Carotid Artery Occlusive Disease

Question 1

Cerebrovascular disease constitutes the ____ leading cause of death
in the U.S.

Answer 1

3rd

Question 2

Causes of Atherosclerosis

Answer 2

Genetics
Tobacco Abuse
Hypertension
Diabetes
Hyperlipidemia
^ homocysteine levels
Diet and obesity
Female
Job/environment

Question 3

Diabetes and CAOD

Answer 3

• Increased lipoproteins
• Inhibits basement membrane function
• Platelet aggregation
• Cytokine-enhanced smooth muscle cell proliferation
• Enhancement of thrombogenic factors II, V, and X

Question 4

Tobacco Abuse and CAOD

Answer 4

• Carbon monoxide → arterial wall injury, increased plasma flux, entry of LDL,
intimal hyperplasia
• Increased platelet reactivity
• Lowers HDL levels
• Peripheral vasoconstriction

Question 5

Risk Factor Reduction

Answer 5

 Platelet Inhibitor
 Smoking cessation
 Control hypertension
 Control diabetes
 Decrease hyperlipidemia, LDL level, and triglycerides
 Diet
Aerobic exercise
 Multivitamin
 Vitamin E and Vitamin C—antioxidants, increase vascular elasticity
 B-complex vitamins with B6, B12, and folic acid—decrease
homocysteine levels
 Omega 3 fish oil

Question 6

Medical Management:

Coated Aspirin

Answer 6

Inhibits cyclooxygenase activity which blocks prostaglandin metabolism and synthesis of thromboxane A2—stimulator of platelet aggregation
• Mainly COX 1 (platelets), COX2 (inflammatory cells) 50:1

Question 7

Medical Management:

Ticlopidine (Ticlid)

Answer 7

Inhibits adenosine diphosphate (ADP), which plays a central role in platelet aggregation and activation
• Complications: rash, diarrhea, life-threatening neutropenia (can be fatal)

Question 8

Medical Management:

Persantine

Answer 8

Not shown to be more affective than aspirin alone or in combination

Question 9

Medical Management:

Clopidigrel

Answer 9

• Blocks ADP receptor P2Y12 , an extra carboxymethyl side group
• 6 times more potent than Ticlid with fewer side effects
• CAPRIE trial (Clopidogrel vs Aspirin in Patients at Risk of Ischemic Events)
• 8.7% risk reduction in vascular death, ischemic stroke, and myocardial infarction versus aspirin

Question 10

Asymptomatic Patient

Answer 10

NASCET study, European Carotid Surgery trial, CASANOVA study
• Surgical Intervention—superior results to medical management when stenosis is 70% or greater
• Stroke rates at 1, 3, and 5 years were 23%, 37%, and 45%, respectively in the
asymptomatic patient

Question 11

Symptomatic Patient

TIA, RIND

Answer 11

• Symptomatic patient with:
70% stenosis— 35% risk of stroke in 1 year
80% stenosis— 46% risk of stroke in 1 year, 62% risk in 2 years
90% stenosis— 75% risk of stroke within 1 year

Question 12

Transient Ischemic Attack

Answer 12

– Principal cause is a brief disruption in perfusion
– Initial symptom of carotid disease and precursor of an impending stroke
– Signs and symptoms typically resolve within hours
– Focal neurological deficit lasting less than 24 hours
– Complete recovery

Question 13

Symptomatic Patient

CVA/Stroke

Answer 13

• High likelihood of a 2nd stroke with worsening deficits
• Periumbra region, “scar down period” to prevent an ischemic infarction to worsen/extend by way of a hemorrhagic infarction during reperfusion

Question 14

Stroke

Answer 14

Acute neurological deficit of
vascular origin persisting longer
than 24 hours

Question 15

Major Stroke

Answer 15

defined as neurological deficit which lasts longer than seven days and increases the NIH stroke scale number by >4

Question 16

Minor Stroke

Answer 16

defined as a neurological deficit lasting >24

hours and increases the NIH stroke scale by <3

Question 17

Symptomatic Patient

Stroke in Evolution

Answer 17

“stuttering stroke”

“catch 22” - damned if you do, damned if you don’t

Question 18

Diagnosis of Carotid Artery Disease

Answer 18

Many imaging tools are
used to diagnosis disease
• Choose optimal method
• Imaging tools used with
good results
• Angiography
• Duplex ultrasonography

CTA
MRA

Question 19

Doppler

Answer 19

Indications: carotid bruits (cardiac source, stenosis, tortuosity), symptomatic, continued monitoring and follow-up

Duplex Scanning: non-invasive, can characterize % stenosis/consistency/ulcerations, 92-95% accurate

Question 20

Contrast Studies

Answer 20

 Advantage
• To confirm doppler findings
• “Roadmap” for surgery
• Visualization of aortic arch, extracranial vessels (subclavian and vertebral arteries), and intracranial vessels
 Carotid cerebral angiography
• Still the “gold standard”
• Invasive
• Most institutions forgo this, provided that non-invasive preoperative testing is of diagnostic quality and correlates with the patients clinical presentation
 Cat scan angiography
 MRA with gadolinium

Question 21

Surgery:

Carotid Endarterectomy

Answer 21

1. Shunt
2. Patch graft angioplasty
3. Anti-platelet drugs
4. Cranial nerve injury
5. Stroke, mortality
   • The combined perioperative risk of death and stroke was 3% to 3.5% in asymptomatic patients, compared with 5.18% for symptomatic patients
6. Post-operative follow-up
   • Dopplers—6wks, 6months, 1 year, then annually

Question 22

Surgery:

Carotid Stenting

Answer 22

1. Being used with increasing frequency in many centers worldwide
   Still very controversial for when it should be used
   Initially, significantly higher stroke morbidity and mortality rate
2. Carotid Revascularization Endarterectomy vs. Stent Trial (CREST)
   • Cerebral anti-embolism device/cerebral protection
   • Ongoing trial for several more years funded by NIH and guidant
   • Initial study—13% stroke and death rate in patients older than 80yrs. Trial has stopped enrolling octogenarians.
   • 30-day morbidity and mortality rate 5.5% for symptomatic patients, 2.8% for asymptomatic patients. These results
   compare very well with surgical series.
   • Average cost for carotid endarterectomy $21,670, whereas carotid angioplasty with stenting costs $36,140

Question 23

Possible indications for carotid stenting

Answer 23

• Class III or IV congestive heart failure
• Open heart surgery needed within 6 wks
• Recent myocardial infarction (>24hr and <4wks)
• Unstable angina (Class III or IV)
• Severe pulmonary disease
• Contralateral carotid occlusion
• Contralateral laryngeal nerve palsy
• Radiation therapy to neck
• Previous CEA with recurrent stenosis
• High cervical ICA lesions or CCA lesions below the clavicle
• Severe tandem lesions

Question 24

Treatment of Carotid Artery Disease

Answer 24

Carotid stenting
• Less invasive, percutaneous
• Developed for patients at high risk for surgical intervention
• Safety of procedure has improved with advent of embolic protection
devices

Question 25

Preoperative Evaluation

Answer 25

• Cardiac clearance—stress testing
• Pulmonary function testing
• Beta-blocker protocol