Peripheral arterial disease-1 carotid

Peripheral arterial Peripheral arterial disease-1disease-1

carotidcarotidSeyed Ebrahim Kassaian, MDSeyed Ebrahim Kassaian, MD

Tehran Heart CenterTehran Heart CenterTehran University of Medical Tehran University of Medical

SciencesSciences

BackgroundBackground

StrokeStroke is the third leading cause of is the third leading cause of death (164,000 deaths/year) in the death (164,000 deaths/year) in the U.S., behind heart disease and U.S., behind heart disease and cancercancer

StrokeStroke is the leading cause of serious is the leading cause of serious long-term disabilitylong-term disability

AtherosclerosisAtherosclerosis accounts for up to accounts for up to one-third of all strokes.one-third of all strokes.

Approximately 50% of strokes occur Approximately 50% of strokes occur in the distribution of the carotid in the distribution of the carotid arteriesarteries

extracranial carotid disease is more extracranial carotid disease is more frequent in Caucasians, frequent in Caucasians,

intracranial disease is more frequent intracranial disease is more frequent in African Americans, Hispanics, and in African Americans, Hispanics, and AsiansAsians

BackgroundBackground

Carotid occlusive disease amenable to Carotid occlusive disease amenable to revascularization accounts for revascularization accounts for 5% to 12%5% to 12% of new strokesof new strokes

The pattern of progression of carotid The pattern of progression of carotid stenosis is stenosis is unpredictableunpredictable, and disease may , and disease may progress swiftly or slowly, or remain stable progress swiftly or slowly, or remain stable for many yearsfor many years

Nearly 80% of strokes due to embolization Nearly 80% of strokes due to embolization in the carotid distribution may occur in the carotid distribution may occur without warning, emphasizing the need for without warning, emphasizing the need for careful patient follow-upcareful patient follow-up

Neurovascular Anatomy and Neurovascular Anatomy and PhysiologyPhysiology

Great Vessel AnatomyGreat Vessel Anatomy

Anatomical Variants andAnatomical Variants andAnomalies in Cerebral AngiographyAnomalies in Cerebral Angiography

Extracranial and Intracranial Extracranial and Intracranial CirculationCirculation

normal vascular physiologynormal vascular physiology

Compression or stretching of the carotid sinus can cause a Compression or stretching of the carotid sinus can cause a vasovagalvasovagal (hypotension and bradycardia) or (hypotension and bradycardia) or vasodepressorvasodepressor (hypotension without (hypotension without bradycardia) response and systemic hypotension.bradycardia) response and systemic hypotension.

These responses are mediated via stimulation of the carotid sinus nerve (a These responses are mediated via stimulation of the carotid sinus nerve (a branch of the branch of the glossopharyngeal nerveglossopharyngeal nerve) in the carotid baroreceptor, and ) in the carotid baroreceptor, and vagus nerve activation leading to inhibition of sympathetic tone.vagus nerve activation leading to inhibition of sympathetic tone.

The sensitivity of the carotid baroreceptors is variable and may be The sensitivity of the carotid baroreceptors is variable and may be affected by affected by medications medications (e.g., vasodilators and beta-blockers might (e.g., vasodilators and beta-blockers might increase sensitivity), the presence of increase sensitivity), the presence of calcified plaquecalcified plaque in the carotid bulb in the carotid bulb (increased sensitivity), or (increased sensitivity), or prior CEAprior CEA (decreased sensitivity). (decreased sensitivity).

Pathology and PathophysiologyPathology and Pathophysiology

AtherosclerosisAtherosclerosis usually unifocal, and 90% of lesions are located usually unifocal, and 90% of lesions are located

within 2cm of the ICA originwithin 2cm of the ICA origin The degree of carotid stenosis is associated with The degree of carotid stenosis is associated with

stroke risk. stroke risk. Carotid atherosclerosis can produce retinal and Carotid atherosclerosis can produce retinal and

cerebral symptoms by 1 of 2 major mechanisms:cerebral symptoms by 1 of 2 major mechanisms: progressive carotid progressive carotid stenosisstenosis leading to in-situ leading to in-situ

occlusion and hypoperfusion (less common), occlusion and hypoperfusion (less common), intracranial arterial occlusion resulting from intracranial arterial occlusion resulting from

embolizationembolization (more common)(more common)

Pathology and PathophysiologyPathology and Pathophysiology

Patients presenting with carotid Patients presenting with carotid distribution cerebral ischemia should distribution cerebral ischemia should be thoroughly evaluated for treatable be thoroughly evaluated for treatable causes, including sources of emboli causes, including sources of emboli from the carotid arteries, heart, and from the carotid arteries, heart, and aortic arch.aortic arch.

