Transcript The Future of Endovascular Neurosurgery

Carotid Stenting:
Unanswered Questions and
Future Directions
Rod Samuelson, Elad Levy, LN Hopkins
University at Buffalo Neurosurgery
October 2006
LN Hopkins, MD
Potential Conflicts
Consultant & research support:
Boston Scientific, Cordis, Medtronic,
Guidant
Financial interests:
Boston Scientific EPI, Cordis, J&J,
Micrus, Endotex, Access Closure Inc
Carotid Stenosis
What do We Know?
In LOW RISK Patients:
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CEA is of benefit (greater for Sx pts)
CEA of more benefit with severe stenosis
CEA of more benefit in elderly
CEA must be done safely
Carotid Stenosis
What do We Know?
In Asymptomatic Low Risk Patients
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CEA is better than medical therepy
CEA prevents strokes in women (ACST)
CEA prevents disabling strokes (ACST)
CEA prevents fatal strokes (ACST)
Carotid Stenosis
What do We Know?
In Elderly Patients:
• Stroke risk is much higher in elderly pts
• CEA greatly benefits elderly low risk pts
• CEA risk is increased in elderly patients
Carotid Stenosis
What do We Know?
• Definition of High Risk for CEA
• CAS risk = CEA in High Risk pts
• CAS & CEA risk is higher in elderly pts
and in symptomatic pts
Unanswered Questions
• Should we treat Symptomatic low risk pts
with CAS or CEA?
• Embolic protection no/ yes/ what type?
• Which is better: Open or Closed cell stents
• What training is best for CAS
Unanswered Questions
• What is High Risk for CAS ?
• Should we treat elderly pts with CAS ?
• Are high risk (CEA) pts at higher risk for
stroke ??
• The “3% Rule” ????
A Few Helpful Facts…
Asymptomatic Carotid Stenosis and
Risk of Stroke Study (ACSRS)
Asymptomatic Patients with Medical
CoMorbidities And Severe Stenosis…
Stroke rate up to 6% per year !!
The “3 % Rule” does not apply to High Risk pts
Kakkos,Nicolaides et al
Int Angiol ’05, 24, 221-30
Elderly Patients(75-79)
NASCET Analysis
• Absolute risk reduction(ARR) overall = 17%
• ARR in pts 75-79 = 30%
Some Stroke Facts…
• Only 1/3 of strokes are preceded by TIA
Caplan et al
• Many TIA’s are never diagnosed
Castaldo, Tool et al, Arch neurol, 1997
• Many Stroke are never diagnosed
Stroke Facts…
• Silent infarcts (CT&MRI) noted in
12-70% of asx pts
(ACST) Halliday
• Silent infarcts seen in 15% of
ACAS patients
Other “Non Symptom” Symptoms
• Neurocognitive function impaired in
asymptomatic patients.
Raabe, SIR March ’06
• Dizzyness ???
High Risk CAS
• Not the same as for CEA
• Are CEA and CAS complementary ?
• What are identified CAS risk factors?
• How to make CAS SAFER ?
Current CAS Results (D/S/MI)
High Risk Registries
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CAPTURE
CREATE
BEACH
CABERNET
CASES
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Current CAS Results
Outliers, But RPCT
• SPACE
• EVA 3S
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10
CAPTURE STROKE COHORT:
Summary- Capture 3500 patients
• Overall stroke rate = 4.8%
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Major stroke rate = 2.0%
Minor stroke rate = 2.9%
Ipsilateral stroke rate= 4.0%
Non-ipsilateral stroke rate= 0.9%
(18% of all strokes)
CAPTURE STROKE COHORT:
Summary of Strokes
• Stroke rate in high risk population is 4.8%
• Major stroke rate = 2.0%
• Non-ipsilateral represents 18% of strokes of a cumulative
0.9% rate
• No non-ipsilateral strokes reported during the procedure
• 38% of strokes occurred after 24 hours
• 78% of strokes occurred post-procedure and postdischarge
CAPTURE
Gender & Symptoms
• DSMI overall Sx pts 12.2
• DS (F Worse) Sx F <80 vs
Asx 5.3 (.0001)
Sx M <80 (.03)
CAPTURE Post Market Registry
3000 pts
FDA Selection Criteria
Octogenarians
• Age > 80
713/3000 pts(24%)
• Independent predictors DSMI @ 30 days…
• DSMI = 9.4(>80) vs 5.2(<80)
• Calcification (mod+)
• Predilitation for filter
stroke alone
• Multiple stents
>80 stroke alone
OR 1.39
OR 3.22
OR 4.02
OR 1.77
OR3.14
CAPTURE STROKE COHORT:
Questions
• Why do many strokes occur after the procedure (78%) or after 24
hours (38%)? Would Closed Cell stents be better??
• Why do 18 % occur in a vessel that has not been manipulated?
• Does the answer lie in?
– Arch Type, calcification and overall plaque morphology
– Improved technical equipment
– Medical therapy before and after the procedure
CREATE High Risk Registry
EV3 Stent + Spider Filter
30 Day Results
• 30 day death, stroke and MI
• Major Stroke
• Hemorrhage
• Risk Factors
Symptomatic carotid stenosis
Renal failure
Duration of filter deployment
6.2%
3.5%
1.3%
SPACE Trial
RPCT
N=1200
Death, Stroke and MI - 30 day
CAS
6.8%
CEA
6.3%
p = 0.09
CEA better in older patients
CAS Risk Factors
1)Symptomatic lesion
2)Sx > age 80
3)Renal Failure
4)Multiple stents
5)Duration Filter deployment
6)Pre dilitation
7)Tortuous/calcified arteries
CAS
Non Predictors of Risk
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Sex ?? CAPTURE
Calcification
Residual stenosis
Filter
Contralateral occlusion
Smoking
Diabetes
Statins
Newer Results
What Do They Mean?
