Carotid web

Complex MONDO:0979323 Pathograph 16 Show in embeddings browser Vasculopathy Cerebrovascular Disease

Carotid web is a non-atherosclerotic intimal shelf projecting into the carotid bulb or proximal internal carotid artery, most often from the posterior wall. Histology supports an intimal fibromuscular dysplasia phenotype, although its origin is incompletely understood. Disturbed flow and stasis in the web pouch favor local thrombosis and downstream artery-to-artery embolism. Webs may be incidental or associated with ipsilateral ischemic stroke, transient ischemic attack, or retinal ischemia; a severe flow-limiting stenosis is not required.

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1
Definitions
4
Pathophys.
2
Histopath.
6
Phenotypes
16
Pathograph
6
Medical Actions
6
Trials
20
References
1
Deep Research
📘

Definitions

1
Multiplanar CTA definition of carotid web
A thin shelf-like filling defect of the posterior carotid bulb seen on oblique sagittal CTA and as a septum on axial images. The imaging lesion may be present without a clinical ischemic event.
CASE_DEFINITION Structural imaging definition; attribution of a stroke requires clinical and etiologic assessment.
Show evidence (1 reference)
PMID:26228877 SUPPORT DIRECT BACKGROUND Human Clinical
"A carotid web was defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation on oblique sagittal section CTA that was seen as a septum on axial CTA."
The operational imaging definition requires the shelf on oblique sagittal reconstruction and septum on axial images.
⚙

Pathophysiology

4
Intimal shelf lesion of the carotid bulb
Mechanism confidence: Established
Eccentric fibrous and myxoid intimal tissue forms a shelf projecting into the arterial lumen. Smooth-muscle-like spindle cells are embedded in extracellular matrix; the lesion differs from a lipid-rich atheroma.
vascular associated smooth muscle cell CL:0000359 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves vascular associated smooth muscle cell (CL:0000359). CL:0000359 is a cell type from the Cell Ontology.
internal carotid artery UBERON:0001532 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in internal carotid artery (UBERON:0001532). UBERON:0001532 is an anatomical location from the Uberon multi-species anatomy ontology. carotid sinus UBERON:0003708 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in carotid sinus (UBERON:0003708). UBERON:0003708 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Disturbed carotid flow and stasis The intraluminal shelf produces a recirculation pouch with slow washout.
Show evidence (2 references)
PMID:40873957 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Histopathologic analysis consistently demonstrated fibrovascular tissue with intimal fibroid hyperplasia and myxoid degeneration, without lipid-rich plaques or inflammatory infiltrates."
Three surgically selected symptomatic patients had non-atheromatous intimal lesions; the series does not exclude coexisting atherosclerosis in other patients.
PMID:40494576 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"The common histological feature of the carotid web is eccentric intimal hyperplasia, characterized by spindle cells (consistent with migrated vascular smooth muscle cells) intermingled within an abundant loose extracellular matrix."
Summarizes the cellular and matrix composition of resected webs, not an experimentally established developmental origin.
Disturbed carotid flow and stasis
Mechanism confidence: Provisional
The web geometry produces local flow separation, recirculation, low velocity and prolonged residence time. These abnormalities can occur with modest luminal narrowing.
internal carotid artery UBERON:0001532 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in internal carotid artery (UBERON:0001532). UBERON:0001532 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Web-associated mural thrombosis Slow washout favors local accumulation of thrombotic material.
Show evidence (1 reference)
DOI:10.1038/s41598-024-60666-7 SUPPORT DIRECT PRIMARY RESULT Computational
"Patients with CaW had significantly larger regions containing low shear rate, high OSI, low velocity, and flow stasis in comparison to subjects with mild atherosclerosis or normal bifurcations."
Patient-specific CFD assessed flow surrogates in 13 web bifurcations, seven atherosclerotic bifurcations and six contralateral normal bifurcations; it did not measure platelet activation or prospective stroke risk.
Web-associated mural thrombosis
Mechanism confidence: Provisional
Thrombus forms in or adheres to the pouch of the web. Serial imaging can show its appearance and resolution, and resected specimens can contain adherent mural thrombus.
blood coagulation GO:0007596 ↑ INCREASED Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased blood coagulation (GO:0007596). GO:0007596 is a biological process from the Gene Ontology.
internal carotid artery UBERON:0001532 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in internal carotid artery (UBERON:0001532). UBERON:0001532 is an anatomical location from the Uberon multi-species anatomy ontology.
Downstream
Artery-to-artery embolization Fragments of web-associated thrombus can be carried into downstream cerebral or retinal arteries.
Show evidence (2 references)
PMID:26228877 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Specimens from another case contained a thick fibrous intimal cushion with a recent mural thrombus"
Direct histology documents thrombus associated with the intimal lesion.
PMID:26228877 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"In 2 patients, thrombus-like material was seen at the site of the carotid web, with changing morphology on serial CTAs, despite concurrent antiplatelet therapy."
Serial imaging supports dynamic local thrombus formation, without establishing treatment efficacy.
Artery-to-artery embolization
Mechanism confidence: Provisional
Detachment and transport of web-associated thrombus can occlude downstream vessels. Ischemic manifestations depend on the affected vascular territory and whether perfusion is restored before infarction.
Downstream
Embolic ischemic stroke Persistent downstream occlusion can cause cerebral infarction.
Recurrent ischemic stroke A persistent thrombogenic lesion can produce further ipsilateral embolic events.
Transient ischemic attack Transient downstream ischemia can resolve without an established infarct.
Hemiparesis Ischemic injury involving motor pathways can cause unilateral weakness.
Aphasia Dominant-hemisphere ischemia can impair language.
Central retinal artery occlusion An embolus entering the retinal arterial circulation can produce retinal infarction.
Show evidence (1 reference)
PMID:34102760 SUPPORT DIRECT BACKGROUND Human Clinical
"The widely accepted mechanism of cerebral ischemic events (CIE) is an artery-to-artery embolism through blood stasis rostral to CaW, thrombus formation and clot fragmentation scattered by the blood flow"
The cohort introduction summarizes the proposed embolic pathway; this is background mechanistic evidence.
✶