Natural History and Risk Natural History and Risk StratificationStratification

A A carotid bruitcarotid bruit is identified in 4% to 5% of is identified in 4% to 5% of patients age 45 to 80 years, and should be heard patients age 45 to 80 years, and should be heard in the majority of patients with carotid stenosis in the majority of patients with carotid stenosis greater than or equal to 75%greater than or equal to 75%

cervical bruits are cervical bruits are neither specific nor sensitiveneither specific nor sensitive for identifying severe carotid stenosisfor identifying severe carotid stenosis

The risk of progression of carotid stenosis is The risk of progression of carotid stenosis is 9.3% per year; risk factors for progression 9.3% per year; risk factors for progression include :include :

1.1. ipsilateral or contralateral ICA stenosisipsilateral or contralateral ICA stenosis greater greater than 50%,than 50%,

2.2. ipsilateral ECA stenosisipsilateral ECA stenosis greater than 50%, greater than 50%, 3.3. systolic blood pressuresystolic blood pressure greater than 160 mm Hg greater than 160 mm Hg


The annual stroke risk in patients with The annual stroke risk in patients with carotid stenosis is most carotid stenosis is most dependent on dependent on symptom status and stenosis symptom status and stenosis severityseverity, but is also influenced by the , but is also influenced by the presence of presence of

silent cerebral infarction, silent cerebral infarction, contralateral disease, contralateral disease, extent of collaterals, extent of collaterals, the presence of atheroscleroticrisk factors, the presence of atheroscleroticrisk factors,

plaque morphologyplaque morphology


The stroke risk is much higher in The stroke risk is much higher in symptomaticsymptomatic patients than in asymptomatic patients, and the patients than in asymptomatic patients, and the risk is highest risk is highest immediately afterimmediately after the initial the initial ischemic eventischemic event

Symptomatic Patients with carotid stenosis 70% Symptomatic Patients with carotid stenosis 70% to 99% had a 2-year ipsilateral stroke risk of to 99% had a 2-year ipsilateral stroke risk of 26%.26%.

In asymptomatic patients, the annual stroke risk In asymptomatic patients, the annual stroke risk is much lower than in symptomatic patients, and is much lower than in symptomatic patients, and is less than 1% for carotid stenoses less than 60% is less than 1% for carotid stenoses less than 60% and 1% to 2.4% for carotid stenoses greater than and 1% to 2.4% for carotid stenoses greater than 60%60%


Patients referred for Patients referred for CABGCABG have a have a particularly high incidence of particularly high incidence of asymptomatic carotid stenosis with a asymptomatic carotid stenosis with a prevalence of 17% to 22% for carotid prevalence of 17% to 22% for carotid stenosis greater than 50% and 6% to 12% stenosis greater than 50% and 6% to 12% for carotid stenosis greater than 80%for carotid stenosis greater than 80%

The risk of The risk of perioperative strokeperioperative stroke after CABG after CABG is 2% for carotid stenosis less than 50%, is 2% for carotid stenosis less than 50%, 10% for carotid stenosis 50% to 80%, and 10% for carotid stenosis 50% to 80%, and as high as 19% for carotid stenosis greater as high as 19% for carotid stenosis greater than 80%than 80%


silent cerebral infarctionsilent cerebral infarction in patients with in patients with asymptomatic carotid stenosis = 15% to asymptomatic carotid stenosis = 15% to 20% ,and has a higher risk of subsequent stroke20% ,and has a higher risk of subsequent stroke

In NASCET patients with carotid stenosis 70% to In NASCET patients with carotid stenosis 70% to 99%, the presence of contralateral carotid 99%, the presence of contralateral carotid occlusion increased stroke risk by more than 2-occlusion increased stroke risk by more than 2-fold, whereas the fold, whereas the presence of collateralspresence of collaterals decreased the stroke risk by more than 2-fold . decreased the stroke risk by more than 2-fold .

