Marvin D. Atkins, Jr., MD

Division of Vascular

Surgery

Temple, Texas, USA

April 2011

Marvin D. Atkins, Jr., MD

Division of Vascular

Surgery

Temple, Texas, USA

April 2011

Carotid Artery Occlusive Disease Update 2011

Carotid Artery Occlusive Disease Update 2011

Stroke in the United StatesStroke in the United States

• Third leading cause of adult death and leading cause of Neurologic Disability in the United States.

Approximately 750,000 new cases per year.

Annual Cost ~$40,000,000,000

Framingham Study – 88% ischemic, 9% intracerebral hemorrhage, and 3% SAH

Estimated that 30% of ischemic strokes are related to carotid disease.

Carotid SurgeryCarotid Surgery• Carotid artery occlusive disease is the

most readily treatable lesion leading to stroke.

• Carotid endarterectomy is the most common operative procedure in peripheral vascular surgery.

Carotid Occlusive DiseaseCarotid Occlusive Disease

Atherosclerosis produces 90% of lesions

• Fibromuscular dysplasia • carotid kinking/coils • extrinsic compression

• Trauma • intimal dissection • vasculitis • radiation

Other causes:

Other CausesOther Causes

Distribution of atherosclerotic occlusive lesions

Carotid Plaque and Embolization

Carotid Plaque

PATIENT PRESENTATION

• Asymptomatic cervical bruit.• Transient hemispheric neurologic deficit• Transient monocular dysfunction

(amaurosis fugax).• Stroke with or without residual deficit.• Acute stroke or stroke in evolution.

Carotid BruitsCarotid BruitsPresent in 5% of the > 50 y/o population.

Only 23% of bruits associated with >50% carotid artery stenosis.

Less than half of hemodynamically significant lesions have a bruit.

Stronger predictor of significant coronary artery disease.

Surgical EmergenciesSurgical Emergencies

Crescendo TIA: escalating frequency with resolution between.

Stroke in evolution: Waxing and waning symptoms without complete resolution between.

• Urgent surgical treatment: improved results with complete recovery in up to 70%.

Completed StrokeCompleted Stroke• Decision to evaluate best determined

by whether another stroke in same distribution would likely impair patient substantially beyond current level

• For small strokes and resolved deficits, surgery can be done sooner than has been recommended in past.

Most of these symptoms are more likely to be a manifestation of cardiac arrhythmias, seizures, migraine, or other non-vascular-

related conditions

Screening Recommendations

Recently published intersociety guidelines JACC

Class I• Known or suspected carotid disease –

Ultrasound (US) recommended as first line screening test

Class 2a• US is reasonable in asymptomatic pts w/ bruit• Annual US in those with >50% stenosis

Class 2b• US may be reasonable in those with CAD, AAA, or PVD

Class 3• Not recommended in asymptomatic pts without risk factors

Medical Management:Recommendations

• Smoking Cessation

• Statin is recommended for all pts with carotid dz to

lower LDL < 100 (Class 1, level B), possibly even

< 70 (Class 2A, level B)

• HTN – below 140/90

• Control of Diabetes to Hba1C < 7

• Antiplatelet recommendations :

Practical Recommendations:

• Aspirin as first line therapy - 325mg for larger patients, 81mg for small pts or those

complaining of bleeding/bruising.• Increase antiplatelet regimen if symptoms

develop- Add Aggrenox (ASA 25mg/Dipyridamole 200mg) BID- or Plavix 75mg QD• Do Not stop antiplatelet agents prior to CEA.- Add statin (Lipitor > Pravachol or Zocor)• Ok to stop if asymptomatic prior to another

procedure. Restart as soon as possible.

Surgical Management:

Evaluation

History• Symptoms• Risk factors

• non-modifiable: age, gender, race, heredity.• modifiable: HTN, tobacco, cholesterol, DM,

cardiac disease.

