carotid artery stenting where do we stand in 2013?
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Carotid Artery Stenting Where do we stand in 2013?. Chong Tze Tec MBBS FACS Consultant Vascular and Endovascular Surgeon Singapore General Hospital Adjunct Assistant Professor of Surgery Duke NUS Medical School. Stroke. 3 rd leading cause of death in US - PowerPoint PPT PresentationTRANSCRIPT
Carotid Artery StentingWhere do we stand in 2013?
Chong Tze Tec MBBS FACSConsultant Vascular and Endovascular Surgeon
Singapore General HospitalAdjunct Assistant Professor of Surgery
Duke NUS Medical School
Stroke
• 3rd leading cause of death in US
• 750 000 people will have a stroke this year
• 160 000 will die from it
• 15-30% become permanently disabled
• 20-30% caused by extracranial carotid disease
• Carotid endarterectomy
• Carotid artery stenting
• Unresolved issues
Carotid Endarterectomy Procedures
CEA: Large-Scale Randomized Trials
• ECST (1991)
• NASCET (1991)
• VA Asymptomatic Study (1993)
• ACAS (1995)
• ACST (2004)
Barnett HJM et al NEJM 1998;339:1415-1425
26% vs 9% rate at 2 years
NASCET
ACAS Investigators JAMA 1995;273:1421
11% vs 5.1% rate at 5 years; p=.004
ACAS
Curves cross at 3 years
Curves cross at 1.5 years
ACST
Results
Carotid Artery Stenting
Carotid Stenting- Indications
• Carotid restenosis• Anatomically difficult lesion (e.g. above C2)• Radiation-induced disease• “High-risk” patients
- Consensus Conference, Montefiore Vascular Symposium 2001
“High Risk” criteria for CEA ?Anatomic/technical
• Inaccessible
lesion
• Hostile neck
• Radiation
disease
• Restenotic
lesion
Comorbidities
• Age>80
• CHF
• Recent coronary
event or procedure
• COPD
• Contralateral
occlusion
• Renal failure
CEA vs CAS: Major RCTs
• CAVATAS (Lancet 2001)• SAPPHIRE (NEJM 2004)• SPACE (Lancet 2006)• EVA-3S (NEJM 2006)• CREST (2010)• ICSS (2009)
SAPPHIRE
SAPPHIRE Primary endpoints
1. Death/stroke/MI within 30 days2. Death/ipsilateral stroke between 31 days
and 1 year
747 patients were enrolled in the study and 334 patients underwent randomization. Of those not randomized, 406 entered into a stent registry and 7 entered a surgical registry
SAPPHIRE results
SAPPHIRE Discussion
• CAS is not inferior to CEA in high risk patients based on 1 year data
• Trial was terminated early due to the establishment of nonrandomized stent registries
SPACEStent-Supported Percutaneous Angioplasty of the Carotid
Artery versus Endarterectomy
SPACE Hypothesis
• CAS is not inferior to CEA for the treatment of severe symptomatic carotid stenosis
SPACE results
SPACE Discussion
• SPACE failed to prove the non-inferiority of CAS compared to CEA
• 30d stroke/death rate was 6.84% for CAS versus 6.34% for CEA
• CEA 30d event rates are similar to NASCET (6.5%)
SPACE – Follow up
SPACE – Follow up results
SPACE – Follow up results
• Recurrent restenosis >70% was higher in the CAS group compared to the CEA group at 2 years– 10.7% vs 4.6%, p=0.0009
EVA-3S
EVA-3S: Results at 30 days
EVA-3S – Follow up
EVA-3S – Follow up results
• Cumulative probability of periprocedural stroke or death and non-procedural ipsilateral stroke at 4 years
CAS vs CEA trials
• Failed to show benefit so far
• Perhaps there are subtleties involved which are underappreciated
– Lesion characteristics
– Technical aspects to CAS
– Operator experience
Confounding issues
• Arch anatomy• Stents design• Embolic protection devices• Plaque evaluation
Open cell vs Closed cell stents
Open cell stents are more conformable therefore offer better wall apposition and are more flexible and trackable
Cerebral embolization, as detected by TCD and DW-MRI, occurs with similar frequency After CAS with open-cell and closed-cell stents… does not support the superiority of any stent design with respect to cerebral embolization
Cerebral Protection Devices
Difficult Anatomies for Distal Protection
MOMA device
Gore Flow Reversal System
Embolic protection
• Asymptomatic lesions (n=36)• Diffusion weighted MRI at 24h post
procedure• Average number of hits 6.1 vs 6.2 • Filter group did not show reduction in
microemboli
?
Transcranial Doppler (TCD)
• Allow precise assessment of number embolic (air, contrast, particles) events during procedure.
Procedure CEA CAS
Number of hits
52±64 202±119
Crawley F, Clifton A, Buckenham T, et al. Comparison of hemodynamic cerebral ischemia and microembolic signals detected during CEA and CAS. Stroke 1997
ICSS MRI study
Compared to patients undergoing CEA, patients treated with CAS had higher numbers of periprocedural ischemic brain lesions, and lesions were smaller and more likely to occur in cortical areas and subajacent white matter. These findings may reflect differences in underlying mechanisms of cerebral ischemia
Cerebral embolizationAre EPDs needed ?
J Vasc Surg 2012;56:1579-84.
Plaque evaluation – GSM (Gray Scale Median)
Carotid plaque echolucency increases the risk of stroke? (GSM <25)
GSM
CREST trial
•
Long term follow up?
No difference
Cochrane Review 2012
• Endovascular treatment is associated with an increased risk of peri-procedural stroke or death compared with endarterectomy. However, this excess risk appears to be limited to older patients… Further trials are needed to determine the optimal treatment for asymptomatic carotid stenosis
Guidelines ?
… the disagreement in the five most recent guidelines, and the likelihood of ongoing and future improvements in CAS make it possible that the 2011 carotid guidelines may turn out to be misleading or incorrect…
Advances in CEA
Perioperative stroke and death rate - Symptomatic
Perioperative stroke and death rate - Asymptomatic
CAS is also evolving
Why do we treat carotid disease?
• To prevent strokes
Options for treatment
• Carotid endarterectomy
• Carotid artery stenting
• Medical management
The End