemia

• Artery-to-artery embolism

Acute plaque rupture/Turbulence/Sheer Stress Thrombosis Embolism Ischemia

• Hypoperfusion

Flow-limiting stenosis Autoregulation Failure Hypoperfusion Ischemia

• Branch Origin Occlusion- Perforator Syndromes

Atherosclerotic plaque buildup Encroachment/Occlusion ostia of perforators Ischemia

• Combination- Impaired “Washout of Emboli”

Alex Abou-Chebl, MD

Determinants of Risk & Severity of

Clinical Manifestations

• Stenosis Characteristics

• Collateral Blood Flow

Cerebrovascular Reserve

• Freq & Size of Embolism

• Severity of Hypoperfusion

• Duration of Ischemia

• Underlying Brain Substrate

Neuronal Reserve

• Age

• Medical Co-morbidities

Hyper/Hypoglycemia

• CRP & Fibrinogen predictors of recurrent CAD and stroke

• Bang OY teal. JNNP 2005

• Arenillas JF et al. Stroke.

2003;34:2463-2468.

% S

urv

ival fr

ee o

f IL

OD

-rela

ted

even

ts

Months after inclusion

Patients with CRP 1.41 mg/dlPatients with CRP > 1.41 mg/dl

P< .0001

Why Differentiating Hemodynamic

vs. Perforator Ischemia Matters

• Volume of Territory at Risk

• Eloquence of Tissue at Risk

• Maximizing Benefit from

Revascularization

• Reducing Risk of Revascularization

Alex Abou-Chebl, MD

Importance of CollateralsWASID Angiographic Dataset N=287 (of 569)

• “Across all stenoses extent of collaterals was a predictor for

subsequent stroke in the symptomatic arterial territory”

None vs. good HR 1.14, CI 0.39-3.30

Poor vs. good HR 4.36; 95% CI, 1.46-13.07; p < 0.0001

• 70-99% stenoses, more extensive collaterals risk of territorial stroke

None vs. good HR 4.60; 95% CI, 1.03-20.56

Poor vs. good HR 5.90; 95% CI, 1.25-27.81, p = 0.0427

• 50-69%, presence of collaterals associated with likelihood of stroke

None vs. good HR 0.18; 95% CI, 0.04-0.82

Poor vs. good HR 1.78; 95% CI, 0.37-8.57; p < 0.0001

• Multivariate analyses: extent of collaterals independent predictor for

subsequent stroke

None vs. good HR 1.62; 95% CI, 0.52-5.11

Poor vs. good, 4.78; 95% CI, 1.55-14.7; p = 0.0019

Alex Abou-Chebl, MD

Liebeskind D, et al. Ann Neurolo 2011;69:963-74

Decreased Flow Reserve in

Coronary Circulation

• Stenting of non-ischemic stenoses has no benefit

compared to Med Rx only

• Stenting of ischemia-related stenoses improves

Sx and outcome

• In multivessel CAD, identifying which stenoses

cause ischemia difficult:

Non-invasive tests often unreliable

Coronary angiography often results in under- or

overestimation of functional stenosis severity

Assessment of Cerebrovascular

Reserve

• Acetazolamide SPECT

Useful in combination with an anatomical study

Measures hemodynamic significance of stenosis

Identify pts. who may benefit from

revascularization

Annual Stoke Rates as high 25%• Eskey & Sanelli Neuroimag Clin N Am 2005;15

• Ozgur H, et al. AJNR 2001

Natural History of ICAD:

A Dynamic Process

• Wong et al. Stroke 2005;33:532-6.

Serial TCD study of 143 symptomatic MCA stenoses

• At 6 month TCD

– 29% Normalized 4.8% Recurrent Events

– 62% Stable 12.5% Recurrent Events

– 9% Progressed 38.5% Recurrent Events

– Total 10.5% Recurrent Events

• Arenillas et al. Stroke 2001;32:2898-2904

26.5month TCD study of 40 symptomatic MCA

• 32.5% Progressed

• 20% recurrent events

Predictor of Stroke

• Tandem stenosis in cervical ICA

• Lesion Progression

Alex Abou-Chebl, MD

Mori Classification

• Lesion based

• Length

• Eccentricity

• Predicts complications and reocclusion

• Type A: concentric, <5mm, smooth 8%

• Type B: eccentric, 5-10mm, angulated, irregular 26%

• Type C: >10mm, extreme angulation, total occl. 87%

Mori T, Kazita K, Chokyu K, Mima T, Mori K. Short-term arteriographic and clinical outcome after cerebral angioplasty and stenting for intracranial vertebrobasilar and carotid atherosclerotic occlusive disease. AJNR Am J Neuroradiol 2000 Feb;21:249-254.