Histopathology

2
Fibrous and myxoid intimal hyperplasia
Resected webs contain eccentric fibrovascular intimal tissue with myxoid change. Classic lipid-rich atheroma was absent in a three-patient series, but concurrent atheromatous changes occur in other cohorts.
Show evidence (2 references)
PMID:40873957 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Histopathologic analysis consistently demonstrated fibrovascular tissue with intimal fibroid hyperplasia and myxoid degeneration, without lipid-rich plaques or inflammatory infiltrates."
Three surgically selected symptomatic patients had non-atheromatous intimal lesions; the series does not exclude coexisting atherosclerosis in other patients.
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Notably, concurrent atheromatous changes were noted in 6 patients."
Prevents generalizing the absence of plaque in a small case series.
Adherent mural thrombus
Thrombus can adhere to or be embedded in the intimal shelf, supporting a local embolic source; it is not present in every resected specimen.
Show evidence (1 reference)
PMID:26228877 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Specimens from another case contained a thick fibrous intimal cushion with a recent mural thrombus"
Direct histology documents thrombus associated with the intimal lesion.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Carotid web Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

6
Cardiovascular 4
Embolic ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Ischemic stroke (HP:0002140). HP:0002140 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:37724713 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Between June 2019 and December 2021, 244 cases were submitted by 14 centers, 42 rejected, and 202 included (IS, 91.6%; TIA, 7.9%; retinal infarction, 0.5%; mean age, 50.8 ± 12.2 years; female, 62.9%; Caucasian, 47.5%; Afro-Caribbean, 20.3%)."
The adjudicated French registry selected symptomatic cases; these proportions are not penetrance or population prevalence.
Recurrent ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Ischemic stroke (HP:0002140), qualified as temporality recurrent. HP:0002140 is a phenotype from the Human Phenotype Ontology.
Temporal: RECURRENT
Show evidence (1 reference)
PMID:39215397 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"11% (3/27) of patients with ipsilateral carotid artery webs experienced recurrent ischemic stroke and LVO."
Three early recurrences occurred among 27 web patients in a single-center anterior-circulation thrombectomy cohort. This estimate does not apply to all incidentally detected webs.
Transient ischemic attack HP:0002326 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Transient ischemic attack (HP:0002326). HP:0002326 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:37724713 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Between June 2019 and December 2021, 244 cases were submitted by 14 centers, 42 rejected, and 202 included (IS, 91.6%; TIA, 7.9%; retinal infarction, 0.5%; mean age, 50.8 ± 12.2 years; female, 62.9%; Caucasian, 47.5%; Afro-Caribbean, 20.3%)."
The adjudicated French registry selected symptomatic cases; these proportions are not penetrance or population prevalence.
Central retinal artery occlusion HP:0025342 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Central retinal artery occlusion (HP:0025342). HP:0025342 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:34102760 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"At inclusion, 13 patients experienced a TIA as first-ever CIE and two patients suffered from a central retina artery infarction without any recent lesion on admission MRI."
Two retinal arterial infarctions were observed among 92 selected symptomatic patients; this is not a general-population frequency.
Nervous System 2
Hemiparesis HP:0001269 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hemiparesis (HP:0001269). HP:0001269 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40776764 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation."
Reports presenting focal deficits in the symptomatic surgical/interventional cohort.
Aphasia HP:0002381 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Aphasia (HP:0002381). HP:0002381 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40776764 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation."
Documents aphasia among common presenting symptoms in the cohort.
💊