Stroke risk in symptomatic patients may also be Stroke risk in symptomatic patients may also be influenced by influenced by plaque morphologyplaque morphology, including the , including the presence of presence of hypoechoichypoechoic or or echolucentecholucent plaque plaque and plaque ulceration irrespective of the degree and plaque ulceration irrespective of the degree of stenosis.of stenosis.

Clinical Syndromes AssociatedClinical Syndromes AssociatedWith Extracranial Carotid Occlusive DiseaseWith Extracranial Carotid Occlusive DiseaseClinical EvaluationClinical Evaluation

Hemispheric symptomsHemispheric symptoms include unilateral motor include unilateral motor weakness, sensory loss, speech or language weakness, sensory loss, speech or language disturbances, or visual field disturbances. disturbances, or visual field disturbances.

Vertebrobasilar symptomsVertebrobasilar symptoms include brainstem include brainstem symptoms (dysarthria, diplopia, dysphagia); symptoms (dysarthria, diplopia, dysphagia); cerebellar symptoms (limb or gait ataxia);and cerebellar symptoms (limb or gait ataxia);and simultaneous motor, sensory, and visual loss, simultaneous motor, sensory, and visual loss, which may be unilateral or bilateral.which may be unilateral or bilateral.

It is important to distinguish between It is important to distinguish between hemispheric and vertebrobasilar symptoms, hemispheric and vertebrobasilar symptoms, since patients may have vertebrobasilar since patients may have vertebrobasilar insufficiency and asymptomatic carotid insufficiency and asymptomatic carotid stenosis.stenosis.

Screening in asymptomaticsScreening in asymptomatics(including CABG candidates)(including CABG candidates)

In asymptomatic patients, there are no guidelines to In asymptomatic patients, there are no guidelines to support routine screening for carotid artery stenosis, support routine screening for carotid artery stenosis, except for some patients scheduled for CABG.except for some patients scheduled for CABG.

Prior to CABGPrior to CABG, carotid duplex screening is recommended , carotid duplex screening is recommended in asymptomatic patients within asymptomatic patients with

1.1. age greater than 65 years,age greater than 65 years,2.2. left main coronary stenosis,left main coronary stenosis,3.3. peripheral arterial disease,peripheral arterial disease,4.4. history of smoking,history of smoking,5.5. history of TIA or stroke, history of TIA or stroke, 6.6. carotid bruit carotid bruit In other patients with asymptomatic carotid bruits, In other patients with asymptomatic carotid bruits,

diagnostic tests for carotid disease should only be diagnostic tests for carotid disease should only be performed in those patients who are also considered good performed in those patients who are also considered good candidates for carotid revascularization.candidates for carotid revascularization.

Noninvasive TestingNoninvasive TestingDuplexDuplex

peak systolic velocitypeak systolic velocity is the single most is the single most accurate duplex parameter for accurate duplex parameter for determination of stenosis severity. determination of stenosis severity.

Compared with angiography, carotid Compared with angiography, carotid duplex has a sensitivity of 77% to 98% and duplex has a sensitivity of 77% to 98% and a specificity of 53% to 82% to identify or a specificity of 53% to 82% to identify or exclude an ICA stenosis greater than or exclude an ICA stenosis greater than or equal to 70% equal to 70%

Women have higher flow velocities than Women have higher flow velocities than men which may affect decisions about men which may affect decisions about revascularization.revascularization.