Physical Examination• Neurologic exam• Bilateral arm pressures• Carotid bruit?• Vascular disease in other territories

Patient EvaluationPatient Evaluation

EVALUATION TECHNIQUES• Search for arterial lesions, coagulopathy,

sources for emboli.• Duplex imaging.• Brain imaging - CT or MRI to determine

areas of cerebral damage or alternative pathology, i.e. tumors, aneurysms, vascular malformations, etc.

• CT Angiography• MR Angiography• Contrast angiography

EVALUATION TECHNIQUESDuplex Imaging

• B-mode ultrasound combined with spectral analysis of flow velocities determined by doppler identifies:Degree of stenosisPlaque morphology and surface

characteristics*** Plaque surface characteristics may be more significant than degree of stenosis in

determining risk for cerebral vascular events.

Duplex imaging is advocated as sole means ofevaluating carotid disease by many:

• 7-10% error rate in “best of hands.”

• Positive predictive value > 90% identifying 70-99% internal carotid stenosis.

• No evaluation of distal ICA or intracranial • stenosis.

Carotid Duplex Imaging

Unstable Plaque Surfaces

Less than 50%• Peak systolic: <130 cm/sec• ICA:CCA ratio: < 1.8

50% to 69%• Peak systolic: 130 to 210 cm/sec• ICA:CCA ratio: 1.8 to 3.1

70% to 99%• Peak systolic: > 210 cm/sec• ICA:CCA ratio: > 3.1

Duplex Criteria for Native Carotid Lesions

*** Other high risk ultrasound findings include : ulcers, intraplaque hemorrhage, intraluminal thrombus or debris, intimal flaps or dissections.

Ulcerative Plaque Characteristics

Ulcerative Plaque By Duplex Ultrasound

Intraplaque Hemorrhage:

High risk for fibrous cap rupture,

embolism and neurological symptoms.

Complex Irregular Plaque By Duplex Ultrasound

Contrast Angiography:

• “Gold Standard” for anatomical detail

• Provides information about tandem atherosclerotic disease, plaque morphology, and collateral circulation.

• Invasive procedure

• 0.1-1% stroke rate with angiogram alone during NASCET and ACAS trials.

MR Angiography:

Non invasive

MRI Contrast contraindicated with impaired renal function

Does not provide bony anatomical detail useful in surgical planning

No pacemakers, etc

CT Angiogram:

High resolution anatomical detail with good bone and calcium definition.

Iodinated contrast load can be similar to conventional angiography.

3-D imaging requires post scanning production to create images.

Estimating Stenosis

Endarterectomy Trials

659 Pts, 50 centers: TIA, Afx, Non-Disabling CVA within 6 months:

Best Med vs CEA + best Med

659 Pts, 50 centers: TIA, Afx, Non-Disabling CVA within 6 months:

Best Med vs CEA + best Med

26%

13%22%

15%19%16%

3%9%

70-99%: IpsiCVA @ 2 yr

(p<0.001)

70-99%:Maj/Fatal

CVA @ 2 yr(p<0.001)

50-69%: IpsiCVA @ 5 yrs

(p<0.045)

30-49%: IpsiCVA @ 5 yrs

(NS)

Med CEA

Perioperative stroke/death rate = 5.8%

Symptomatic Carotid Stenosis: NASCET Trial

1662 Pts, 39 centers: Asymptomatic Carotid Stenosis > 60%

Best Med vs. Best Med plus CEA.

Outcomes: ipsilateral CVA or any CVA or death

1662 Pts, 39 centers: Asymptomatic Carotid Stenosis > 60%

Best Med vs. Best Med plus CEA.

Outcomes: ipsilateral CVA or any CVA or death

11%

3%5%

Ipsi CVA @ 5 yrs Periop Stroke/Death

Med CEA

• Over half periop events related to angiogram• Conclusion: CEA for ASX stenosis > 60% justified with

careful technique and patient selection.

Asymptomatic Carotid Stenosis: ACAS Trial

Long-term Risk of Stroke

Operative Risk and Stroke Prevention

CREST Study DesignCREST Study Design

• Prospective, multicenter, randomized, controlled trial with blinded endpoint adjudication.

• Comparing CEA and CAS in participants with symptomatic and asymptomatic stenosis

• 108 US and 9 Canadian sites

• Team included neurologist, interventionalist, surgeon, and research coordinator at each center.

