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SEMINAR

ATHEROSCLEROTIC

CAROTID ARTERYDISEASE

DR. BARUN KUMAR

17.08.2011

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ATHEROSCLEROTIC CAROTID ARTERY

DISEASE

CAROTID ARTERY is affected by many disorders.

The most frequent cause is atherosclerosis, but

other causes include fibromuscular dysplasia(FMD), cystic medial necrosis, arteritis, anddissection.

Atherosclerosis is a systemic disease, andpatients with this typically face an escalated risk ofother adverse cardiovascular events, includingmyocardial infarction (MI), peripheral arterial

disease (PAD), and death.

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CAROTID ATHEROSCLEROSIS

The proximal internal carotid artery and the

carotid bifurcation are most frequently involved.

However, the origin of the middle cerebralartery, the distal carotid artery, and the carotid

siphon may also be affected.

Ulceration frequently occurs, placing the patient

at higher risk for embolization or thrombosis

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Risk factors for carotid artery

atherosclerosis

Hypertension

Hypercholesterolemi

a Smoking

Diabetes mellitus

Obesity

Family history

The risk of stroke from carotid disease is

highest in patients who have recentlysustained a reversible neurologic event, such

as a transient ischemic attack

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Signs/symptoms of carotid

vascular disease

TIA (Transient Ischemic Attacks): focal neurologicdefects with resolution of symptoms within 24 hours

RIND (Reversible Ischemic Neurologic Deficit):transient neurologic defects lasting 24-72 hrs.

Amaurosis fugax: temporary blindness in one eye,frequently described as curtain coming down due to

microemboli in retina.

CVA (Cerebrovascular accident): neurologic deficitwith permanent brain damage

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Outcome in patients with

asymptomatic neck bruits

prospectively followed 113 asymptomaticpatients

with carotid stenosis 75% (Doppler)

1 year 18% had ischemic cerebrovascular events

over of these events strokes (5.5%)At 2 years 22% had ischemic cerebrovascular

events

In patients with less than 75% stenosis

1 year 3%

2 years 6%

Chambers BR, Norris JW. Outcome in patients with asymptomatic neck bruits. N Engl J Med 1986;315:860-865

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Outcome in patients with

asymptomatic neck bruits 1986

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Evaluating carotid disease

Duplex Doppler ultrasonography

Carotid Doppler ultrasonography

Transcranial Doppler

Magnetic resonance angiography (MRA)

Carotid angiography (gold standard)

Sensitivity/specificity of noninvasive tests to

predict stenoses >70% is 83-86%/89-94%

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STROKEEpidemiology

>50% of the 731,000 strokes/yr in US results from extracranialatherosclerotic carotid artery disease.

Account for 160,000 deaths per year in the United States.

Leading cause of disability.

Half of the patients that survive a stroke are permanentlydisabled.

3rd. Leading cause of death after CAD & cancer in US.

Ischemic events are four times more frequent than hemorrhagicevents.

Atherosclerotic extracranial carotid artery disease usually causesymptoms as a result of embolic events.

Carotid occlusive disease accounts for nearly one third of allischemic stroke cases.

The incidence of ischemic strokes increases with age (33% ifage 45 years and 80% if age 50 years).

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How are TIA and stroke

related?

Pt. with TIA:

1 in 20 ( 5% ) chance of stroke within 30

days

25% will have recurrent CVA within 1 yr

35% of patients with a TIA will have a stroke in

their lifetime

50% of these will occur in the year following firstTIA

After first year stroke risk is 5% per year

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Stroke

Prognosis

80% survive initial event

29% regain normal function

36% return to work 18% unable to work, but can take care of themselves

4% require custodial care

Natural history

only 50% of stroke victims will be alive at five

years.

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What is the risk of stroke with asymptomatic

carotid stenosis?

Rates of stroke among asymptomaticpatients with carotid stenosis of at

least 80% of the luminal diameter are

approximately 3.5 to 5.0% per year.

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Medical Treatment

Both systolic and diastolic blood pressureindependently related to stroke incidence

6mm reduction in DBP produces 42% reduction instroke rate

Tx of isolated systolic hypertension in patients over 60reduces stroke incidence by 32%

Smoking cessation

Relative risk 1.5-2.2

Serum lipid levels

have not been shown to affect stroke rate but lowlevels slow progression of atherosclerosis

Biller J, Feinberg WM, Castaldo JE, et al. Guidelines for carotid endarterectomy: a statement for healthcare professionals from a special writing

group of the stroke council, american heart association. Circulation 1998;97:501-509

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Medical Treatment

Alcohol consumption

Heavy alcohol use associated with excessive

stroke risk

Moderate consumption may have no or a slightlyprotective effect

Antiplatelet therapy

23% reduction in stroke with aspirin compared to

placebo in patients with history of TIA/stroke

Also 22% reduction in MI/death

Biller J, Feinberg WM, Castaldo JE, et al. Guidelines for carotid endarterectomy: a statement for healthcare professionals from a special writing

group of the stroke council, american heart association. Circulation 1998;97:501-509

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Comparison of measurement of ICA stenosis using NASCET

(angiographic) criteria or ECST (Duplex ultrasound) criteria.