When duplex results are unclear, When duplex results are unclear, diagnostic accuracy may increase to diagnostic accuracy may increase to greater than 90% when it is used in greater than 90% when it is used in conjunction with CTA and/or MRAconjunction with CTA and/or MRA

TCDTCD TCD, with or without color-coding, measures TCD, with or without color-coding, measures

intracranial blood flow patterns, and indirectly intracranial blood flow patterns, and indirectly assesses the effects of stenoses proximal or distal assesses the effects of stenoses proximal or distal to the sites of insonationto the sites of insonation

when used as an adjunct to carotid duplex, when used as an adjunct to carotid duplex, sensitivity is nearly 90%sensitivity is nearly 90%

Impaired cerebrovascular reserve by TCD, Impaired cerebrovascular reserve by TCD, manifested by impaired cerebral blood flow manifested by impaired cerebral blood flow augmentation in response to breathholding or augmentation in response to breathholding or CO2 inhalation, may predict a 3-fold higher risk of CO2 inhalation, may predict a 3-fold higher risk of subsequent neurological events in asymptomatic subsequent neurological events in asymptomatic patients with extracranial carotid stenosispatients with extracranial carotid stenosis

MRAMRA The combination of duplex and MRA provides The combination of duplex and MRA provides

better concordance with digital subtraction better concordance with digital subtraction angiography than either test alone (combined angiography than either test alone (combined 96% sensitivity and 80% specificity), but is not 96% sensitivity and 80% specificity), but is not cost-effective for routine usecost-effective for routine use

Limitations :Limitations :1.1. inability to perform MRA due to claustrophobia, inability to perform MRA due to claustrophobia,

pacemakers, implantable defibrillators, and pacemakers, implantable defibrillators, and obesity;obesity;

2.2. misdiagnosis of subtotal stenoses as total misdiagnosis of subtotal stenoses as total occlusions;occlusions;

3.3. overestimation of carotid stenoses secondary to overestimation of carotid stenoses secondary to movement artifactmovement artifact

CTACTA CTA is useful whenCTA is useful when1.1. carotid duplex is ambiguous, carotid duplex is ambiguous, 2.2. visualization of aortic arch or high bifurcationvisualization of aortic arch or high bifurcation3.3. reliable differentiation of total and subtotal reliable differentiation of total and subtotal

occlusion,occlusion,4.4. assessment of ostial and tandem stenoses, assessment of ostial and tandem stenoses, 5.5. evaluation of carotid disease in patients with evaluation of carotid disease in patients with

arrhythmias, valvular heart disease, or arrhythmias, valvular heart disease, or cardiomyopathy.cardiomyopathy.

the sensitivity and specificity for detecting the sensitivity and specificity for detecting carotid stenosis greater than 70% was 85% to carotid stenosis greater than 70% was 85% to 95% and 93% to 98%, respectively95% and 93% to 98%, respectively

Carotid AngiographyCarotid Angiography

Catheter-based arch and cerebral artery Catheter-based arch and cerebral artery angiography is the reference standard for the angiography is the reference standard for the evaluation of carotid artery disease. evaluation of carotid artery disease.

The purpose of angiography is :The purpose of angiography is :1.1. to define the aortic arch type, to define the aortic arch type, 2.2. The configuration of the great vessels,The configuration of the great vessels,3.3. the presence of tortuosity and atherosclerotic the presence of tortuosity and atherosclerotic

disease in the arch and great vessels, anddisease in the arch and great vessels, and4.4. the condition of the intracranial circulation, the condition of the intracranial circulation,

particularly with respect to intracranial stenosis, particularly with respect to intracranial stenosis, aneurysm, arteriovenous malformations, and aneurysm, arteriovenous malformations, and patterns of collateral blood flow.patterns of collateral blood flow.

Angiographic Methods for Determining Carotid Angiographic Methods for Determining Carotid Stenosis SeverityStenosis Severity

ECST European Carotid Surgery Trial NASCET North American Symptomatic Carotid Endarterectomy TrialCC common carotid

Carotid AngiographyCarotid Angiographycomplicationscomplications

In patients with symptomatic cerebral In patients with symptomatic cerebral atherosclerosis undergoing diagnostic atherosclerosis undergoing diagnostic cerebral angiography, the risk of stroke is cerebral angiography, the risk of stroke is 0.5% to 5.7%, and the risk of TIA is 0.6% 0.5% to 5.7%, and the risk of TIA is 0.6% to 6.8% to 6.8%

In asymptomatic patients in the ACAS trial, In asymptomatic patients in the ACAS trial, stroke occurred in 1.2% of patients after stroke occurred in 1.2% of patients after angiography. angiography.

