Carotid Artery disease Flashcards
Majority of strokes are from? Prevalence of CAS?
- 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
Effects of stroke? Disability?
- 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
First branch of the internal carotid artery?
First branch is the Ophthalmic Artery
What is the Carotid bulb? Atherosclerosis occur most where?
- 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 !!
Plaques in the carotid artery may?
- 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
Neurological symptoms from carotid plaques?
• 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
What is a Transient ischemic attack?
• 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
What is amaurosis fugax?
- 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
Diagnosis of CAD?
• History • Physical exam • Non-invasive evaluation - Duplex Ultrasound • Arteriography
Risk factors for CAD?
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
What questions should you ask with CAD patients?
• Aura? • Motor activity, Weakness? - TIA • Amaurosis Fugax • Headache – Migraine • Question family and friends • Family history • Hypertension, Diabetes, etc.
Symptoms of CAD?
- 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
Physical exam of CAD?
• General Appearance • Bilateral Upper Extremity Blood Pressure • Peripheral Pulses • Heart, Lung, Abdomen, etc.
Carotid bruits?
- 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
Carotid pluse with CAD? Optho exam?
- Subclavian Bruits
- Carotid Pulse – Quality and Force – Do not massage artery!!
- Ophthalmologic Exam – Yellow Refractile Bodies • Cholesterol Emboli • Hollenhorst Plaque
• Neurologic Exam – Deficits
What are the non-invasive diagnostic tests for CAD?
– Duplex Ultrasound – C.T. Angiography – MRA – Magnetic Resonance Angiography
Explain Duplex scanning for CAD? Limitations?
- 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)
CTA use in CAD?
• Computer Assisted Tomography – Angiogram • Commonly available • Requires contrast which has its risks –Renal toxicity –Allergic • Limited benefit if artery is heavily calcified
MRA use in CAD?
• 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
Angiography for CAD?
• Digital Subtractive Angiography (D.S.A.) – Less contrast (dye) – Computer enhanced – Risks • Strokes 0.2% • Death 0.05%
Therapy for CAD?
- Conservative –Observation with Serial Duplex exams
- Medical management
- Surgical management –Carotid Endarterectomy (C.E.A.) –Balloon Angioplasty / Stent
Medical therapy has what two components?
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
Surgery for CAD?
• 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
When to offer surgery?
• Symptomatic vs. Asymptomatic • “Fear of Stroke” • Degree of stenosis: 65% +/• Nature of Plaque
Perio-op mortality should be what for both asymptomatic and symptomatic patients?
- Peri-operative morbidity/mortality should be: – <3% asymptomatic patients – <6% symptomatic patients
- 5% - 10% post-endarterectomy re-stenosis rate
Surgery risks for CAD?
- 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%)
Percutaneous angioplasty?
- 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
What is vertebral basilar syndrome?
- Non-lateralizing TIA –Brainstem - Posterior Circulation –Dizziness, Vertigo, Ataxia or Syncope
- May be precipitated by Postural changes
- Considered to be Flow Related, not embolic
What is vertebral steal syndrome?
- “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
What are the posterior circulation symptoms?
- Vertebral-basilar circulation
- Brainstem
• Less clear cut symptoms • Ataxia –Vertigo –Syncope –Drop attacks
