Carotid Artery disease

Question 1

Majority of strokes are from? Prevalence of CAS?

Answer 1

• Majority of strokes are ischemic (90%) – strokes due to Arteriosclerotic disease of the Extra - cranial arteries , not intra-cranial disease
• Prevalence of asymptomatic CAS (Carotid Artery Stenosis) of at least 50% is 4.2% – Increases with age (>70 y/o) – • 7% of women, • 12% of men

Question 2

Effects of stroke? Disability?

Answer 2

• Stroke is the Fourth Leading cause of Death • 800,000 Americans will suffer a stroke this year – 600,000 for the first time – 160,000 will die • Every 45 seconds, someone suffers a stroke in the United States –Every 3 minutes, someone dies from a stroke in the U.S
• Leading cause of Disability • Disability from stroke must be considered from the standpoint of the: – Physically disabled patient – Psychological effect on the patient – Socio-economical burden on the patient/patient’s family – Socio-economical burden on society • Strokes cost $56.8 billion annually in health care costs and lost productivity

Question 3

First branch of the internal carotid artery?

Answer 3

First branch is the Ophthalmic Artery

Question 4

What is the Carotid bulb? Atherosclerosis occur most where?

Answer 4

• Carotid Bulb – bifurcation of Internal and External Carotid Arteries
• Atherosclerosis accounts for 90% of Cerebral-Vascular Dysfunction
• Atherosclerotic lesions most commonly occur at Bifurcations of Arterial Branches !!

Question 5

Plaques in the carotid artery may?

Answer 5

• Plaque may Hemorrhage within itself
• Hemorrhage may precipitate Extension of the lesion  Occlusion
• C.V.A.
• Plaque may enlarge • Central portion softens • Plaque Ruptures and Embolize • T.I.A. or C.V.A.
• Open cavity may remain as a Central Ulcer • Nidus for Platelet Aggregation • Nidus for Thrombosis • Platelet aggregates or Thrombus may then Embolize

Question 6

Neurological symptoms from carotid plaques?

Answer 6

• Remaining 10% of pathology:

– Carotid • Fibromuscular dysplasia • Arterial Kinking • Extrinsic Compression • Traumatic Occlusion • Intimal Dissection – Inflammatory Angiopathies – Temporal arteritis – Migraines

• Embolization may also be of Cardiac origin or from the Ascending Aorta

Question 7

What is a Transient ischemic attack?

Answer 7

• Episode of Neurologic Dysfunction that last less than 24 hours – Duration Usually Minutes – Returns to Pre-attack Status

• Lateralizing Symptoms
• Majority caused by Emboli via Patent I.C.A.
• May occur with an Occluded vessel, via collaterals, opposite I.C.A. or Vertebral artery

• Carotid stenosis + TIA –12% risk of stroke the first year –35% 5 year risk

Question 8

What is amaurosis fugax?

Answer 8

• A Lateralizing symptom
• Visual Disturbances in the Ipsilateral Eye
• Temporary Loss of Vision
• “Like a window shade coming over my eye”
• Associated with an increased risk of stroke

Question 9

Diagnosis of CAD?

Answer 9

• History • Physical exam • Non-invasive evaluation - Duplex Ultrasound • Arteriography

Question 10

Risk factors for CAD?

Answer 10

Cerebral vascular Atherosclerosis is a Localized Manifestation of a Systemic Process: – Diet and Activity – Hypertension – Diabetes – Smoking – Family History – etc.
• Associated factors –Coronary Artery Disease (CAD) –Peripheral Arterial Disease (PAD) • Advancing Age –Risk of stroke in 70’s is 8 times greater than in 50’s

Question 11

What questions should you ask with CAD patients?

Answer 11

• Aura? • Motor activity, Weakness? - TIA • Amaurosis Fugax • Headache – Migraine • Question family and friends • Family history • Hypertension, Diabetes, etc.

Question 12

Symptoms of CAD?

Answer 12

• Exact manifestation of neurological dysfunction depends on the distribution of the involved artery within the brain
• Occlusion of Artery – Embolic • Size & Nature of Emboli • Final location of embolic fragment – Thrombosis
• Dysphasia –Usually Expressive
• Visual loss (ipsilateral)
• Motor Weakness (contralateral)
• Sensory Loss (contralateral)
• Seizures - rare
• Varies from minor episodes of Neurological dysfunction to major cerebral infarction and stroke

Question 13

Physical exam of CAD?

Answer 13

• General Appearance • Bilateral Upper Extremity Blood Pressure • Peripheral Pulses • Heart, Lung, Abdomen, etc.

Question 14

Carotid bruits?

Answer 14

• Turbulent blood flow
• Anterior & Medial to S.C.M. muscle at angle of jaw
• May be radiation of a Cardiac Murmur – Proximal to bifurcation
• Have patient take several deep breaths then listen
• Up to 40% have no bruit

Question 15

Carotid pluse with CAD? Optho exam?