Alex Abou-Chebl, MD

The Less Than Ideal ICAD Patient

42yo woman with coital headache and stroke

Alex Abou-Chebl, MD

Technical Result

Alex Abou-Chebl, MD

Indications

• >70% symptomatic stenosis

Focal, concentric, non-angulated, away from bifurcation

Distal territory Sx- no perforator Sx

• Failed medical Rx

Antiplatelet- dual

Statin

ACE-I

• Abnormal cerebrovascular reserve

Radiographic

Clinical• Pressure dependent

• Orthostatic Sx

• Progressive stenosis despite medical Rx

Alex Abou-Chebl, MD

Timing of Intervention

• Hyperperfusion syndrome can complicate CEA

and CAS ~1.1% with 0.6% risk of ICH

80% fatality rateAbou-Chebl A, et al. J Am Coll Cardiol 2004;43(9):1596-1601

• Small (N=18) series suggested high complication

rates ~50% w early intracranial interventionGupta R, et al. Neurology 2003;61:1729–1735

• Significant risk with delay in Tx- 56% recurrent

events in 28daysKozak O, et al. Neurosurgery 2011;69:334–343

• SAMMPRIS- risk of ICH independent of timing of

intervention relative to index eventFiorella D, et al. Stroke 2012;43:2682-2688

Approach

• Local anesthesia

Intraprocedural neurological assessments guide

therapeutic approach

• Primary stenting for vessels >2.5mm diameter

PTA for smaller vessels

Bailout stenting

• No wire exchanges or crossing with microcatheter

Cross with wire in balloon

• Slowly predilate all lesions

NTG

Size balloon 0.8:1

Never oversize or use stiff wires and balloons

Alex Abou-Chebl, MD

Intra-procedural Patient Monitoring

• 67% Developed Headache

Balloon Inflation 79.2%

Wire Positioning 62.5%

Stent Delivery 20.9%

Stent Deployment 16.7%

• 4.8% Developed Sx of Ischemia

2/3 Brainstem Hypoperfusion during PTA

• Decrease Inflation Duration

1/3 Hemispheric after Completion of Intervention

• Repeat Angiogram Stent Thrombosis

• GPIIb/IIIa Inhibitor

• Successful Recanalization Recovery

Abou-Chebl A, et al. J Neuroimaging 2006;16(3): 216-223

Alex Abou-Chebl, MD

Clopidogrel Response and Risk of Peri-

procedural Thrombotic Complications with

Cerebrovascular Interventions• Unpublished data

N=71 (2000-2002)

Optical Platelet Aggregometry• ADP and Arachidonic Acid

Total

Patients without

Thrombotic

Complication

Patients with

Thrombotic

ComplicationEndovascular

60 53 7ADP %-

aggregation (mean±SD)

33±16.3% 31±14.8% 54.6±16.2% p=0.008

AA %-aggregation 22.6±10.2 22.3±10.3% 26±8.7% p=0.32

ADP- adenosine diphosphate, SD- standard deviation, AA- arachidonic acid

Smout J, Macdonald S, Stansby G International Journal of Stroke. Vol5, Dec 2010; 477-482

Gray et al: JACC Interv 2011

Importance of Experience

Alex Abou-Chebl, MD

U.S.-China Multicenter Balloon Expandable vs.

Self-Expanding Stent Registry

• 670 lesions treated in 637 patients

• Mean age 57±13 years

• Location of stent placement:

MCA 270 (40%)

Posterior circulation 263 (39%)

Intracranial ICA 137 (21%).

• Stent type:

BMS 68%, DES 5%, SES 32%

Technical failure rate: BMS 7.1% and SES 1.4%, (p<0.001)

Jiang W, Cheng-Ching E, Abou-Chebl A , et al. Neurosurgery 2011

Alex Abou-Chebl, MD

Results

• 30 day peri-procedural stroke or death 6.1%

• Deaths 0.94%

• Independent Predictors of Stroke or Death

Variable OR 95% CI p

Treatment < 24 hrs 4.0 1.6 -6.7 < 0.001

Mori Type A 0.31 0.13 – 0.72 0.007

Alex Abou-Chebl, MD

Summary

• Intracranial Atherosclerosis is Common

• With Med Tx Recurrence Rates are ~12-22%/yr

Aspirin+clopidogrel+atorva/rosuvastatin is “Best” Medical Therapy• No role for Warfarin

• PTA/Stenting safe and effective in selected symptomatic patients

Most effective in patients with decreased cerebrovascular reserve

• Treatment should not be delayed in non-disabled patients

• Operator experience and appropriate technique are critical for success

Alex Abou-Chebl, MD