Medical Actions

6
Antithrombotic medical therapy after symptomatic ischemia
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: acetylsalicylic acid CHEBI:15365 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses acetylsalicylic acid (CHEBI:15365). CHEBI:15365 is a therapeutic agent from Chemical Entities of Biological Interest. Vitamin K Antagonist NCIT:C173064 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses Vitamin K Antagonist (NCIT:C173064). NCIT:C173064 is a therapeutic agent from the NCI Thesaurus.
Platform: Small molecule
Antiplatelet therapy is commonly used after symptomatic events, including alongside revascularization. Anticoagulation has also been used in selected patients or for other indications. The optimal agent, combination and duration for the web itself are not established; recurrence can occur on therapy.
Target Phenotypes: Ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Ischemic stroke (HP:0002140). HP:0002140 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:40494576 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"Treatment options in symptomatic cases include medical therapy (single or dual antiplatelets) or interventional approach (surgery or stenting), but there are no randomized controlled trials about therapy."
Review synthesis documents available approaches and the absence of randomized comparative treatment evidence.
PMID:34102760 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All patients treated with carotid surgery or stenting received long-term antithrombotic therapy with aspirin (n=21) or vitamin K antagonist (n=2) that was ongoing at the end of follow-up."
Documents agents used in this cohort; it does not prescribe a universal regimen.
PMID:39215397 SUPPORT DIRECT BACKGROUND Human Clinical
"the benefit of immediate dual antiplatelet or anticoagulation therapy remains unclear, particularly in medium to large strokes where there is an elevated risk of hemorrhage"
The discussion highlights uncertainty about escalation of antithrombotic treatment, not a demonstrated benefit.
Carotid endarterectomy
Action: Carotid EndarterectomyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Carotid Endarterectomy (NCIT:C157807). NCIT:C157807 is a clinical intervention from the NCI Thesaurus. NCIT:C157807
Platform: Surgery
Selected symptomatic patients undergo surgical excision of the web, removing a local embolic source and permitting histological examination. Retrospective series report low recurrence but have no randomized medical control; cranial-nerve injury is a procedural risk.
Mechanism Target:
INHIBITS Artery-to-artery embolization — Excision removes the structural source from which local thrombi can embolize.
Show evidence (1 reference)
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Among 39 patients with symptomatic carotid web, 34 underwent CEA with histopathological confirmation of the diagnosis, characterized by focal eccentric intimal fibromyxoid tissue, fibromuscular dysplasia, hyperplasia, or thickening."
Surgery removed the lesion and supplied tissue for histological diagnosis in this selected retrospective cohort.
Show evidence (4 references)
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Among 39 patients with symptomatic carotid web, 34 underwent CEA with histopathological confirmation of the diagnosis, characterized by focal eccentric intimal fibromyxoid tissue, fibromuscular dysplasia, hyperplasia, or thickening."
Surgery removed the lesion and supplied tissue for histological diagnosis in this selected retrospective cohort.
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"At a median follow-up of 29 months, no patients experienced recurrent stroke (95% CI: 0%-10%), and the median modified Rankin Scale score was 1 (0-1)."
The confidence interval and lack of randomized controls prevent interpreting zero observed recurrences as zero future risk.
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Two patients experienced transient, minor cranial nerves injuries (hypoglossal nerve and marginal mandibular branch) after CEA."
Documents procedural morbidity.
+ 1 more reference
Carotid artery stenting
Action: Endovascular StentingNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Endovascular Stenting (NCIT:C157840). NCIT:C157840 is a clinical intervention from the NCI Thesaurus. NCIT:C157840
Platform: Device
Stenting across the web is used to exclude the thrombogenic pouch in selected symptomatic patients. The 71-person multicenter series included 48 stenting and 23 endarterectomy procedures, with one perioperative stroke overall and one recurrent stroke in the stenting group. Procedure selection was not randomized and there was no medical-only control.
Mechanism Target:
INHIBITS Disturbed carotid flow and stasis — Stent apposition can exclude the web pouch from retrograde filling, reducing the local flow disturbance that promotes thrombosis.
Show evidence (1 reference)
url:https://pmc.ncbi.nlm.nih.gov/articles/PMC6927439/ SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Angiogram confirming no retrograde flow into the web and no flow-limiting stenosis."
A single stenting case documented disappearance of retrograde pouch filling after deployment, alongside OCT-confirmed stent apposition. It supports the local flow effect, not comparative efficacy or universal prevention of embolization.
Target Phenotypes: Ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Ischemic stroke (HP:0002140). HP:0002140 is a phenotype from the Human Phenotype Ontology.
Show evidence (3 references)
PMID:40776764 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"CAS was undertaken in 48 patients (67.6%) and CEA in 23 (32.4%). One patient (1.41%) experienced a perioperative stroke, and none experienced a perioperative MI"
Reports procedures and adverse events in the 71-person retrospective cohort.
PMID:40776764 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"no recurrent strokes were observed in patients undergoing CEA, and one recurrent symptomatic stroke occurred in the CAS cohort."
The full-text discussion reports recurrence; the abstract calls it asymptomatic, so no claim about recurrence severity is inferred from the abstract.
PMID:40503762 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"given the small, heterogeneous cohorts and the uncertain natural history of carotid artery web under medical management, these findings should be interpreted with caution until prospective, controlled comparative effectiveness studies are performed."
The meta-analysis combines observational studies; lower recurrence after revascularization does not establish randomized comparative efficacy.
Transcarotid artery revascularization
Action: Endovascular StentingNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Endovascular Stenting (NCIT:C157840). NCIT:C157840 is a clinical intervention from the NCI Thesaurus. NCIT:C157840
Platform: Device
TCAR is a stent-based approach reported for selected symptomatic webs. A 2026 series of 20 revascularized patients used TCAR in 65%, with no ipsilateral recurrent ischemic strokes during a median nine-month follow-up across all approaches. This small uncontrolled series does not establish superiority or long-term safety.
Mechanism Target:
INHIBITS Disturbed carotid flow and stasis — The TCAR stent is intended to exclude the web pouch; the local flow mechanism is extrapolated from conventional carotid stenting.
Show evidence (1 reference)
url:https://pmc.ncbi.nlm.nih.gov/articles/PMC6927439/ SUPPORT INDIRECT PRIMARY RESULT Human Clinical
"Angiogram confirming no retrograde flow into the web and no flow-limiting stenosis."
The flow effect was imaged after conventional carotid stenting. Applying it to TCAR is a mechanism-based extrapolation from its stent component; the TCAR cohort establishes use, not this imaging endpoint.
Target Phenotypes: Ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Ischemic stroke (HP:0002140). HP:0002140 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:42710700 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"TCAR was the most common approach (65%), followed by CAS (20%) and CEA (15%)."
A 20-person single-center retrospective series includes TCAR as an approach, not a randomized comparison.
PMID:42710700 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Over a median follow-up of 9 months (IQR: 6-21), no patients experienced recurrent ischemic stroke in the treated vascular territory, suggesting potential effectiveness of revascularization in preventing recurrence in selected patients with carotid webs."
Short uncontrolled follow-up limits conclusions; this Brown series may overlap earlier reports from the same center.
Mechanical thrombectomy for acute ischemic stroke
Action: Thrombectomy for StrokeNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Thrombectomy for Stroke (NCIT:C191635). NCIT:C191635 is a clinical intervention from the NCI Thesaurus. NCIT:C191635
Platform: Surgery
Endovascular thrombectomy treats an eligible acute intracranial occlusion associated with a carotid web. It restores downstream patency but leaves the carotid lesion in place, so it does not establish a secondary-prevention strategy.
Target Phenotypes: Ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Ischemic stroke (HP:0002140). HP:0002140 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42710700 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Fifteen (75%) underwent mechanical thrombectomy and 8 (40%) received IV thrombolysis."
Documents acute therapies in the selected 20-person symptomatic cohort, without establishing web-specific comparative efficacy.
Intravenous thrombolysis for acute ischemic stroke
Action: Thrombolytic TherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Thrombolytic Therapy (NCIT:C15338). NCIT:C15338 is a clinical intervention from the NCI Thesaurus. NCIT:C15338
Platform: Other
Intravenous thrombolysis is another acute reperfusion treatment used in eligible web-associated strokes. It addresses the acute thrombotic occlusion and does not remove the intimal shelf.
Target Phenotypes: Ischemic stroke HP:0002140 Human Phenotype Ontology (HP) Relation: this treatment targets this phenotype This treatment targets Ischemic stroke (HP:0002140). HP:0002140 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:42710700 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Fifteen (75%) underwent mechanical thrombectomy and 8 (40%) received IV thrombolysis."
The series documents use of intravenous thrombolysis; it does not determine eligibility or comparative benefit.
🔬