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Carotid Endarterectomy

(CEA)Surgical removal of the inner layer of the carotid

artery when narrowed by atheromatous intimal

plaques

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Carotid endarterectomy

Performed through neck incision, usually along

sternocleidomastoid muscle

Proximal and distal control of artery is obtained

While patient is heparinized, internal andexternal carotid arteries are clamped

Longitudinal arteriotomy is performed, carotid

plaque is removed, and vessel is closed over apatch

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North American Symptomatic Carotid Endarterectomy

Trial (NASCET)

Randomized trial of CEA vs anti-platelet therapy

50 centers in US and Canada

1987-1996

659 patients with stenosis >70%

2226 patients with stenosis < 70%

Patients:

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NASCET.NEJM.19

91

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NASCET 1998

Does CEA benefit symptomatic pts with

stenosis

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NASCET 1998

CEA in symptomatic patients with 50-69%

yields only moderate reduction in risk of stroke

and provided no benefit to patients with

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778 symptomatic patients / 3 yrs

Stenoses > 70%

Risk of CVAClinical treatment = 16,8%

Surgical treatment = 2,8%

p < 0,001

Risk CVA/peri-operatory deaths =7,5%

ECST (European Caro tid Su rgery Trials)

Lancet 1991;337:1235

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Can CEA reduce the stroke risk in

symptomatic patients?

CEA reduces the risk of any stroke from 25% to

10% at two years in patients with symptomaticstenosis of 70% (NASCET)

Can CEA reduce the stroke risk in

asymptomatic patients?

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Veterans Affairs Trial, 1993

Asymptomatic Carotid Stenosis Veterans

Administration Study

11 centers, 1983-1991

444 men with asymptomatic carotid stenosis 50% stenosis or more (angiogram)

Evaluated combined incidence of TIA, Amaurosis

Fugax, and stroke

Randomized to optimal medical treatment alone

vs. optimal medical treatment plus carotid

endarterectomyHobson RW 2nd, Weiss DG, Fields WS, Goldstone J, Moore WS, Towne JB, Wright CB. Efficacy of carotid endarterectomy for asymptomatic carotid

stenosis. The Veterans Affairs Cooperative Study Group. N Engl J Med. 1993 Jan 28;328(4):221-7.

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Veterans Affairs Trial, 1993

All patients followed for an average of 48

months

Incidence of ipsilateral neurologic events

8% CEA

20.6% medical group

Stroke/death rate within 30 days not different

between groups

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Veterans Affairs Trial, 1993

Incidence of Neurologic End Points for Ipsilateral Events.

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Veterans Affairs Trial, 1993

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Asymptomatic Carotid Atherosclerosis Study

(ACAS)

Randomized trial of CEA vs anti-platelet therapy 39 centers in US and Canada

1988-1993

1662 patients

Patients

Age 40-79 Exclusion criteria:

Severe comorbidities disease likely to cause death

w/in 5 yrs Any cerebrovascular event Contra-indication to aspirin

Carotid artery stenosis >60% stenosis

Defined by angiography ordoppler US Same angiographic definition

as NASCET

Medical treatment:

325mg aspirin daily

Recommendations on risk factorreduction

No angiography required

Surgical treatment:

Aspirin & risk reduction

Angiography required CEA

Peri-operative risk of stroke or death:

Surgery: 2.3%

5 strokes secondary toangiography

Medical: 0.4%

5-year results: 6% absolute risk reduction for stroke

Conclusions:

CEA recommended for patientswith > 60% stenosis

In centers with low peri-operativemortality and stroke rates (

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Asymptomatic Carotid Surgery Trial

(ACST)

Randomized study of immediate vs. indefinitedeferral of CE

5 five year follow-up at 126 centers in 30 countries

% diameter reduction stenosis by carotidultrasound

Eligibility = carotid artery diameter reduction of at

least 60% on ultrasound and no symptoms withinthe past six months

Enrollment 19932003 planned 10 year follow-up

3120 randomized patients - 2 groups of 1560 each

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Perioperative events (stroke and death within 30days) and the non-perioperative strokes combined Net 5 year risks were 6.4% (immediate CE) versus