More recent studies reported neurological More recent studies reported neurological complication rates in less than 1%complication rates in less than 1%

Medical TherapyMedical TherapyRisk Factor ModificationRisk Factor Modification

Pharmacological TherapyPharmacological Therapyanti platelet agentsanti platelet agents

AspirinAspirin There are no data to support the use of aspirin in doses greater than 325 There are no data to support the use of aspirin in doses greater than 325

mg daily, even in patients with recurrent TIAs despite low-dose aspirin.mg daily, even in patients with recurrent TIAs despite low-dose aspirin.

DipyridamoleDipyridamole Extended-release dipyridamole plus aspirin was superior to aspirin alone for Extended-release dipyridamole plus aspirin was superior to aspirin alone for

the secondary prevention of MI, stroke, or vascular deaththe secondary prevention of MI, stroke, or vascular death

ThienopyridinesThienopyridines aspirin and clopidogrel appear to have similar efficacy for secondary aspirin and clopidogrel appear to have similar efficacy for secondary

prevention of stroke, but the combination may increase the risk of serious prevention of stroke, but the combination may increase the risk of serious bleeding, and is not superior to either drug alone.bleeding, and is not superior to either drug alone.

Antiplatelet Treatment FailuresAntiplatelet Treatment Failures addition of warfarinaddition of warfarin dual antiplatelet therapy with aspirin plus clopidogreldual antiplatelet therapy with aspirin plus clopidogrel triple drug therapy with aspirin and clopidogrel, plus either triple drug therapy with aspirin and clopidogrel, plus either

aspirin/dipyridamole, cilostazol, or warfarinaspirin/dipyridamole, cilostazol, or warfarin

Pharmacological TherapyPharmacological Therapy WarfarinWarfarin Indicated in primary and secondary prevention of stroke Indicated in primary and secondary prevention of stroke

in patients with atrial fibrillation. in patients with atrial fibrillation. antiplatelet therapy is favored over warfarin in patients antiplatelet therapy is favored over warfarin in patients

with carotid artery disease who are not at risk for with carotid artery disease who are not at risk for cardioembolic strokecardioembolic stroke

• Lipid-Lowering TherapyLipid-Lowering Therapy The National Cholesterol Education Program (NCEP) The National Cholesterol Education Program (NCEP)

guideline recommends statins in patients with prior TIA or guideline recommends statins in patients with prior TIA or stroke or carotid stenosis greater than 50% stenosis stroke or carotid stenosis greater than 50% stenosis

The American Stroke Association (ASA) also recommends The American Stroke Association (ASA) also recommends statins for patients with ischemic TIA or strokestatins for patients with ischemic TIA or stroke

Angiotensin-Converting Enzyme (ACE) Inhibitors and Angiotensin-Converting Enzyme (ACE) Inhibitors and Angiotensin Receptor Blockers (ARBs)Angiotensin Receptor Blockers (ARBs)

CEACEAHistorical PerspectiveHistorical Perspective

the first successful CEA was performed the first successful CEA was performed in1953, but was not reported until 1975in1953, but was not reported until 1975

in the late 1980s and early 1990s, 6 in the late 1980s and early 1990s, 6 randomized clinical trials established the randomized clinical trials established the efficacy of CEA plus aspirin compared with efficacy of CEA plus aspirin compared with aspirin alone in preventing stroke in aspirin alone in preventing stroke in patients with atherosclerotic carotid patients with atherosclerotic carotid bifurcation stenosisbifurcation stenosis

CEA CEA Randomized Clinical TrialsRandomized Clinical Trials

CEA CEA Randomized Clinical TrialsRandomized Clinical Trials

ConcernsConcerns The standard medical therapy for the randomized The standard medical therapy for the randomized

CEA trials was aspirin, and many physicians CEA trials was aspirin, and many physicians believe that “best medical therapy” with statins, believe that “best medical therapy” with statins, ACE inhibitors, and excellent risk factor control ACE inhibitors, and excellent risk factor control may be superior to aspirin alone may be superior to aspirin alone

standard practice after CEA does not include standard practice after CEA does not include routine evaluation by a neurologist. In a large routine evaluation by a neurologist. In a large meta-analysis of nearly 16,000 symptomatic meta-analysis of nearly 16,000 symptomatic patients with CEA, the 30-day risk of stroke and patients with CEA, the 30-day risk of stroke and death was 7.7% if a neurologist evaluated the death was 7.7% if a neurologist evaluated the patient, and 2.3% if a vascularsurgeon performed patient, and 2.3% if a vascularsurgeon performed the evaluation .the evaluation .