• NEJM May, 2010.

  CAS(n=1262)

CEA(n=1240)

Age 69 69Female - % 36 34

Asymptomatic - % 47 47

Hypertension - % 86 86Diabetes - % 30 30Dyslipidemia - % 82 85

Current smoker - % 26 26

CREST: Patient Characteristics

• Peri-procedural (a composite of):

any Clinical Stroke

Myocardial infarction

Death

• Post-procedural

Ipsilateral stroke up to 4 years

CREST Primary EndpointCREST Primary Endpoint

• An acute neurological ischemic event of at

least 24 hours duration with focal signs and

symptoms.

• Adjudicated by at least two neurologists

blinded to treatment

CREST: StrokeCREST: Stroke

• Combination:

• Elevation of cardiac enzymes (CK-MB or troponin) to a value 2 or more times the individual clinical center's laboratory upper limit of normal. Plus

• Chest pain or equivalent symptoms consistent with myocardial ischemia, or, ECG evidence of ischemia including new ST segment depression or elevation > 1mm in 2 or more contiguous leads

• Not enzyme-only

• Adjudicated by two cardiologists blinded to treatment

CREST: Myocardial Infarction

CREST: Myocardial Infarction

Primary Endpoint: peri-procedural components

(any death, stroke, or MI within peri-procedural period)

CAS vs. CEA Hazard Ratio, 95% CI P-Value

5.2 vs. 4.5% HR = 1.18; 95% CI: 0.82-1.68 0.38

Peri-procedural Stroke and MI

  CAS vs. CEA Hazard Ratio 95% CIP-Value

Stroke 4.1 vs. 2.3% HR = 1.79; 95% CI: 1.14-2.82 0.01

MI 1.1 vs. 2.3% HR = 0.50; 95% CI: 0.26-0.94 0.03

Peri-procedural Stroke

  CAS vs. CEA Hazard Ratio 95% CIP-Value

All Stroke 4.1 vs. 2.3% HR = 1.79; 95% CI: 1.14-2.82 0.01

Major Stroke 0.9 vs. 0.6% HR = 1.35; 95% CI: 0.54-3.36 0.52

“The quality of life analysis among survivors at one year in our trial indicate that stroke had a greater adverse effect on a broad range of health-status domains than did myocardial infarction”

Ipsilateral Stroke after Peri-procedural Period ≤ 4 years

CAS vs. CEA Hazard Ratio, 95% CIP-Value

2.0 vs. 2.4% HR = 0.94; 95% CI: 0.50-1.76 0.85

CREST ConclusionsCREST Conclusions• CEA and CAS have similar net outcomes

though the individual risks vary, lower stroke with CEA and lower MI with CAS.

Hazard Ratio (log scale)

0.01 0.1 1 10

Cranial Nerve Palsy

Minor Non-Ispi Stroke

Minor Ipsi Stroke

Major Non-Ipsi Stroke

Major Ipsi Stroke

Any Stroke

Any Death

MI Endpoint

Stroke + Death Endpoint

Stroke Endpoint

Primary Endpoint

CAS Superior | CEA Superior

CREST and Octagenarians• The risk of stroke with CAS was 13 x higher in those past the age of 80.

• Thought to be due to plaque within the aortic arch that is disrupted with catheter / wire manipulation.

• CAS not recommended in those >80 except in the most extenuating of circumstances. (High lesions, radiation to neck, tracheostomy, high cardiac risk, etc)

Center for Medicare/Medicaid Services (CMS) criteria for Carotid Artery Stent (CAS) reimbursement 2011:

1. Symptomatic patient2. >70% stenosis3. “High Risk” patient

All three criteria must be met, and a distal embolic protection device must be used.

At present, CMS has no plans to expand CAS coverage following the results of the CREST trial.