11.8% (deferred CE) for all strokes; 3.5% vs. 6.1% forfatal or disabling strokes

Gain mostly in non-perioperative carotid territoryischemic strokes

The benefit was seen in both contralateral and

ipsilateral carotid-territory strokes

Asymptomatic Carotid Surgery Trial

(ACST)

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Subgroup analyses showed

benefits were significant for those < 65 years, thosebetween 65 and 74 years, but uncertain for those > 75years

Men and women both benefited but there were only atotal of 40 non-perioperative strokes in women so theresults were not as definite (p=0.02)

5 year benefit of CE appeared to be as great for thosewith six months previously (7.1% and 4.6%absolute five year gain, respectively)

Asymptomatic Carotid Surgery Trial

(ACST)

C li ti f tid

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Complications of carotid

endarterectomy

Cardiac events

Postoperativestroke

Hyperperfusion

syndrome Nerve injury

Bleeding

Infection

Parotitis

Re-stenosis

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Hyperperfusion syndrome

Cerebral hyperperfusion is the leading cause ofintracerebral hemorrhage and seizures during the firsttwo weeks following CEA.

Causes changes in low-flow carotid vascular bed.

Small vessels compensate by dilating, then cannot re-

constrict properly and therefore cannot protectvascular bed

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Nerve injury

Nerves at risk for injury during CEA include:

Vagus nerve

Recurrent laryngeal nerve

Facial nerveGlossopharyngeal nerve

Hypoglossal nerve

Branches of trigeminal nerve

management vs carotid endarterectomy for

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management vs. carotid endarterectomy for

ipsilateral

stroke prevention in patients with carotid artery

stenosis

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Conditions associated with an

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Conditions associated with anincreased operative risk for carotid

endarterectomy

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Can CEA reduce the stroke risk in

asymptomatic patients?

CEA reduces the risk of any stroke or death from

11% to 5% at five years in patients withasymptomatic stenosis of 60% (ACAS)

What about stenting?

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Patients with high risk of stroke presentalso with high risk for surgical treatment

Brown et al. J Vasc Surg, 2003; 37:32

Gasparis et al. J Vasc Surg 2003; 37:40

High risk

patientsEndovascular

Treatment

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Carotid artery stenting procedure. Following engagement of the common

carotid artery (CCA) with a guiding catheter or long sheath, the lesion in the

internal carotid artery (ICA) is passed with a wire or with the filter emboli

protection device (A). Subsequently, a self-expanding stent is deployed, usually

covering the carotid bifurcation (B and C). Thereafter, a balloon post-dilatation

is performed to achieve good stent expansion (D). ECA, external carotid artery.

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Conditions associated with increased procedural risk

and contraindications for carotid artery stenting

Carotid angioplasty and

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Carotid angioplasty and

stenting

The first case reports of carotid artery

angioplasty were reported in the early 1980s.

Carotid angioplasty and

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Carotid angioplasty and

stenting

Roubin GS, Yadav S, Lyer SS, et al. Carotid stent supported angioplasty: a neurovascular intervention toprevent stroke. Am J Cardiol 1996;78:8-12.

The first large series of carotid angioplasty and

stenting was reported by Roubin et.al. in 1996

They preformed angioplasty in 107 patients

deemed too medically/anatomically unstable toundergo endarterectomy.

10% combined stroke/death rate

Carotid angioplasty and

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Carotid angioplasty and

stenting

In 2000 a large multicenter report (14 groups)

in which 358 arteries in 338 patients with

restenosis after CEA was published.

5 year follow-up Stroke rate 3.7%

Mortality 1.1%

Adverse events 4%

New G, Roubin GS, Iyer SS, et al. Safety, efficacy, and durability of carotid artery stenting for restenosis following carotid endarterectomy: a

multicenter study. J Endovascul Ther 2000;7:345-352.

Carotid angioplasty and

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Carotid angioplasty and

stenting

Mathias K, Jager H, Hennigs S, et al. Endoluminal treatment of internal carotid artery stenosis. World J

Surg 2001;25:328-334.

In 2001 Mathias et al. presented data on over

3,000 carotid artery stents (CAS).

Stroke rate 2%

Complication rate 3%

These and other series demonstrated that

stenting could be preformed with anacceptable complication rate.