Diagnosis

2
Multiplanar carotid vascular imaging and etiologic stroke assessment
CTA with axial and oblique sagittal reconstructions identifies the shelf and septum. Complementary ultrasound or vessel-wall MRI can resolve uncertainty; DSA is useful for unresolved diagnosis or intervention. The recommendation to use two modalities is an expert-review proposal, not a validated universal criterion. A web found ipsilateral to stroke still requires evaluation for competing causes.
Diagnostic Procedure NCIT:C18020 NCI Thesaurus (NCIT)
Show evidence (3 references)
PMID:26228877 SUPPORT DIRECT BACKGROUND Human Clinical
"A carotid web was defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation on oblique sagittal section CTA that was seen as a septum on axial CTA."
The operational imaging definition requires the shelf on oblique sagittal reconstruction and septum on axial images.
PMID:40494576 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"At the moment, the most reasonable suggestion is to use at least two different techniques to confirm the diagnosis of carotid web (e.g., CTA and MRA, or US and CTA), leaving DSA for unsolved questions and implementing the use of VW-MRI for the differential diagnosis."
The authors explicitly frame concordant imaging as a suggestion.
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Competing stroke mechanisms were identified in 15% of patients."
A structural web does not exclude another stroke mechanism.
Distinguishing web, dissection, plaque and superimposed thrombus
A smooth intimal shelf must be distinguished from dissection, noncalcified plaque and thrombus. Repeat or complementary imaging may reveal a web masked by adherent clot. Coexisting atherosclerosis is possible.
Show evidence (3 references)
PMID:40494576 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"The primary differential diagnoses for a carotid web include arterial dissection, non-calcified atherosclerotic plaques, and intraluminal thrombus."
Lists the main imaging alternatives.
PMID:40873957 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"In two cases, superimposed thrombi led to initial misdiagnoses such as soft plaque or dissection."
Direct clinical-pathology correlation documents a diagnostic pitfall.
PMID:41885481 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Notably, concurrent atheromatous changes were noted in 6 patients."
The larger pathologically confirmed series establishes that atherosclerosis can coexist.
🩻

Imaging Findings

4
Posterior carotid-bulb shelf and axial septum
CTA shows the shelf on oblique sagittal reconstructions and a septum on axial images. Small protrusions lacking an axial septum were excluded from the classic imaging definition.
Ct
Show evidence (2 references)
PMID:26228877 SUPPORT DIRECT BACKGROUND Human Clinical
"A carotid web was defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation on oblique sagittal section CTA that was seen as a septum on axial CTA."
The operational imaging definition requires the shelf on oblique sagittal reconstruction and septum on axial images.
PMID:26228877 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"In contrast to carotid webs, these lesions were smaller and not seen on the axial sections"
Distinguishes small protruding lesions from the study definition of a web.
Delayed contrast washout in the web pouch
Catheter angiography can show contrast retained distal to the shelf in the late venous phase, consistent with local stasis.
Angiography
Show evidence (1 reference)
PMID:40494576 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"During the late venous phase, contrast agent retention is commonly observed at the distal end of the carotid web."
A dynamic imaging correlate of slow washout.
Sonographic intraluminal shelf
A thin shelf projects into the lumen; specialized microvascular imaging may show a triangular endoluminal defect. The 299-person retrospective ultrasound study selected patients with web or web-plus-plaque and lacked a plaque-only comparison, limiting diagnostic generalization.
Ultrasound
Show evidence (1 reference)
DOI:10.1186/s13244-024-01650-7 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"A thin triangular endoluminal defect is identified as a typical feature of the web on superb microvascular imaging"
A primary multimodal imaging study documents morphology, not a universally validated screening threshold.
Silent ipsilateral cerebral infarctions
Prior cortical or cortico-subcortical infarcts can be visible without a corresponding clinical stroke history. In the 92-person cohort, only seven patients had ipsilateral silent infarcts; their association with recurrence requires caution.
Mri
Show evidence (2 references)
PMID:34102760 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"SCI ipsilateral to the index CIE were found in seven patients (7.6%)"
Reports the small subgroup in which recurrence association was studied.
PMID:34102760 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All SCIs were cortical or cortico-subcortical lesions."
Documents the imaging distribution.
📈

Progression

3
Incidentally detected asymptomatic web
Some webs are detected without an attributable ischemic event, including contralateral lesions. The optimal surveillance schedule and primary-prevention treatment remain uncertain.
Show evidence (1 reference)
PMID:40494576 SUPPORT DIRECT REVIEW SYNTHESIS Human Clinical
"Another unresolved issue is the need for treatment for an asymptomatic, incidentally found carotid web."
The review distinguishes incidental disease from symptomatic secondary prevention.
Early recurrence after a symptomatic event
In a single-center thrombectomy cohort, all recurrent events occurred within 48 hours of the index stroke. The small event count and restricted cohort limit generalization.
Show evidence (2 references)
PMID:39215397 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"11% (3/27) of patients with ipsilateral carotid artery webs experienced recurrent ischemic stroke and LVO."
Three early recurrences occurred among 27 web patients in a single-center anterior-circulation thrombectomy cohort. This estimate does not apply to all incidentally detected webs.
PMID:39215397 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"All recurrent ischemic stroke and large vessel occlusion occurred within 48 h after the index stroke."
Reports timing of the recurrent events.
Longer-term recurrent ischemic risk
Symptomatic cohorts show ongoing recurrence risk despite medical treatment. Stroke-only estimates and combined stroke/TIA estimates must be kept separate, and neither defines risk in an incidental asymptomatic web.
Show evidence (2 references)
PMID:34102760 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Under medical treatment alone, the annual recurrent CIE rate was 6.9%, and the cumulative rate was 4.4% at 30-day, 10.8% at 1-year, 19.8% at 2-year, 23.2% at 3-year, and 27.3% at 5-year."
These Kaplan-Meier estimates combine stroke and TIA in a 92-person Afro-Caribbean symptomatic cohort; nonrandom treatment selection and adherence uncertainty limit comparisons.
PMID:33970205 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"During 2 years of follow-up, 5 of 30 patients (17%) with CW had a recurrent stroke compared with 5 of 168 patients (3%) without CW (adjusted hazard ratio, 4.9; 95% CI, 1.4-18.1)."
The MR CLEAN-derived comparison involved anterior-circulation LVO patients; 28/30 web patients received medical management. This endpoint is recurrent stroke, whereas the other cohort combined stroke and TIA.
🌍

