ISCHEMIC STROKE
Carotid artery web
Created 12/01/2022, last revision 30/11/2023
Definition
- the carotid artery web is characterized by a thin membrane extending from the posterior wall of the carotid bulb into the lumen, just above the bifurcation; it is considered a variant of fibromuscular dysplasia [Kim, 2019]
- various synonyms are used: carotid weblike formation, carotid pseudovalvular fold, carotid diaphragm
- a relatively rare vascular pathology, increasingly recognized as an important cause of ischemic stroke in patients without traditional cardiovascular risk factors
- it is a significant risk factor for cryptogenic and recurrent ischemic stroke (the incidence rate of carotid web in cryptogenic stroke is 8.9% vs. 1.9% in the control group) [Coutinho, 2017]
- its thrombogenic potential is caused by blood stasis along the downstream surface of the web, which can lead to intracranial thromboembolism [Compagne, 2019]
Epidemiology
- a relatively rare finding (approximately 1-2.5% of CTAs performed) (Coutinho, 2017) [Compagne, 2017]
- more common in women
Clinical presentation
- often an asymptomatic, incidental lesion
- thrombus formation can lead to recurrent stroke or transient ischemic attack (TIA)
- recurrence occurs in up to 29% of patients despite medical treatment [Haussen, 2019]
- the web is a significant cause of “cryptogenic stroke” in young patients
Diagnostic evaluation
- neurosonology
- an echogenic lesion in the posterior wall of the ICA above the bifurcation
- hypoechoic thrombus with possible significant stenosis may be seen
- method is less reliable than CT angiography (CTA)
- CTA/MRA
- optimal method of choice
- view both axial and sagittal sections
- the carotid web appears as a thin shelf-like or linear filling defect in the posterior wall of the carotid bulb
- hypodense thrombus is found in up to 25% of cases
- DSA
- gold standard
- carotid web is typically detected during an endovascular procedure
- always look for oblique projections
- signs of contrast stagnation may sometimes be visible in the venous phase
Management
Acute stroke therapy
- recanalization therapy for all eligible patients
- antithrombotic drugs for the rest
Stroke prevention
- there is little data to establish a clear preference between medication and CEA/CAS); some smaller series report a lower risk of stroke with invasive therapy
- data on the management of asymptomatic lesions is lacking
- medical treatment – antiplatelet drugs
- recommended for all stroke patients (AHA/ASA 2021 1/B-NR)
- consider in asymptomatic lesions, though the benefit remains unclear
- indication for anticoagulation is unclear (may be considered in patients with proven concurrent thrombosis)
- CEA/CAS
- medical management alone may not provide sufficient protection due to the high recurrence risk [Guglielmi, 2021] [Zhang, 2018]
- invasive therapy should be considered for patients with webs causing significant stenosis and recurrent strokes occurring despite the best medical treatment (BMT) (AHA/ASA 2021 2b/C-LD)
FAQs
- a rare vascular abnormality characterized by a shelf-like intraluminal membrane in the carotid bulb, which can predispose individuals to ischemic stroke
- its exact prevalence is not well-documented due to its rarity and often asymptomatic nature
- vascular imaging, such as carotid ultrasound, CT or MR angiography, is used to visualize the web-like structure in the artery
- often asymptomatic; rarely it may manifest as ischemic stroke
- treatment options include antithrombotic therapy, such as antiplatelet or anticoagulant medications, and in some cases, surgical intervention like carotid endarterectomy or stenting
- the decision for surgery depends on individual risk factors, symptoms, and the severity of the web
- medical management is often the first-line treatment
- vascular imaging follow-up (usually with ultrasound) can monitor the condition and assess the effectiveness of treatment