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3 types of studies available to review efficacy

of stenting

Case series

Industry sponsored registriesRandomized trials

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In

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Case Series

51% patients symptomatic

>97% successfully stented

64% evaluated by neurologist

After 2002 embolic protection devices (EPDs)

widely utilized

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There is considerable evidence of

embolization during carotid angioplasty

DeMonte et al.J Neurosurg. 1989;70:138

Ohki, T et al. J Vasc Surg. 1998;27:463

Industry sponsored registries of

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Industry-sponsored registries of

CAS

Industry sponsored registries of

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Industry-sponsored registries of

CAS

Presented at national meetings but not

published in peer reviewed journals

30 day stroke rates 2%-7%

30 day stroke, MI, death rates 3%-8%

27% of patients symptomatic

CEA/CAS Randomized Controlled

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CEA/CAS Randomized ControlledTrials

ICSS

CREST

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CEA/CAS BACKGROUND INFORMATION

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CEA/CAS BACKGROUND INFORMATION

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Randomized trials

All used independent neurologist examinations

After 2001, all used EPDs

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WALLSTENT TRIAL

219 patients

No protection

No antiplatelet therapy

Surgical

4,5%

Endovascular

12,1%Risk CVA/death

Trial was interrupted

Stroke 2001;32:325

The Carotid and Vertebral Artery

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Transluminal Angioplasty Study

(CAVATAS)

First multicenter RCT comparing CEA and CAS.

Stenting was rolled late into the trial. 24 centers in Europe,Australia, and Canada enrolled 504 pts.

High-risk surgical pts were excluded. Mixed symptomatic andasymptomatic pts.

253/504 randomized to CEA and 251/504 to endovascular tx (65received stents, 26%). No distal protection device.

Results: No statistically significant difference between both arms inthe rate of stroke, death or MI within 30 days and 1-year stroke ordeath rates

Encouraging results generated interest in CAS, and inspired morestudies to be undertaken.

Lancet. 2001

CAVATAS

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CAVATAS: Endpoint events at 30 days

Carotid angioplastyand stenting

Endpoint

CAVATAS investigators. Lancet2001; 357: 1729-37.

CAVATAS

Disabling strokeor death

Any stroke > 7days, death

Carotidendarterectomy

6.4%

p value

5.9% NS

10.0% 9.9% NS

CAVATAS

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CAVATAS: Complications

Carotid angioplastyand stenting

Endpoint

CAVATAS investigators. Lancet2001; 357: 1729-37.

CAVATAS

Cranialneuropathy

Major groin orneck hematoma

Carotidendarterectomy

0 (0%)

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Carotid Revascularization Using Endarterectomy or

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Carotid Revascularization Using Endarterectomy or

Stenting Systems (CaRESS)

Prospective non-randomizedcohort study

14 centers in US

397 patients

254 CEA, 143 CAS

Standard CEA versus CAS with

cerebral protection device

Patients:

Similar patient demographics

68% asymptomatic

>90% with >75% stenosis

Significantly more prior CEA or stent

in the CAS arm

Peri-operative stroke or death: CEA: 2.4%

CAS: 2.1%

4 year follow up results:

Any stroke:

CEA 9.6%, CAS 8.6% Death/ non-fatal stroke:

CEA 26.5%, CAS 21.8%

Restenosis:

Significantly higher in CAS arm

Conclusion:

Proof of principle that CAS withdistal protection should becompared to CEA in a broadpatient sample in a randomizedtrial

J Endovasc Ther 2003 & 2009

SAPPHIRE 2004

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SAPPHIRE 2004

Stenting and Angioplasty with Protection for

Patients at HIgh Risk for Endarterectomy

(SAPPHIRE) trial

Data at 30 days and 1 year & 3 yearEPDs used on all patients

334 patients

50% symptomatic stenosis

80% asymptomatic stenosis

Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid artery stenting verses endarterectomy in high-risk patients. N Engl J Med 2004;

351:1493-1501.

SAPPHIRE 2004

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SAPPHIRE 2004

SAPPHIRE

High risk for CEA

Clinically significant heart disease

Severe pulmonary disease Contralateral carotid occlusion

Contralateral laryngeal nerve palsy

Previous radical neck surgery or radiation therapy

Recurrent stenosis after CEAAge > 80 years

Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid artery stenting verses endarterectomy in high-risk patients. N Engl J Med 2004; 351:1493-1501.

SAPPHIRE 2004

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SAPPHIRE 2004

Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid artery stenting verses endarterectomy in high-

risk patients. N Engl J Med 2004; 351:1493-1501.

