Carotid Artery Stenosis

Classify stenosis as symptomatic when a recent TIA, amaurosis fugax, or nondisabling ischemic stroke is referable to the ipsilateral carotid artery; CREST defined symptomatic status by recent neurologic events and considered events more than 180 days earlier asymptomatic. ACCACCCarotid Revascularization Endarterectomy vs. Stenting Trial - American College of Cardiology A focal event in the opposite hemisphere, posterior circulation symptoms, or a nonfocal syndrome should not by itself establish causality for an ipsilateral extracranial internal carotid lesion.

For a patient with recent ipsilateral retinal or cerebral ischemia and an associated stenosis of at least 50%, obtain expedited vascular imaging and begin evaluation for revascularization. The largest benefit is observed with 70% to 99% symptomatic stenosis. Wolters KluwerWolters KluwerSymptomatic Cervical Carotid Artery Stenosis:... : Annals of ... - Ovid Do not delay definitive vascular assessment while awaiting recurrent events: treatment guidance supports revascularization within 2 weeks of the index event. NEJM+1NEJMCarotid StenosisjaccCarotid Artery Stenting: JACC State-of-the-Art Review

Perform carotid duplex ultrasound as the initial noninvasive study for suspected extracranial carotid bifurcation disease. Duplex is widely used as the primary screening test and can efficiently identify patients who need CTA, MRA, or procedural evaluation; diagnostic accuracy is strongest for separating less than 50% from 50% to 99% stenosis. PubMed+1PubMedReappraisal of velocity criteria for carotid bulb/internal carotid artery stenosis utilizing high-resolution B-mode ultrasound validated with computed tomography angiography - PMCPubMedDuplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments - PMC In a technically adequate laboratory, Society of Radiologists in Ultrasound criteria use visible plaque plus internal carotid artery peak systolic velocity of 125 to 230 cm/s, an ICA/CCA peak systolic velocity ratio of 2.0 to 4.0, and end-diastolic velocity of 40 to 100 cm/s for 50% to 69% stenosis. PubMedPubMedReappraisal of velocity criteria for carotid bulb/internal carotid artery stenosis utilizing high-resolution B-mode ultrasound validated with computed tomography angiography - PMC

For duplex findings suggesting 70% or greater stenosis, review the full velocity and plaque data rather than a single velocity value. ICA/CCA peak systolic velocity ratio greater than 4.0 supports at least 70% stenosis, while a ratio greater than 5.0 supports at least 90% stenosis in recommended criteria. ScienceDirectScienceDirectDuplex Ultrasound Criteria for Defining the Severity of Carotid Stenosis - ScienceDirect Velocity thresholds are laboratory- and method-dependent; increasing the threshold increases specificity but decreases sensitivity. PubMed+1PubMedReappraisal of velocity criteria for carotid bulb/internal carotid artery stenosis utilizing high-resolution B-mode ultrasound validated with computed tomography angiography - PMCPubMedDuplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments - PMC Therefore, a potentially intervention-eligible duplex result that is technically limited, inconsistent with the clinical syndrome, or affected by heavy calcification warrants CTA or MRA confirmation.

Measure and report angiographic stenosis with the NASCET method when correlating CTA, MRA, or digital subtraction angiography to trial-based treatment thresholds. A 70% NASCET stenosis approximates 82% using ECST measurement; mixing these systems can misclassify a patient across an intervention threshold. PubMedPubMedWhy are we still debating criteria for carotid artery stenosis? CTA evaluates intracranial circulation but is susceptible to calcific plaque artifact and requires intravenous contrast and radiation; MRA avoids radiation but may have motion and acquisition limitations. PubMedPubMedWhy are we still debating criteria for carotid artery stenosis?

Prescribe the core elements of vascular disease management for every patient with carotid atherosclerosis: antiplatelet therapy, aggressive dyslipidemia treatment, blood-pressure treatment to national targets, diabetes treatment to national targets, smoking cessation, dietary modification, and exercise. jaccjaccHow Recent Data Have Impacted the Treatment of Internal Carotid Artery Stenosis Continue this approach before and after CEA or CAS because optimal medical therapy is a critical component of every revascularization strategy. jaccjaccCarotid Artery Stenting: JACC State-of-the-Art Review

For asymptomatic stenosis, use the low contemporary stroke rate on optimal medical therapy as the comparator for an elective procedure. Reported annual stroke risk is below 1% with optimal medical therapy, while pivotal asymptomatic revascularization trials predated current atherosclerosis treatment standards. jacc+1jaccCarotid Artery Stenting in Asymptomatic Carotid Artery Stenosis: JACC Review Topic of the WeekACCAsymptomatic Carotid Trial I - American College of Cardiology This uncertainty increases the importance of individualized assessment of competing comorbidity, anticipated longevity, lesion severity, and the center's actual perioperative outcomes.