These data support the need for independent These data support the need for independent neurological evaluation following CEA or CAS.neurological evaluation following CEA or CAS.

CEA CEA IndicationsIndications

symptomatic patients with stenosis 50% to 99%, symptomatic patients with stenosis 50% to 99%, if the risk of perioperative stroke or death is less if the risk of perioperative stroke or death is less than 6%. than 6%.

For asymptomatic patients, AHA guidelines For asymptomatic patients, AHA guidelines recommend CEA for stenosis 60% to 99%, if the recommend CEA for stenosis 60% to 99%, if the risk of perioperative stroke or death is less than risk of perioperative stroke or death is less than 3%. 3%.

Although clinical trial data support CEA in Although clinical trial data support CEA in asymptomatic patients with carotid stenosis 60% asymptomatic patients with carotid stenosis 60% to 79%, the AHA guidelines indicate that to 79%, the AHA guidelines indicate that somephysicians delay revascularization until somephysicians delay revascularization until there is greater than 80% stenosis in there is greater than 80% stenosis in asymptomatic patientsasymptomatic patients

CEA CEA IndicationsIndications

other important clinical factorsother important clinical factors : :1.1. anticipated life expectancy,anticipated life expectancy,2.2. age, age, 3.3. gender,gender,4.4. the presence of other comorbid medical conditionsthe presence of other comorbid medical conditions the documented outcomes of the surgeon the documented outcomes of the surgeon

performing the CEAperforming the CEA,, These clinical factors and surgical outcomes must be These clinical factors and surgical outcomes must be

considered when making recommendations to a specific considered when making recommendations to a specific patient.patient.

the 2005 guidelines from the American Academy of Neurology the 2005 guidelines from the American Academy of Neurology recommend that eligible patients patients should be 40 to 75 recommend that eligible patients patients should be 40 to 75 years old and have a life expectancy of at least 5 years .years old and have a life expectancy of at least 5 years .

In symptomatic patients, the greatest benefits of CEA are in In symptomatic patients, the greatest benefits of CEA are in elderly men with hemispheric, not ocular, symptoms elderly men with hemispheric, not ocular, symptoms

ContraindicationsContraindications

aspirin and risk factor modification aspirin and risk factor modification instead of CEA when the predicted instead of CEA when the predicted perioperative risk of stroke or death perioperative risk of stroke or death waswas

1.1. greater than 3% for asymptomatic greater than 3% for asymptomatic patients, patients,

2.2. greater than 6% for symptomatic greater than 6% for symptomatic patients, patients,

3.3. greater than 10% for repeat CEAgreater than 10% for repeat CEA

High-Risk Criteria for CEAHigh-Risk Criteria for CEA

Potential Complications of Carotid Potential Complications of Carotid EndarterectomyEndarterectomy

Risk for Periprocedural Stroke or Death AfterRisk for Periprocedural Stroke or Death AfterCarotid EndarterectomyCarotid Endarterectomy

CASCASHistorical PerspectiveHistorical Perspective

The first balloon angioplasty for The first balloon angioplasty for carotid stenosis was performed in carotid stenosis was performed in 19791979

the first balloon-expandable stent the first balloon-expandable stent was deployed in the carotid artery in was deployed in the carotid artery in 19891989

TechniqueTechnique

The goal of CAS is to passivate the lesion and decrease the risk of stroke; a The goal of CAS is to passivate the lesion and decrease the risk of stroke; a moderate residual stenosis (30% to 40%) is acceptable. moderate residual stenosis (30% to 40%) is acceptable.

Carotid stent operators generally do not pursue a perfect angiographic Carotid stent operators generally do not pursue a perfect angiographic result for several reasons. result for several reasons.