SAPPHIRE Randomized to CEA or CAS

30 day stroke/MI/death rate 4.4% CAS

9.8% CEA

1 year stroke/MI/death rate

12% CAS

20% CEA

High rates in CEA group secondary to high riskpatients

Conclusion CAS with EPD not inferior to CEA in highrisk patients

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SAPPHIRE 2004

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SAPPHIRE 2004

Flaws with SAPPHIRE Supported by Cordis Corp. manufacturer of stent used in

study [use of a self-expanding,nitinol stent (Smartor Precise, Cordis) and an emboli-protection

device (Angioguard or Angioguard XP EmbolicCapture Guidewire, Cordis)] 747 pts evaluated only 334 randomized (406 entered into

stent registries, 7 referred for CEA)

Stopped after 334 pts out of planned 2,900 pts enrolleddue to competing nonrandomized registries

Troponin based MI

non-Q-wave MI have 27 fold increased risk of MI in the next 6months

This was not borne out in the long-term outcomesGurm, HS, Yadav JS, Fayad, P M.D.et.al.Long-Term Results of Carotid Stenting versus Endarterectomy in High-RiskPatients. N. Engl. J. Med. 2008;358:1572-9

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SAPPHIRE 2004

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SAPPHIRE 2004

SAPPHIRE was used to gain FDA approval ofthe Cordis stent

6 cardiologists, 2 interventional radiologists, 2

vascular surgeons, 1 neurologist on panelApproved 6 to 5

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SPACE

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SPACE Lancet 2006

To establish noninferiority for CAS in symptomatic pts with CS 50% and with low surgical risk.

Multicenter randomized trial throughout Germany, Austria, andSwitzerland.

Primary endpoints were ipsilateral ischemic stroke or deathfrom randomization to 30 days post procedure.

All patients received aspirin preprocedure.

1200 pts randomized, 595 to CEA and 605 to CAS.

SPACE

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SPACE Lancet 2006

At 30 days, ipsilateral stroke or death was not different,6.35% for CEA and 6.8% for CAS (P = .09).

Distal protection used only in 27%; subgroup analysisshowed no difference between pts with cerebral protectionand those without. Stroke 2009

The trial was stopped as result of interim analysisdemonstrated that 2500 patients would be needed to reachsignificance and determine noninferiority of CAS given theresults up to that point.

The SPACE steering committee acknowledged a lack offunds to expand enrollment to 2500 and thereforesuspended the trial.

In the final analysis, the SPACE trial failed to provenoninferiority of stenting versus endarterectomy asmeasured b stroke/death rates at 30 da s ost rocedure

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SPACE Lancet Neurol 2008

1214 patients were randomly assigned (613CAS and 601 CEA).

At 2 years follow-up:

Primary and secondary endpoints were similar. Recurrent stenosis (70% ECST) defined by

ultrasound was more frequent in CAS group. Only two

incidences of recurrent stenosis after carotid artery

stenting led to neurological symptoms.

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SPACE

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SPACE 2006,2008

Interpretation:Symptomatic pts with CS and low surgical risk, SPACEfailed to prove noninferiority of CAS for lack of powerfrom 1214 patients recruited. However, there was no

statistical difference in the rate of outcome events

These results can be interpreted differently:

A vascular surgeon may point out that an equal effect betweenCEA and CAS was not shown with SPACE because equivalence

was missed (P0.09, one-sided value for noninferiority). Interventionalists have focused on the fact that there was no

statistical difference in the outcome event rates between CEA andCAS (P0.81, ChiSquare test)

EVA-3S N Engl J Med 2006

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EVA-3S N Engl J Med 2006

Similar to the SPACE trial, RCT designed to assess noninferiority of CASversus CEA in low-risk, symptomatic patients with CS 60%.

Multicenter study conducted in France. Primary endpoint was 30-day

stroke or death.

The study was stopped after enrollment of 527 pts for reasons of safety

and futility.

Primary endpoint was 3.9% CEA vs. 9.6% CAS (P = .01).

Protection devices was not required initially. Pts treated without protectionhad 25% rate of stroke or death at 30 days (5/20), prompting protocol

changes.

CAS operators had unequal experience compared to surgeons performing

CEA.

EVA 3S N Engl J Med 2006

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EVA-3S N Engl J Med 2006

Risk was 9.6% higher than other RCTs. The absolute risk increase ofstenting was 5.7%, and for every 17 cases treated with CAS ratherthan CEA, 1 additional stroke or death occurred at 30 days postprocedure.

The overall incidence of disabling stroke within 30 days was 3.4%for CAS, 1.5% for CEA.

A significantly greater proportion of strokes occurred on the sameday of the procedure in the stenting group than in the surgical group

(P = .05).

Conclusion: Patients with symptomatic CS of 60%, CAS wasinferior to CEA with respect to the incidence of stroke and death at30 days post procedure??