Answer 15

• Subclavian Bruits
• Carotid Pulse – Quality and Force – Do not massage artery!!
• Ophthalmologic Exam – Yellow Refractile Bodies • Cholesterol Emboli • Hollenhorst Plaque

• Neurologic Exam – Deficits

Question 16

What are the non-invasive diagnostic tests for CAD?

Answer 16

– Duplex Ultrasound – C.T. Angiography – MRA – Magnetic Resonance Angiography

Question 17

Explain Duplex scanning for CAD? Limitations?

Answer 17

• Combines real time Ultrasound & Pulse Doppler
• Estimates degree and extent of Stenosis
• Morphology of the plaque – Ulceration – Hemorrhage • Excellent for Follow-up
• Safe and Inexpensive
• Reproducible
• Requires skilled technologist

• Limitations –“Thick neck” –High Carotid bifurcation –Deep vessels • Complication - None known • Treatment is commonly based on Duplex Scanning (surgical vs. conservative)

Question 18

CTA use in CAD?

Answer 18

• Computer Assisted Tomography – Angiogram • Commonly available • Requires contrast which has its risks –Renal toxicity –Allergic • Limited benefit if artery is heavily calcified

Question 19

MRA use in CAD?

Answer 19

• MRA – Magnetic Resonance Angiography • Increasingly available • Requires contrast which has its risks –Renal & Allergies • May not be used in patients with certain metallic implants • Claustrophobia is a problem

Question 20

Angiography for CAD?

Answer 20

• Digital Subtractive Angiography (D.S.A.) – Less contrast (dye) – Computer enhanced – Risks • Strokes 0.2% • Death 0.05%

Question 21

Therapy for CAD?

Answer 21

• Conservative –Observation with Serial Duplex exams
• Medical management
• Surgical management –Carotid Endarterectomy (C.E.A.) –Balloon Angioplasty / Stent

Question 22

Medical therapy has what two components?

Answer 22

Anti-Platelet: • Aspirin • Aggrenox® – Dipyridamole & Aspirin • Clopidogrel Bisulfate (Plavix®) • Risks –Platelet dysfunction –GI – Upset, Bleeding –Bleeding - Trauma, Cerebral, etc

Anti-Coagulation: • Heparin (unfractionated) -Acute therapy • Low Molecular Weight Heparin (LMWH) –Enoxaparin –Daltaparin • Warfarin (Coumadin®) -Long term therapy

Question 23

Surgery for CAD?

Answer 23

• Because - The higher the degree of stenosis, the more likely it is that a patient will suffer an ischemic neurological event. • Carotid Endarterectomy(C.E.A.) is accepted as the preferred form of therapy for Stroke Prevention in certain categories of patients. • Percutaneous intervention – angioplasty/stent – Has specific indications – Has not replaced CEA

All four studies favored Carotid Endarterectomy • NASCET and ECST suggested > 70% stenosis should be operated • BUT – “the jury is still out!”

CEA is • Most common procedure performed to prevent stroke • 140,000 CEA in the U.S. annually

Question 24

When to offer surgery?

Answer 24

• Symptomatic vs. Asymptomatic • “Fear of Stroke” • Degree of stenosis: 65% +/• Nature of Plaque

Question 25

Perio-op mortality should be what for both asymptomatic and symptomatic patients?

Answer 25

• Peri-operative morbidity/mortality should be: – <3% asymptomatic patients – <6% symptomatic patients
• 5% - 10% post-endarterectomy re-stenosis rate

Question 26

Surgery risks for CAD?

Answer 26

• Bleeding
• Infection
• Myocardial Infarction
• Respiratory Insufficiency
• Renal Failure
• DEATH (0.4%)
• Neurologic Deficits – Dysphagia – Hoarseness of the voice – Deviation of the tongue – Numbness, Paresthesia, Weakness of Face or Neck • C.V.A. (<4.0%)

• Progression/Recurrence of Disease (5% - 10%)

Question 27

Percutaneous angioplasty?

Answer 27

• Not approved for routine treatment –C.E.A. is still treatment of choice
• For patients at High Risk for surgery –“Hostile Neck” • Radiation
• Post radical neck surgery • Tracheostomy –Recurrent Disease

Question 28

What is vertebral basilar syndrome?

Answer 28

• Non-lateralizing TIA –Brainstem - Posterior Circulation –Dizziness, Vertigo, Ataxia or Syncope
• May be precipitated by Postural changes
• Considered to be Flow Related, not embolic

Question 29

What is vertebral steal syndrome?

Answer 29

• “Subclavian Steal Syndrome”
• Posterior Circulation ischemia
• Blood is diverted away from the Vertebral-basilarsystem as a result of Retrograde flow down the Ipsilateral vertebral artery
• Symptoms may increase with exercising the upper extremity

Question 30

What are the posterior circulation symptoms?

Answer 30

• Vertebral-basilar circulation
• Brainstem

• Less clear cut symptoms • Ataxia –Vertigo –Syncope –Drop attacks