Epidemiology

2
Demographics of an adjudicated symptomatic registry
The French CAROWEB cohort was female-predominant and included multiple ancestry groups. Referral, imaging and symptomatic selection constrain interpretation; ancestry is not a demonstrated causal genetic factor.
Show evidence (1 reference)
PMID:37724713 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Between June 2019 and December 2021, 244 cases were submitted by 14 centers, 42 rejected, and 202 included (IS, 91.6%; TIA, 7.9%; retinal infarction, 0.5%; mean age, 50.8 ± 12.2 years; female, 62.9%; Caucasian, 47.5%; Afro-Caribbean, 20.3%)."
The adjudicated French registry selected symptomatic cases; these proportions are not penetrance or population prevalence.
Hospital-based detection prevalence
A 2015 retrospective suspected-stroke imaging series detected webs in 7/576 patients (1.2%). This was a hospital convenience sample with CTA and follow-up brain MRI, not population screening.
Show evidence (1 reference)
PMID:26228877 SUPPORT DIRECT PRIMARY RESULT Human Clinical
"Thus, the prevalence of carotid webs in a hospital-based series is estimated at 1.2% (95% CI, 0.4%–2.5%)."
The full methods identify a suspected-stroke CTA/MRI convenience sample.
🔬

Clinical Trials

6
NCT04431609 NOT_APPLICABLE UNKNOWN
CAROWEB is an observational French cohort of symptomatic carotid webs collecting clinical, imaging, management and recurrence data. The published 202-person analysis describes selected symptomatic cases.
Show evidence (1 reference)
clinicaltrials:NCT04431609 SUPPORT DIRECT BACKGROUND Other
"We assume that the implementation of a multicentric cohort would allow a comprehensive analysis of the carotid web condition."
Registry protocol describes the study purpose, not an observed result.
NCT05475080 NOT_APPLICABLE UNKNOWN
Prospective observational registry comparing recurrence by preventive treatment and exploring clinical, radiologic and optional genetic associations. Genetic polymorphism detection is a study aim, not an established disease mechanism.
Show evidence (1 reference)
clinicaltrials:NCT05475080 SUPPORT DIRECT BACKGROUND Other
"To detect genetic polymorphisms associated with the presence of CW in stroke patients."
Registry protocol describes the study purpose, not an observed result.
NCT06336083 NOT_APPLICABLE RECRUITING
Family-WEB is a phase-not-applicable interventional ultrasound screening study of relatives. Its registry purpose does not establish familial inheritance or a causal gene.
Show evidence (1 reference)
clinicaltrials:NCT06336083 SUPPORT DIRECT BACKGROUND Other
"There is no evidence of familial forms of carotid web. The aim of this study is to determine the prevalence of carotid web among relatives of patient with carotid web using carotid doppler ultrasound."
Registry protocol describes the study purpose, not an observed result.
NCT07495241 NOT_APPLICABLE RECRUITING
CaWY is an observational population-based duplex survey of people aged 15-25 years. Planned recruitment is not an observed prevalence result.
Show evidence (1 reference)
clinicaltrials:NCT07495241 SUPPORT DIRECT BACKGROUND Other
"The CaWY study is a cross-sectional, multicenter, population-based sonographic survey with blinded central image adjudication, reported in accordance with STROBE guidelines for cross-sectional studies, aimed at estimating the prevalence of CaW detected by duplex sonography in the general..."
Registry protocol describes the study purpose, not an observed result.
NCT06058507 NOT_APPLICABLE COMPLETED
Completed observational radiologic study of web detection, classification and association with ischemic stroke. Registry completion does not by itself provide comparative treatment results.
Show evidence (1 reference)
clinicaltrials:NCT06058507 SUPPORT DIRECT BACKGROUND Other
"In our research, we aim to increase awareness on this issue by classifying the frequency of carotid webs and their radiological classification; Evaluating the clinical data and vascular risk factors of carotid web cases and determining their relationship with ischemic stroke and determining the..."
Registry protocol describes the study purpose, not an observed result.
NCT04442074 NOT_APPLICABLE UNKNOWN
Observational study of Doppler ultrasound characteristics of symptomatic carotid diaphragm/web. This is a diagnostic investigation, not a randomized therapeutic trial.
Show evidence (1 reference)
clinicaltrials:NCT04442074 SUPPORT DIRECT BACKGROUND Other
"This descriptive study of the diagnostic contribution of the echo-doppler for a carotid diaphragm"
Registry protocol describes the study purpose, not an observed result.
{ }