ICSS/CAVATAS 2 L t 2010 F b 25

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ICSS/CAVATAS-2Lancet. 2010 Feb 25.

International Carotid Stenting Study: An interim analysis.

CAS vs. CEA in patients with symptomatic carotid stenosis.Patients arelow-risk equally suited for CAS or CEA

Multicentre, international, randomized controlled trial

The primary outcome: 3-year rate of fatal or disabling stroke inany territory, which has not been analyzed yet.

The main outcome measure for the interim safetyanalysis:120-day rate of stroke, death, or procedural MI.Analysis was by intention to treat (ITT).

ICSS/CAVATAS-2

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1713 patients (CAS 855; CEA 858).

Disabling stroke or death: CAS 4.0% vs. CEA3.2% (hazard ratio [HR] 1.28, 95% CI 0.77-2.11).

Stroke, death, or procedural MI: CAS 8.5% vs.CEA 5.2% (HR 1.69, 1.16-2.45, p=0.006).

Risks of any stroke (CAS 65 vs CEA 35 events;HR 1.92, 1.27-2.89) and all-cause death (CAS 19vs CEA 7 events; HR 2.76, 1.16-6.56)

ICSS/CAVATAS 2

ICSS/CAVATAS-2

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Procedural MI: CAS 3 all fatal; CEA 4 all non-fatal.

Cranial nerve palsy CAS 1; CEA 45.

There were fewer hematomas of any severity in thestenting group than in the endarterectomy group(31 vs. 50 events; p=0.0197).

Conclusion: Completion of long-term follow-up is

needed to establish the efficacy of CEA vs. CAS.

Meanwhile, CEA should remain the treatment ofchoice for patients suitable for surgery.

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CREST

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CREST

Carotid Revascularization Endarterectomy versusStenting Trial

Prospective randomized CEA vs. CS as prevention

of stroke in sxs & asxs patients Composite primary endpoint of any periprocedural

stroke/MI/death OR ipsilateral stroke on f/u

n = 250217 centers North America (CEA 1240, CS

1262)

CREST

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Primary and Secondary Endpoints

Primary endpoint Peri-procedural a composite of:

Any clinical stroke

Myocardial infarction

Death Post-procedural

Ipsilateral stroke up to 4 years

Secondary endpoint Differential efficacy based on symptomatic status,

gender and age

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CREST: Results

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CREST: Results

Primary endpoint

Carotid angioplasty/stenting: 7.2% / 4 years

Carotid Endarterectomy: 6.8% / 4 years

P value 0.51

Peri-procedural stroke

CAS 4.1 % CEA 2.3% HR 1.79, p=0.01

Peri-procedural MI

CAS 1.1% CEA 2.3% HR 0.50, p=0.03

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FDA Approved Devices

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FDA Approved Devices

SAPPHIRE trial by Cordis FDA approval of angioguard system in April 2004

ARCHeR registry by Guidant

FDA approval for Accunet/Acculink system inAugust 2004

SECURITY registry by Abbott

FDA approval for Xact/Emboshield system in

September 2005

Pre- and Postprocedural Checklist for Carotid

P d

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Procedures

The Type I aortic arch is characterized by the origin of all 3 major vessels in the horizontal plane defined byf f f

Types of AorticArch

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the outer curvature of the arch. Type I arch has the origin of all the great vessel within one diameter of theICA away from each other.

In Type II, the brachiocephalic artery originates between the horizontal planes of the outer and inner

curvatures of the arch. It has the take-off of the brachiocephalic artery >1 ICA diameter away from the othergreat vessels

In Type III, the brachiocephalic artery originates below the horizontal plane of the inner curvature of thearch.

Bovine Aortic Arch

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A frequent variant ofhuman aortic arch

branching in which the

brachiocephalic and

left common carotid

arteries share acommon origin.

Occurs in about 27%

of people

This anatomy is not

generally found in

cattle, so the term

bovine arch is a

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The Circle of Wil l is

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The circle of Willis is an anastomotic network at the baseof the brain, surrounding the optic chiasm and thepituitary stalk .

The posterior communicating artery (PCOM), arisingfrom the terminal portion of the supraclinoid ICA,provides the major collateral connection between theanterior circulation (from the ICA) and posterior

circulation (to the posterior cerebral artery).

Although the PCA typically arises from the basilar arteryof the posterior circulation, the PCA could arise directlyfrom the ICA, without any PCOM connection of the

Collaterals

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From the external carotid artery to the internal carotid artery(via theinternal maxillary branch of the external carotid artery and thesuperficial temporal artery to the ophthalmic branches of the internalcarotid artery).