Carotid endarterectomy and carotid artery stenting are the principal revascularization procedures for extracranial carotid stenosis. JAMA+1JAMACarotid Endarterectomy and Carotid Artery Stenting in the ...NEJMStenting versus Endarterectomy for Treatment of Carotid-Artery ... In symptomatic disease, current recommendations support revascularization in patients with at least 50% stenosis, especially 70% to 99%, and recommend performing it within 2 weeks of the index event. jacc+1jaccCarotid Artery Stenting: JACC State-of-the-Art ReviewWolters KluwerSymptomatic Cervical Carotid Artery Stenosis:... : Annals of ... - Ovid Use CEA or CAS only after confirming that the lesion explains the ipsilateral event and that expected procedural risk is acceptable.

CEA is the established surgical option; CAS was developed particularly as an alternative for patients at increased surgical risk for perioperative complications from CEA. jaccjaccCarotid Artery Stenting: JACC State-of-the-Art Review CAS introduces a catheter-related risk of cerebral embolization and consequent perioperative stroke. Oxford AcademicOxford AcademicTreatment of carotid stenosis: surgery and stent in comparison In CREST, symptomatic patients could enter with at least 50% angiographic stenosis, at least 70% by ultrasound, or at least 70% by CTA or MRA, demonstrating that imaging modality and measurement convention must be reconciled before assigning a procedural indication. ACCACCCarotid Revascularization Endarterectomy vs. Stenting Trial - American College of Cardiology

For asymptomatic disease, revascularization remains selective rather than routine. Multispecialty guidance cited a class IIa recommendation for revascularization of greater than 70% asymptomatic ICA stenosis when perioperative stroke, MI, and death risk is low. jaccjaccCarotid Artery Stenting in Asymptomatic Carotid Artery Stenosis: JACC Review Topic of the Week ACT I found protected CAS noninferior to CEA among low-risk asymptomatic patients, but did not include a contemporary medical-therapy-only control group. ACCACCAsymptomatic Carotid Trial I - American College of Cardiology The decision is therefore not simply CEA versus CAS; first determine whether either procedure adds sufficient benefit beyond intensive medical treatment.

At each follow-up, ask specifically about new ipsilateral transient monocular visual loss, focal hemispheric deficits, or nondisabling stroke. A new event reclassifies a previously asymptomatic lesion as symptomatic and should trigger expedited repeat vascular imaging and revascularization review under the 2-week timing principle. NEJM+2NEJMCarotid StenosisjaccCarotid Artery Stenting: JACC State-of-the-Art ReviewACCCarotid Revascularization Endarterectomy vs. Stenting Trial - American College of Cardiology Reconcile any new imaging with prior NASCET-equivalent measurements rather than comparing percentages derived from different methods. PubMedPubMedWhy are we still debating criteria for carotid artery stenosis?

Repeat or escalate imaging when the initial duplex study is technically limited, when cross-sectional imaging and duplex are discordant near an intervention threshold, or when lesion progression would change candidacy. Duplex accuracy is influenced by velocity threshold selection, plaque visualization, operator performance, contralateral occlusion, and inability to distinguish subtotal from total occlusion reliably in some cases. PubMed+2PubMedReappraisal of velocity criteria for carotid bulb/internal carotid artery stenosis utilizing high-resolution B-mode ultrasound validated with computed tomography angiography - PMCPubMedDuplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments - PMCPubMedWhy are we still debating criteria for carotid artery stenosis? CTA or MRA can provide confirmatory extracranial and intracranial anatomic information, with modality-specific limitations considered before ordering. ScienceDirect+1ScienceDirectDuplex Ultrasound Criteria for Defining the Severity of Carotid Stenosis - ScienceDirectPubMedWhy are we still debating criteria for carotid artery stenosis?

For patients managed medically, reassess adherence to antiplatelet therapy, dyslipidemia treatment, blood-pressure and diabetes control, smoking cessation, diet, and exercise rather than treating a stable imaging percentage as the only outcome. jacc+1jaccHow Recent Data Have Impacted the Treatment of Internal Carotid Artery StenosisjaccCarotid Artery Stenting: JACC State-of-the-Art Review For asymptomatic patients, a new procedure discussion should explicitly revisit the low stroke rate on optimal medical therapy, procedural risk, and comorbid competing risk. jacc+1jaccCarotid Artery Stenting in Asymptomatic Carotid Artery Stenosis: JACC Review Topic of the WeekACCAsymptomatic Carotid Trial I - American College of Cardiology