• Endarterectomy versus Stenting in
Patients with Symptomatic Severe Carotid
Stenosis
• EVA-3S Trial
• New England Journal of Medicine
• October 19, 2006
EVA-3S Trial: Results
• 30 Day rate of any stroke or death
– Endarterectomy = 3.9%
– Carotid Stent = 9.6%
– Relative Risk of 2.5 (95% CI 1.2 to 5.1)
• 30 Day rate of disabling stroke or death
– Endarterectomy = 1.5%
– Carotid Stent = 3.4%
– Relative Risk of 2.2 (95% CI 0.7 to 7.2)***
– Not statistically significant
EVA-3S Trial: Limitations
• Distal protection was only “[strongly]
recommended” after February 2003 (50%
trial duration)
– 30 day stroke or death
– Without DEP = 25% (5 of 20)
– With DEP = 7.9% (18 of 227)
• If 7.9% rather than 9.6% is used:
– Relative Risk = 2.0 (p = 0.07)
EVA-3S Trial: Limitations
• Rates of MI were not assessed
– (Reduced rate of MI was one source of
benefit identified in the SAPPHIRE Trial)
• Only 30 day and 6 month follow up
– (Despite trial ongoing since 2000)
EVA-3S Trial: Limitations
• Experience bias
– Vascular surgeons:
– Required 25 CEAs in the year prior to study entry
– Endovascular physicians:
– Required 12 carotid stents or 35 “supra-aortic
stents” with at least 5 carotid stents
–Or, Allowed to receive training and credentialing
“under supervision” as they enrolled patients in the
trial
– Allowed to use new stents after only two cases
EVA-3S Trial: Limitations
• Enrollment Bias…?
– Total CEA case volumes were not discussed
– Estimated 15% or less of all patients
randomized
– Thirty hospitals
– Assuming only 1 vascular surgeon per hospital
with the enrollment criteria minimum 25 cases/yr
– 4.75 years of enrollment = 3562.5 patients
What will CREST teach us that we
don’t already know?
– CREST: Randomized CAS vs. CEA
– Started in 2000, >100 centers
– Plans to enroll 2500 patients
– Enrollment- around 1700
– 1387 lead-in cases
– 789 carotid stents reported in November 2004
– 30 day stroke and death = 4.6%
– 30 day MI = 1.1%
What will CREST teach us that we
don’t already know?
– Differences from EVA-3S
– Distal Embolic Protection
– MI rates are monitored
– Dual antiplatelet therapy in all patients
– Long term follow up
– More rigorous interventionalist credentialing
– CREST is now more important than ever
– Challenges to Recruitment are present
Conclusions
• CAS and CEA are complementary…the patient must
have every technical option
• Asymptomatic patients deserve treatment…we don’t
know which is best yet
• Low-risk patients should be enrolled in further trials!
CREST, ACT 1…
• We are beginning to understand which pts are at
high risk for CAS….AVOID them!!!!
Future Perspectives:
The War Against Stroke
How Are We Doing??
Who Will Treat Acute Stroke?
• 750,000 CVAs per year and growing
• ~ 250 neurointerventionalists
• ~ 60 endovascular neurosurgeons
• ~ 5 endovascular neurologists
• 5,000 interventional cardiologists
How Do We Get There ?
• Training
• Technology
• Collaborating
Barriers
• Societal
• New Anatomy
• Technology
Collaboration
Subspecialty Strengths
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Neurology
Radiology
Vascular surg
Vascular med
Cardiology
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End organ cognitive
Imaging/cath skills
Own CEA market
Cognitive/imaging
Cath/angioplasty skills
Clinicians
Industry partners
Clinical research
We Will Win the War on Stroke
And…
Cardiologists Will Treat Stroke
Simulator Training Model
Commercial Pilot
• Mandatory yearly
training
• 60 hours
simulated
instrument training
• 60 hours actual
instrument training
Col. Chester Griffin
Director, Simulator Training
AW Certification - USAF
Flight Simulation
Three Components
• Tactile (haptics)
• Procedural
• Complications
Sound Familiar ??
Mentice Simulator
Illustrative Case
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27 year old female
Cesarean delivery 8 weeks prior
Ground level fall and head impact
No LOC, No seizure
Acute onset right neck and head pain
Left upper extremity weakness
Slurred speech
Illustrative Case
• Meds: Oral contraceptives
• In ED: NIHSS = 11
• Left facial weakness, dysarthria, left upper
extremity weakness, left sided anesthesia
• Head CT: no acute trauma
• Head CT perfusion…
Original CT Perfusion
Time to Peak
Emergent Angiogram
Acute RICA occlusion
Heparin 4000
 ACT >250
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Microcatheter Injections
Nautica
microcatheter
Transcend exchange
microwire
Carotid Stent
BMW wire to
supraclinoid ICA
Xpert stent 4 x 40
Still occluded proximally
Xpert stent 5 x 40
No overlap
Xpert stent 5 x 30
Acute MCA Occlusion
Merci Clot Retrieval
… Integrilin
Neuroform Stent for Failed Merci
• Renegade
microcatheter
• Neuroform
(4 x 20)
loaded into
microcatheter
Follow Up CT perfusion
Two Month Follow Up
Mild Dysmetria
Left Arm Paresthesias
Thank You!