From the external carotid artery to the vertebral artery(via the occipital

branch of the external carotid artery).

From the vertebrobasilar arterial system to the internal carotid artery(via the posterior communicating artery), and

Between the left and right internal carotid arteries(via theinterhemispheric circulation through the anterior communicatingartery).

The configuration of the circle of Willis is also highly variable, with acomplete circle in fewer than 50% of individuals.

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Pre-operat ive med ication

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Pre operative med ication

The patient should be adequately hydrated as withall vascular catheterisation procedures.

Aspirin and Clopidogrel need to be initiated at

least 24 hours prior to the procedure. A loadingdose of 300 mg of each is given if the patient is noton them regularly, with 75 mg daily thereafter.

Anti-hypertensive medication is reviewed, and thebeta-blocker stopped for the day of the procedure.The aim is to have a systolic pressure between120180 mmHg at the start of the procedure.

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Carotid angiography contd

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Carotid angiography contd

For selective angiography of the carotid and/orvertebral arteries, the most commonly used cathetersare the Vitek, Berenstein , Sidewinder, Simmons,Headhunter, Bentson and Mani catheters.

May use angled hydrophilic guide wire (i.e., Glidewire,Terumo) to assist the catheter past the innominatebifurcation and selectively into the right carotid.

One may take one cine run of the innominatebifurcation in the RAO 40 projectionto excludedostial carotid disease prior to engaging the carotid.

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Carotid angiography contd

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Ca o d a g og ap y co d

The usual camera angle of the right carotidsystem is RAO 30 to 40 and RAO 90; this willprovide clear visual separation of the bifurcation ofthe right internal and right external carotid artery.

For anterior cerebral circulation, RAO 90 and APcranial 30 (known as Townes View), are takenof the whole skull.

Take care to record a prolonged cine to ensurecapture of the venous phase as well.

Carotid angiography contd

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g g p y

After all images of the right carotid system have been successfully recorded, thecatheter is disengaged and inserted into the left common carotid artery.

The usual angles for imaging the left carotid system are LAO 30to 40, and

LAO 90;this allows separation of the bifurcation of the left internal and left

external carotid artery.

For anterior cerebral circulation, LAO 90and AP cranial 30are taken of the

entire skull, making sure to visualize the venous phase.

If the suspected target of intervention is the right carotid artery, it is

recommended to perform the angiography of the left carotid first to avoid

cannulating the right carotid artery twice.

CAROTID STENTING

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Once the decision is made to proceed with carotid stenting,intravenous anticoagulation is given. Angiomax (Bivalirudin)and unfractionated heparin are most commonly used.

If heparin is used, the medication should be administered toachieve an activated clotting time (ACT) greater than 200seconds ( between 200-250).

The ACT is tested 5 minutes after heparin has been administered,

and every half hour thereafter, until the interventional portion ofthe procedure has been completed.

Additional heparin may be needed to maintain the ACT

CAROTID STENTING

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Additional Equipment needed for the interventionalportion of the procedure includes a guiding catheter or90 cm guide sheath, embolic protection device, a self-expanding stent, and an angioplasty balloon.

Depending on physician preference, a guide catheter(An 8Fr guide usually a right coronary guide isadvanced into the ascending aorta over a hydrophilic0.0035 wire) or 90 cm guide sheath long enough toextend from the common femoral artery to the proximal

portion of the common carotid is used.

The diagnostic catheter is exchanged for the guidingcatheter or sheath with the use of a stiff exchange wire

with a very soft tip (a stiff Amplatz-type wire).

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Strategies for emboli protection devices in carotid artery stenting. On the

left panel, a filter device is demonstrated; in the middle, a distal balloon

occlusive device; and in the right panel, a proximal occlusive device. CCA,

common carotid artery; ICA, internal carotid artery; ECA, external carotid

artery.

EMBOLIC PROTECTION DEVICES USED FOR CAROTID

ARTERY STENT (CAS) PROCEDURES

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Embolic protection device

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Distal protection is the most accepted technique currently.

The most commonly used devices are usually a steerable .014-inchguide wire with a self-expanding filter basket at the end, designed tocapture any debris that may become dislodged from the lesion duringthe intervention.

The distal protection device must be sized accurately.

If the device is sized too small for the carotid artery, the risk of debrisflowing past the basket resulting in transient cerebral ischemia or

infarction exists.

Correct placement of the basket is well distal to the target lesion,preferably in a straight portion of the artery, allowing room to safelypass the balloon and stent without the basket or wire moving duringexchanges.

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FILTER

WIRE

Protection in Benign Lesion

is Worthwhile

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is Worthwhile

Predilatation

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Predilatation can be performed to ensure that astent delivery system can safely pass through the

stenosis.

