Journal Club
Ani Balmanoukian and
Peter Benjamin
November 9, 2006
Endarterectomy versus
Stenting in Patients with
Symptomatic Severe Carotid
Stenosis
Mas et al.
NEJM 355;16 October 19, 2006
Background

Carotid Endarterectomy is the standard
treatment for symptomatic or asymptomatic
high-grade(> 60% or 70%) internal carotid
artery stenosis.

Carotid artery stenting has become another
option
Carotid Endarterectomy

NASCET and ECST
trials have demonstrated
the efficacy in
symptomatic patients

Complications include
local nerve injury and
stroke
www.vascular.co.nz
Carotid Stenting




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Less invasive than CEA
Can be done under local
anesthesia and sedation
Less costly than CEA
Risk of stroke and local
complications
Long term efficacy not
well known yet
http://radinfo.musc.edu/~stringes/carotidimage25.jpg

Hypothesis/Goal: Evaluate whether stenting is
not inferior to endarterectomy with regard to
the risks of the procedure and long-term
efficacy in patients with symptomatic carotid
stenosis.

Design: Randomized, noninferiority trial.

Setting: 20 academic and 10 non-academic
centers in France.

Investigators: Each center had to have a team of
physicians consisting of
1 Neurologist
1 Vascular surgeon: had to have performed at least
25 CEAs
1 Interventional physician: had to have performed
at least 12 carotid stenting procedures or at
least 35 stenting procedures in the
supraaortic trunks, of which 5 were in the
carotid artery.

Participants: 527 patients >18 y/o, with history of a
hemispheric or retinal TIA or a nondisabling stroke
within 120 days before enrollment.
Stenosis of 60-99% in the symptomatic carotid
artery.
Exclusion: disabling stroke, nonatherosclerotic
carotid disease, previous revascularization, bleeding
disorder, uncontrolled HTN or diabetes, unstable
angina, life expectancy <2 years.
Figure 1.
Mas et al, Endarterectomy vs. stenting in
patients with symptomatic severe carotic
stenosis. NEJM 2006;355:1660-71

Data Collection: Evaluation by Neurologist at 48 hrs, 30 days,
6 months after treatment and 6 months thereafter.

Outcome:
Primary: Any stroke or death occurring within 30 days after
treatment.
Secondary: MI, TIA, cranial nerve injury, major local
complications, and systemic complications within 30 days.

Analysis: Kaplan-Meier method, intention to treat principle.
Table 1. Baseline Characteristics of the Patients.
Key Points
• Patients overall very similar
• Only differences:
• More patients older than 75 yo in CEA group (40.5%
vs. 32.2%)
• More patients with h/o stroke in CEA group
(20.1% vs 12.6%)
• Higher proportion of contralateral carotid occlusion
in stenting group (none of these had a stroke after
stenting)
Table 3: Risk of stroke or death and other outcomes
within 30 days
Key Points:
• Unadjusted RR of stroke/death is 2.5 for stenting vs CEA
(Number Needed to Harm: 17)
• No significant correlation between RR of stroke/death and
number of patients treated at each center
• No significant difference in stroke/death outcomes
between interventionalists who were experienced, tutored
during training, tutored after training
• Decreased incidence in stroke/death in pts who had
cerebral protection along with stenting vs stenting alone
• RR stroke/death adjusted for age was 2.4, h/o stroke 2.6
• Cranial nerve injury much more likely with CEA (7.7% vs
1.1%)
Conclusions/Implications

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In pts with symptomatic carotid stenosis >60%,
CEA has lower rates of stroke/death through 6
months
These results agree with some (e.g. SPACE), but
not all (e.g. SAPPHIRE) prior studies
Taken together, pending further evidence,
stenting should be limited to symptomatic pts
with >70% stenosis who are high surgical risk
Strengths
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Large, Multicenter RCT
All patients accounted for at conclusion
Groups were similar at start of trial
Weaknesses
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Required minimal experience for
interventionalists doing procedure
Didn’t indicate differences in complications
based on experience
Anesthesiology or periop differences?
No standardization of stenting device used (5
different stents, 7 different cerebral protection
systems used)
Discussion
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What are unique aspects of a noninferiority trial
What is the significance of an intention to treat
analysis
Intricacies in a surgical rct that are unique
How to minimize differences in
surgeon/interventionalist experience?
 How to minimize effects of other aspects (e.g.
anesthesia, postop care, etc)
 Can you standardize experience level differences
between CEA and carotid stenting?
 Any way to blind such a trial?
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References

Mas JL et al. Endarterectomy versus stenting in
patients with symptomatic severe carotid
stenosis. N Engl J Med. 2006 Oct
19;355(16):1660-71.

North American Symptomatic Carotid
Endarterectomy Trial Collaborators. Beneficial
effect of carotid endarterectomy in symptomatic
patients with high-grade carotid stenosis. N Engl
J Med 1991; 325:445-53.