Surgical Management:Patient Selection

Patient Selection

• Less than 50% carotid stenosis regardless of plaque morphology

• 50-69% stenoses with low risk or stable plaques• Treatment centers on preventing platelet

aggregation and embolization• Recommended drugs:

• Aspirin 160-325mg./day• Clopidogeral (Plavix) 75 mg/day• Ticlopidine (Ticlid) 250mg. b.i.d.• Aggressive lipid control

MEDICAL MANAGEMENT

FOLLOW-UP GUIDELINES

Nonsurgical patients with significant disease:

• Duplex imaging every 6-12 months depending upon plaque morphology and rate of stenosis progression

• Immediate re-evaluation if new symptoms develop

Carotid Endarterectomy: Indications

Carotid Endarterectomy: Indications

Symptomatic Disease

•Carotid Stenosis > 70% stenosis

•Acceptable > 50% stenosis

•Unacceptable if stroke/death > 5%

Asymptomati

c Disease

•Carotid Stenosis > 60% stenosis

•Unacceptable if stroke/death > 3%

* Look for other causes of stroke – TEE, Holter, Hypercoagulable work-up

So why are you watching my asymptomatic patient with a 70-

99% carotid stenosis by Ultrasound?

So why are you watching my asymptomatic patient with a 70-

99% carotid stenosis by Ultrasound?

• ACAS and other trials would suggest a surgeon has to do ~ 17 uncomplicated CEA’s to prevent one stroke.

• A 70-99% US stenosis may not be equivalent to a 60% or greater angiographic stenosis (which was used in the trials). I agree, very confusing.

• Several studies suggest, elevated EDV >100 or 125 cm/s and spectral broadening confer hemodynamic significance.

• The individual patients comorbidities, age, and ultrasound plaque characteristics are all taken into account.

Carotid Endarterectomy:

Technique

Neck Incision

Carotid Endarterectomy

Endarterectomy

Ouriel and Rutherford

Carotid EndarterectomyCarotid Endarterectomy

Carotid EndarterectomyCarotid Endarterectomy

Carotid Endarterectomy: Shunt insertion

Carotid Endarterectomy: Plaque Removal

Carotid Endarterectomy: Plaque Removal

Carotid Endarterectomy: Plaque Removal

Carotid Endarterectomy: Vein PatchCarotid Endarterectomy: Vein Patch

Carotid Endarterectomy:

Complications

Asymptomatic Lesions 3%

TIA 5%

Ischemic Stroke 7%

Recurrent disease 10%

30 Day Mortality 2%

Combined Stroke and Death Rate

Combined Stroke and Death Rate

*** Leading cause of death is myocardial infarction ***

Postoperative carotid artery thrombosis Cerebral ischemia during carotid clamping

Intraoperative embolization

Reperfusion edema

Intra-cerebral hemorrhage

Causes of Perioperative Stroke

Causes of Perioperative Stroke

Recurrent laryngeal nerve 1.5-15%

Hypoglossal nerve 4-6%

Marginal mandibular nerve 1-3%

Superior laryngeal nerve 1-3%

Spinal accessory nerve 0.5-1%

Complications: Nerve Injury

*** most are transient ***

Recurrent laryngeal nerve Hypoglossal nerve

Cranial Nerve Injury

Surgical Management:

Follow-up Guidelines

•Incidence 5-22% (1.5 to 4.5% annual)

•Pathology •< 2 mos :

residual atherosclerosis

•< 24 mos:neointimal hyperplasia

•> 36 mos :recurrent atherosclerosis

Recurrent Stenosis

•Diabetes mellitus

•Hyperlipidemia

•Hypertension •Smoking •Young patient•Women

Risk Factors

Recurrent StenosisRecurrent Stenosis

Summary Recommendations

SURGICAL MANAGEMENT

Asymptomatic• 80 to 99% in surgically fit patient• Consider in >60% range if unfavorable

plaque.Symptomatic• 50% or higher • Implies ideal surgical results and optimum

surgical risk.

Recurrent Disease • If symptomatic• Stent v. Surgical Reconstruction

Patient Selection

SummarySummary• Carotid artery occlusive disease is the

most readily treatable lesion leading to stroke.

• In appropriately selected patients, Carotid endarterectomy remains a safe and effective treatment of cervical carotid occlusive disease.