stenting for intracranial atherosclerosis: who, when, and how...stenting for intracranial...
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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