Safe predilatation is done by undersizing the

artery; if the lumen of the artery is 6 mm in

diameter, the predilatation balloon should

measure about 4 mm.

The balloon is inserted over the distal protection

device wire.

Predilatation

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If the lesion is tight, with less than a 2 mmdiameter, or looks calcified, the pre-dilatation witha 3 mm 20 mm balloon is recommended.

Direct stenting may be performed for less severestenoses.

It is vital to give atropine 600 micrograms prior toballoon inflation. Failure to do so will result is

bradycardia and hypotension which can bedifficult to manage and may be prolonged.

Choosing a stent

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A closed cell design will improve lesion coverage if a lot ofdebris is expected, but will not be as flexible as an open celldesign.

A stainless steel stent (Carotid Wallstent, Boston) is likely tohave more radial strength, but will not be as conformable as a

nitinol stent (e.g. Precise stent, Cordis, or Acculink, Guidant).

When choosing the stent, the size of the common carotid arteryproximal to the lesion, as well as the internal carotid arterydistal to the lesion, must be determined.

In regards to stent diameter, it is usually best to oversize thestent. Oversizing by 12 mm compared to the vessel sizeallows the stent to expand after postdilatation, decreasing therisk of migration. For example, if the vessel is 6 mm, an 8 mmstent is appropriate.

Choosing a stent

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g

The length of the stent is chosen in the same way; if thelesion length is 20 mm, a 30 or 40 mm stent is chosen.The stent should extend past both the proximal anddistal portion of the lesion.

The role for tapered stents (designed to be smaller inthe ICA section than the CCA section) is not clear(Acculink, Guidant).

Self-expanding stents are used almost exclusively.

It appears that stenting across the ECA origin does notmatter clinically. Since many ICA stenoses extend intothe carotid bifurcation, the norm is to stent into the CCA

from the ICA.

Indications for Use of Balloon Expandable

Stents

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Stents

Covered Stents In The Carotids

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Rupture

Dissection

Post CEA Pseudoaneurysm Blunt Trauma

Penetrating Trauma

Stent deployment

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When the stent is ready for deployment, it is

optimal to initially deploy only one-third of the

stent, and double check placement due to thefact most self-expanding stents tend to jump

forward during deployment.

If satisfied with stent placement, the stent is

then fully deployed, and the delivery system is

removed.

Postdilatation

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Postdilatation is performed to ensure properexpansion of the stent and effectively dilate anyremaining plaque against the wall of the artery.

The size of the postdilatation balloon should be the

size of the vessel at the distal deployment edge of thestent.

Post-dilatation is usually required to allow the stenosisto be reduced to

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Before inflating the balloon, make sure that the staff are readyand alert.

At this juncture, intravenous atropine sulfate can be givenprophylactically to maintain the heart rate and counter the bloodpressure drop normally seen during high-pressure ballooninflation.

Intravenous fluids are open to the patient and prepped with apressure bag.

The balloon should be inflated quickly, monitoring both thepatients vital signs and the size of the balloon.

Once full expansion of the stent has been achieved, the balloonis deflated immediately.

Before removing the balloon, angiography should beperformed to ensure that no perforation or dissection of the

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performed to ensure that no perforation or dissection of thevessel has occurred.

The balloon is then carefully removed, followed by the distalprotection device.

With all devices removed, a final set of angiograms isperformed in a minimum of two views.

Poststent cerebral angiography should also be performed toensure the patency of all vessels.

After the procedure the systolic blood pressure should bebelow 140 mmHg. A lower pressure is preferable, especiallyin case of a very tight lesion before stenting and/or in case ofa contralateral occlusion because these patients have ahigher risk of intracranial bleeding.

SUMMARY OF TECHNIQUE TO PERFORM CAROTID

ARTERY STENTING IN STANDARD CASES

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Potential Complications of Carotid Artery Stenting

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TAKE HOME MESSAGES

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CAROTID ATHEROSCLEROTIC DISEASE IS HIGHLYPREVALENT.

OPTIMIZED MEDICAL TREATMENT SHOULD ALWAYS BEGIVEN.

CEA IS STILL GOLD STANDARD DEFINITIVE TREATMENTESP. IN LOW RISK PATIENT & IN EXPERT HANDS.

CAS IS AN ALTERNATIVE OPTION ESP. IN HIGH RISK

CASES.

CASE SELECTION & EXPERTISE IS KEY TO SUCCEESS OFCAS.

DPDs SHOULD ALWAYS BE USED DURING CAS.

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THANK YOU