Source YAML

click to show 
name: Carotid web
creation_date: '2026-05-05T20:46:40Z'
category: Complex
description: >-
  Carotid web is a non-atherosclerotic intimal shelf projecting into the carotid bulb or proximal internal carotid
  artery, most often from the posterior wall. Histology supports an intimal fibromuscular dysplasia phenotype, although
  its origin is incompletely understood. Disturbed flow and stasis in the web pouch favor local thrombosis and downstream
  artery-to-artery embolism. Webs may be incidental or associated with ipsilateral ischemic stroke, transient ischemic
  attack, or retinal ischemia; a severe flow-limiting stenosis is not required.
disease_term:
  preferred_term: carotid web
  term:
    id: MONDO:0979323
    label: carotid web
synonyms:
- Carotid artery web
- Carotid bulb web
- Carotid diaphragm
parents:
- Vasculopathy
- Cerebrovascular Disease
definitions:
- name: Multiplanar CTA definition of carotid web
  definition_type: CASE_DEFINITION
  description: A thin shelf-like filling defect of the posterior carotid bulb seen on oblique sagittal CTA and as a septum on axial images. The imaging lesion may be present without a clinical ischemic event.
  scope: Structural imaging definition; attribution of a stroke requires clinical and etiologic assessment.
  evidence:
  - &id002
    reference: PMID:26228877
    reference_title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: A carotid web was defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation on oblique sagittal section CTA that was seen as a septum on axial CTA.
    explanation: The operational imaging definition requires the shelf on oblique sagittal reconstruction and septum on axial images.
pathophysiology:
- name: Intimal shelf lesion of the carotid bulb
  description: Eccentric fibrous and myxoid intimal tissue forms a shelf projecting into the arterial lumen. Smooth-muscle-like spindle cells are embedded in extracellular matrix; the lesion differs from a lipid-rich atheroma.
  biological_scale: TISSUE
  mechanism_confidence: ESTABLISHED
  evidence:
  - reference: PMID:40873957
    reference_title: Histopathologic evidence of intimal hyperplasia in carotid artery webs associated with stroke.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Histopathologic analysis consistently demonstrated fibrovascular tissue with intimal fibroid hyperplasia and myxoid degeneration, without lipid-rich plaques or inflammatory infiltrates.
    explanation: Three surgically selected symptomatic patients had non-atheromatous intimal lesions; the series does not exclude coexisting atherosclerosis in other patients.
  - reference: PMID:40494576
    reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: The common histological feature of the carotid web is eccentric intimal hyperplasia, characterized by spindle cells (consistent with migrated vascular smooth muscle cells) intermingled within an abundant loose extracellular matrix.
    explanation: Summarizes the cellular and matrix composition of resected webs, not an experimentally established developmental origin.
  cell_types:
  - preferred_term: vascular associated smooth muscle cell
    term:
      id: CL:0000359
      label: vascular associated smooth muscle cell
  locations:
  - preferred_term: internal carotid artery
    term:
      id: UBERON:0001532
      label: internal carotid artery
  - preferred_term: carotid sinus
    term:
      id: UBERON:0003708
      label: carotid sinus
  downstream:
  - target: Disturbed carotid flow and stasis
    description: The intraluminal shelf produces a recirculation pouch with slow washout.
    causal_link_type: DIRECT
    evidence:
    - reference: DOI:10.1038/s41598-024-60666-7
      reference_title: Subjects with carotid webs demonstrate pro-thrombotic hemodynamics compared to subjects with carotid atherosclerosis
      supports: SUPPORT
      evidence_source: COMPUTATIONAL
      quote_role: PRIMARY_RESULT
      directness: DIRECT
      snippet: Patients with CaW had significantly larger regions containing low shear rate, high OSI, low velocity, and flow stasis in comparison to subjects with mild atherosclerosis or normal bifurcations.
      explanation: Patient-specific CFD assessed flow surrogates in 13 web bifurcations, seven atherosclerotic bifurcations and six contralateral normal bifurcations; it did not measure platelet activation or prospective stroke risk.
- name: Disturbed carotid flow and stasis
  description: The web geometry produces local flow separation, recirculation, low velocity and prolonged residence time. These abnormalities can occur with modest luminal narrowing.
  biological_scale: TISSUE
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: DOI:10.1038/s41598-024-60666-7
    reference_title: Subjects with carotid webs demonstrate pro-thrombotic hemodynamics compared to subjects with carotid atherosclerosis
    supports: SUPPORT
    evidence_source: COMPUTATIONAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Patients with CaW had significantly larger regions containing low shear rate, high OSI, low velocity, and flow stasis in comparison to subjects with mild atherosclerosis or normal bifurcations.
    explanation: Patient-specific CFD assessed flow surrogates in 13 web bifurcations, seven atherosclerotic bifurcations and six contralateral normal bifurcations; it did not measure platelet activation or prospective stroke risk.
  locations:
  - preferred_term: internal carotid artery
    term:
      id: UBERON:0001532
      label: internal carotid artery
  notes: The CFD study assumed rigid walls and Newtonian blood, used a small symptomatic sample, and included older atherosclerotic comparators. Six normal geometries came from contralateral arteries of web patients. Hemodynamic thresholds were exploratory; modeled stasis is not a direct assay of coagulation or a validated individual stroke predictor.
  downstream:
  - target: Web-associated mural thrombosis
    description: Slow washout favors local accumulation of thrombotic material.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:40494576
      reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: REVIEW_SYNTHESIS
      directness: DIRECT
      snippet: It is proposed that the presence of a carotid web leads to thrombogenic hemodynamic changes downstream, which may facilitate thrombus formation and subsequent embolization, resulting in stroke
      explanation: The flow-to-thrombus-to-embolus hypothesis is supported by imaging and pathology, but not by a randomized mechanistic experiment.
- name: Web-associated mural thrombosis
  description: Thrombus forms in or adheres to the pouch of the web. Serial imaging can show its appearance and resolution, and resected specimens can contain adherent mural thrombus.
  biological_scale: TISSUE
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:26228877
    reference_title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Specimens from another case contained a thick fibrous intimal cushion with a recent mural thrombus
    explanation: Direct histology documents thrombus associated with the intimal lesion.
  - reference: PMID:26228877
    reference_title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: In 2 patients, thrombus-like material was seen at the site of the carotid web, with changing morphology on serial CTAs, despite concurrent antiplatelet therapy.
    explanation: Serial imaging supports dynamic local thrombus formation, without establishing treatment efficacy.