First, multiple and aggressive balloon inflations appear to increase the First, multiple and aggressive balloon inflations appear to increase the risk of complications. Accordingly, 2 balloon inflations are reasonable, 1 risk of complications. Accordingly, 2 balloon inflations are reasonable, 1 before and 1 after stent deployment. before and 1 after stent deployment.

Second, the most common reason for moderate residual stenosis after Second, the most common reason for moderate residual stenosis after stenting is heavy calcification of the target lesion, which generally does not stenting is heavy calcification of the target lesion, which generally does not respond to repeated balloon inflations. respond to repeated balloon inflations.

Third, self-expanding stents have a tendency to continue to expand the Third, self-expanding stents have a tendency to continue to expand the lumen after the procedure, and it is possible that a moderate residual lumen after the procedure, and it is possible that a moderate residual stenosis immediately after intervention may remodel into a mild residual stenosis immediately after intervention may remodel into a mild residual stenosis a few months later.stenosis a few months later.

Finally, hemodynamic perturbations such as vasovagal or vasodepressor Finally, hemodynamic perturbations such as vasovagal or vasodepressor reactions may limit the number of balloon inflations. reactions may limit the number of balloon inflations.

In any case, late endothelialization of the stent will In any case, late endothelialization of the stent will likely decrease the risk of stroke, even if a moderate likely decrease the risk of stroke, even if a moderate residual stenosis persists.residual stenosis persists.

Carotid Embolic Protection Device and Stent Carotid Embolic Protection Device and Stent DeploymentDeployment

Carotid StentsCarotid Stents

Comparison of Proximal and Distal Embolic Comparison of Proximal and Distal Embolic ProtectionProtection

Comparison of Selected Distal Embolic Comparison of Selected Distal Embolic Protection FiltersProtection Filters

Examples of Filter-Type Embolic Protection Examples of Filter-Type Embolic Protection DevicesDevices

Carotid Artery Stent RegistriesCarotid Artery Stent Registries

Randomized CAS Versus CEA TrialsRandomized CAS Versus CEA Trials

Nonatherosclerotic DiseaseNonatherosclerotic Disease

Carotid artery dissectionCarotid artery dissection : 10% to 25% of strokes in : 10% to 25% of strokes in younger people and 2% of all ischemic stroke younger people and 2% of all ischemic stroke

About 50% of patients with carotid dissection do not have About 50% of patients with carotid dissection do not have identifiable predisposing factors to dissection, such as identifiable predisposing factors to dissection, such as traumatic injury to the head and neck.traumatic injury to the head and neck.

Antithrombotic therapy is usually sufficient, but CAS may Antithrombotic therapy is usually sufficient, but CAS may be useful in patients with recurrent ischemia and persistent be useful in patients with recurrent ischemia and persistent significant stenosis significant stenosis

External beam radiation for head and neck cancerExternal beam radiation for head and neck cancer Lesions are often long, involve the CCA, and are surgical Lesions are often long, involve the CCA, and are surgical

challenges. challenges. Only anecdotal reportsOnly anecdotal reports on CAS exist for radiation-induced carotid artery stenosison CAS exist for radiation-induced carotid artery stenosis

CASCASIndicationsIndications

potential safety advantages when potential safety advantages when applied to applied to high-riskhigh-risk patients with patients with

symptomatic stenosis greater than symptomatic stenosis greater than 50% and 50% and

asymptomatic stenosis greater than asymptomatic stenosis greater than 80%80%

CMS Reimbursement Criteria for CASCMS Reimbursement Criteria for CAS

Contraindications to Carotid Artery StentingContraindications to Carotid Artery Stenting

Potential Complications of Carotid Artery StentingPotential Complications of Carotid Artery Stenting

AHA/ASA Recommendations for Revascularization AHA/ASA Recommendations for Revascularization in Symptomatic Patientsin Symptomatic Patients

Revascularization in AsymptomaticRevascularization in AsymptomaticPatients at Low Risk for CEAPatients at Low Risk for CEA

The1998 revised AHA guidelines The1998 revised AHA guidelines recommendationrecommendation

CEA for asymptomatic stenosis greater CEA for asymptomatic stenosis greater than 60% for patients with surgical risk than 60% for patients with surgical risk less than 3%less than 3%

and for asymptomatic stenosis greater and for asymptomatic stenosis greater than 75% for patients with surgical risk 3% than 75% for patients with surgical risk 3% to 5%. to 5%.