  biological_processes:
  - preferred_term: blood coagulation
    term:
      id: GO:0007596
      label: blood coagulation
    modifier: INCREASED
  locations:
  - preferred_term: internal carotid artery
    term:
      id: UBERON:0001532
      label: internal carotid artery
  downstream:
  - target: Artery-to-artery embolization
    description: Fragments of web-associated thrombus can be carried into downstream cerebral or retinal arteries.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34102760
      reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: BACKGROUND
      directness: DIRECT
      snippet: The widely accepted mechanism of cerebral ischemic events (CIE) is an artery-to-artery embolism through blood stasis rostral to CaW, thrombus formation and clot fragmentation scattered by the blood flow
      explanation: The cohort introduction summarizes the proposed embolic pathway; this is background mechanistic evidence.
- name: Artery-to-artery embolization
  description: Detachment and transport of web-associated thrombus can occlude downstream vessels. Ischemic manifestations depend on the affected vascular territory and whether perfusion is restored before infarction.
  biological_scale: TISSUE
  mechanism_confidence: PROVISIONAL
  evidence:
  - reference: PMID:34102760
    reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: The widely accepted mechanism of cerebral ischemic events (CIE) is an artery-to-artery embolism through blood stasis rostral to CaW, thrombus formation and clot fragmentation scattered by the blood flow
    explanation: The cohort introduction summarizes the proposed embolic pathway; this is background mechanistic evidence.
  downstream:
  - target: Embolic ischemic stroke
    description: Persistent downstream occlusion can cause cerebral infarction.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34102760
      reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: BACKGROUND
      directness: DIRECT
      snippet: The widely accepted mechanism of cerebral ischemic events (CIE) is an artery-to-artery embolism through blood stasis rostral to CaW, thrombus formation and clot fragmentation scattered by the blood flow
      explanation: The cohort introduction summarizes the proposed embolic pathway; this is background mechanistic evidence.
  - target: Recurrent ischemic stroke
    description: A persistent thrombogenic lesion can produce further ipsilateral embolic events.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:34102760
      reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: BACKGROUND
      directness: DIRECT
      snippet: The widely accepted mechanism of cerebral ischemic events (CIE) is an artery-to-artery embolism through blood stasis rostral to CaW, thrombus formation and clot fragmentation scattered by the blood flow
      explanation: The cohort introduction summarizes the proposed embolic pathway; this is background mechanistic evidence.
    intermediate_mechanisms:
    - renewed local thrombus formation and embolization
  - target: Transient ischemic attack
    description: Transient downstream ischemia can resolve without an established infarct.
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:34102760
      reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: BACKGROUND
      directness: DIRECT
      snippet: The widely accepted mechanism of cerebral ischemic events (CIE) is an artery-to-artery embolism through blood stasis rostral to CaW, thrombus formation and clot fragmentation scattered by the blood flow
      explanation: The cohort introduction summarizes the proposed embolic pathway; this is background mechanistic evidence.
  - target: Hemiparesis
    description: Ischemic injury involving motor pathways can cause unilateral weakness.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:40776764
      reference_title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      directness: INDIRECT
      snippet: The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation.
      explanation: Symptom spectrum in a selected revascularization cohort; the motor-pathway mediation is inferred.
    intermediate_mechanisms:
    - cerebral ischemic injury affecting motor pathways
  - target: Aphasia
    description: Dominant-hemisphere ischemia can impair language.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:40776764
      reference_title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      directness: INDIRECT
      snippet: The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation.
      explanation: Symptom spectrum in a selected revascularization cohort; language-network mediation is inferred.
    intermediate_mechanisms:
    - cerebral ischemic injury affecting language networks
  - target: Central retinal artery occlusion
    description: An embolus entering the retinal arterial circulation can produce retinal infarction.
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    evidence:
    - reference: PMID:34102760
      reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      directness: DIRECT
      snippet: At inclusion, 13 patients experienced a TIA as first-ever CIE and two patients suffered from a central retina artery infarction without any recent lesion on admission MRI.
      explanation: Two retinal arterial infarctions were observed among 92 selected symptomatic patients; this is not a general-population frequency.
    intermediate_mechanisms:
    - embolization into the retinal arterial circulation
phenotypes:
- name: Embolic ischemic stroke
  category: Neurologic
  description: Ipsilateral ischemic stroke, often including large-vessel occlusion, is a major symptomatic presentation. The lesion may also be incidental, so stroke is not required to diagnose a web.
  phenotype_term:
    preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
  evidence:
  - reference: PMID:37724713
    reference_title: 'Clinical, imaging, and management features of symptomatic carotid web: Insight from CAROWEB registry.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Between June 2019 and December 2021, 244 cases were submitted by 14 centers, 42 rejected, and 202 included (IS, 91.6%; TIA, 7.9%; retinal infarction, 0.5%; mean age, 50.8 ± 12.2 years; female, 62.9%; Caucasian, 47.5%; Afro-Caribbean, 20.3%).
    explanation: The adjudicated French registry selected symptomatic cases; these proportions are not penetrance or population prevalence.
- name: Recurrent ischemic stroke
  category: Neurologic
  description: Further ipsilateral ischemic events can occur during the initial hospitalization or over subsequent years. Recurrence estimates vary with case selection, antithrombotic treatment and endpoint definition.
  phenotype_term:
    preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
    temporality: RECURRENT
  evidence:
  - reference: PMID:39215397
    reference_title: In-hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: 11% (3/27) of patients with ipsilateral carotid artery webs experienced recurrent ischemic stroke and LVO.
    explanation: Three early recurrences occurred among 27 web patients in a single-center anterior-circulation thrombectomy cohort. This estimate does not apply to all incidentally detected webs.
- name: Transient ischemic attack
  category: Neurologic
  description: Transient focal neurologic dysfunction without a persisting infarct is another symptomatic presentation.