It is also notable that the AHA guidelines It is also notable that the AHA guidelines did not clearly indicate whether stenosis did not clearly indicate whether stenosis severity should be judged by angiographic severity should be judged by angiographic or noninvasive techniquesor noninvasive techniques

Revascularization in AsymptomaticRevascularization in AsymptomaticPatients at High Risk for CEAPatients at High Risk for CEA

In the meantime, to gather additional In the meantime, to gather additional data, it is reasonable to enroll these data, it is reasonable to enroll these high-risk patients in nonrandomized high-risk patients in nonrandomized registries.registries.

AgeAge

Medical therapy alone is especially reasonable for Medical therapy alone is especially reasonable for elderly patients with a life expectancy less than 5 elderly patients with a life expectancy less than 5 years.years.

For symptomatic patients with life expectancy For symptomatic patients with life expectancy greater than 5 years, revascularization is greater than 5 years, revascularization is reasonable, particularly in men. reasonable, particularly in men.

The choice of revascularization technique is less The choice of revascularization technique is less certain, although available data suggest that CAS certain, although available data suggest that CAS may be safer and less invasive than CEA.may be safer and less invasive than CEA.

Further study is needed to assess the relative Further study is needed to assess the relative merits of medical therapy and CAS, but in the merits of medical therapy and CAS, but in the meantime, continued enrollment in one of the meantime, continued enrollment in one of the high-risk CAS registries is reasonablehigh-risk CAS registries is reasonable

Need for CABG in Patients With Carotid StenosisNeed for CABG in Patients With Carotid Stenosis

CABG alone is reasonable for patients with CABG alone is reasonable for patients with asymptomatic carotid stenosis and critical asymptomatic carotid stenosis and critical left main disease, refractory acuteleft main disease, refractory acute

coronary syndromes, or other indications coronary syndromes, or other indications for urgent CABGfor urgent CABG

patients with recent (less than 2 weeks) patients with recent (less than 2 weeks) TIA and carotid stenosis greater than 50% TIA and carotid stenosis greater than 50% should be considered for urgent CEA, if should be considered for urgent CEA, if CABG can be safely deferred for several CABG can be safely deferred for several days.days.

Need for CABG in Patients With Carotid Need for CABG in Patients With Carotid StenosisStenosis

The most recent guidelines suggest that CEA is The most recent guidelines suggest that CEA is recommended before or concomitant to CABG in recommended before or concomitant to CABG in patients with symptomatic carotid stenosis patients with symptomatic carotid stenosis greater than 50% or asymptomatic carotid greater than 50% or asymptomatic carotid stenosis greater than 80%.stenosis greater than 80%.

If the procedures are to be staged, complication If the procedures are to be staged, complication rates are lower when carotid revascularization rates are lower when carotid revascularization precedes CABG.precedes CABG.

For patients who can defer CABG for 4 to 5 For patients who can defer CABG for 4 to 5 weeks, enrollment in one of the high-risk CAS weeks, enrollment in one of the high-risk CAS registries is a potential option. Since CAS patients registries is a potential option. Since CAS patients are treated with clopidogrel for one month, it is are treated with clopidogrel for one month, it is best to defer CABG for 5 weeks.best to defer CABG for 5 weeks.

Preoperative Assessment Prior toPreoperative Assessment Prior toNoncardiac SurgeryNoncardiac Surgery

in the absence of symptoms or in the absence of symptoms or neurological findings, so carotid neurological findings, so carotid revascularization is not necessary revascularization is not necessary before noncardiac surgery.before noncardiac surgery.

carotid revascularization is carotid revascularization is recommended before elective recommended before elective surgery for symptomatic carotid surgery for symptomatic carotid stenosis greater than 50%.stenosis greater than 50%.

Peripheral arterial disease-1 carotid

Documents

carotid stenosis greater

carotid sinus

carotid atherosclerosis

carotid baroreceptors

progressive carotid

stenosis severity

heart disease

intracranial disease