  phenotype_term:
    preferred_term: Transient ischemic attack
    term:
      id: HP:0002326
      label: Transient ischemic attack
  evidence:
  - reference: PMID:37724713
    reference_title: 'Clinical, imaging, and management features of symptomatic carotid web: Insight from CAROWEB registry.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Between June 2019 and December 2021, 244 cases were submitted by 14 centers, 42 rejected, and 202 included (IS, 91.6%; TIA, 7.9%; retinal infarction, 0.5%; mean age, 50.8 ± 12.2 years; female, 62.9%; Caucasian, 47.5%; Afro-Caribbean, 20.3%).
    explanation: The adjudicated French registry selected symptomatic cases; these proportions are not penetrance or population prevalence.
- name: Hemiparesis
  category: Neurologic
  description: Unilateral weakness may accompany carotid-web-associated cerebral ischemia; the distribution depends on the affected brain territory.
  phenotype_term:
    preferred_term: Hemiparesis
    term:
      id: HP:0001269
      label: Hemiparesis
  evidence:
  - reference: PMID:40776764
    reference_title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation.
    explanation: Reports presenting focal deficits in the symptomatic surgical/interventional cohort.
- name: Aphasia
  category: Neurologic
  description: Language dysfunction can be part of the presenting ischemic event.
  phenotype_term:
    preferred_term: Aphasia
    term:
      id: HP:0002381
      label: Aphasia
  evidence:
  - reference: PMID:40776764
    reference_title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: The most common presenting symptoms were hemibody numbness/weakness, aphasia, and gaze deviation.
    explanation: Documents aphasia among common presenting symptoms in the cohort.
- name: Central retinal artery occlusion
  category: Ophthalmologic
  description: Retinal arterial infarction is an uncommon reported ischemic presentation.
  phenotype_term:
    preferred_term: Central retinal artery occlusion
    term:
      id: HP:0025342
      label: Central retinal artery occlusion
  evidence:
  - reference: PMID:34102760
    reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: At inclusion, 13 patients experienced a TIA as first-ever CIE and two patients suffered from a central retina artery infarction without any recent lesion on admission MRI.
    explanation: Two retinal arterial infarctions were observed among 92 selected symptomatic patients; this is not a general-population frequency.
progression:
- phase: Incidentally detected asymptomatic web
  notes: Some webs are detected without an attributable ischemic event, including contralateral lesions. The optimal surveillance schedule and primary-prevention treatment remain uncertain.
  evidence:
  - reference: PMID:40494576
    reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: Another unresolved issue is the need for treatment for an asymptomatic, incidentally found carotid web.
    explanation: The review distinguishes incidental disease from symptomatic secondary prevention.
- phase: Early recurrence after a symptomatic event
  notes: In a single-center thrombectomy cohort, all recurrent events occurred within 48 hours of the index stroke. The small event count and restricted cohort limit generalization.
  evidence:
  - reference: PMID:39215397
    reference_title: In-hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: 11% (3/27) of patients with ipsilateral carotid artery webs experienced recurrent ischemic stroke and LVO.
    explanation: Three early recurrences occurred among 27 web patients in a single-center anterior-circulation thrombectomy cohort. This estimate does not apply to all incidentally detected webs.
  - reference: PMID:39215397
    reference_title: In-hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: All recurrent ischemic stroke and large vessel occlusion occurred within 48 h after the index stroke.
    explanation: Reports timing of the recurrent events.
- phase: Longer-term recurrent ischemic risk
  notes: Symptomatic cohorts show ongoing recurrence risk despite medical treatment. Stroke-only estimates and combined stroke/TIA estimates must be kept separate, and neither defines risk in an incidental asymptomatic web.
  evidence:
  - reference: PMID:34102760
    reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Under medical treatment alone, the annual recurrent CIE rate was 6.9%, and the cumulative rate was 4.4% at 30-day, 10.8% at 1-year, 19.8% at 2-year, 23.2% at 3-year, and 27.3% at 5-year.
    explanation: These Kaplan-Meier estimates combine stroke and TIA in a 92-person Afro-Caribbean symptomatic cohort; nonrandom treatment selection and adherence uncertainty limit comparisons.
  - reference: PMID:33970205
    reference_title: Assessment of Recurrent Stroke Risk in Patients With a Carotid Web.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: During 2 years of follow-up, 5 of 30 patients (17%) with CW had a recurrent stroke compared with 5 of 168 patients (3%) without CW (adjusted hazard ratio, 4.9; 95% CI, 1.4-18.1).
    explanation: The MR CLEAN-derived comparison involved anterior-circulation LVO patients; 28/30 web patients received medical management. This endpoint is recurrent stroke, whereas the other cohort combined stroke and TIA.
biochemical: []
genetic: []
environmental: []
epidemiology:
- name: Demographics of an adjudicated symptomatic registry
  description: The French CAROWEB cohort was female-predominant and included multiple ancestry groups. Referral, imaging and symptomatic selection constrain interpretation; ancestry is not a demonstrated causal genetic factor.
  evidence:
  - reference: PMID:37724713
    reference_title: 'Clinical, imaging, and management features of symptomatic carotid web: Insight from CAROWEB registry.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Between June 2019 and December 2021, 244 cases were submitted by 14 centers, 42 rejected, and 202 included (IS, 91.6%; TIA, 7.9%; retinal infarction, 0.5%; mean age, 50.8 ± 12.2 years; female, 62.9%; Caucasian, 47.5%; Afro-Caribbean, 20.3%).
    explanation: The adjudicated French registry selected symptomatic cases; these proportions are not penetrance or population prevalence.
- name: Hospital-based detection prevalence
  description: A 2015 retrospective suspected-stroke imaging series detected webs in 7/576 patients (1.2%). This was a hospital convenience sample with CTA and follow-up brain MRI, not population screening.
  evidence:
  - reference: PMID:26228877
    reference_title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Thus, the prevalence of carotid webs in a hospital-based series is estimated at 1.2% (95% CI, 0.4%–2.5%).
    explanation: The full methods identify a suspected-stroke CTA/MRI convenience sample.
treatments:
- name: Antithrombotic medical therapy after symptomatic ischemia
  description: Antiplatelet therapy is commonly used after symptomatic events, including alongside revascularization. Anticoagulation has also been used in selected patients or for other indications. The optimal agent, combination and duration for the web itself are not established; recurrence can occur on therapy.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: acetylsalicylic acid
      term:
        id: CHEBI:15365
        label: acetylsalicylic acid
    - preferred_term: Vitamin K Antagonist
      term:
        id: NCIT:C173064
        label: Vitamin K Antagonist
  target_phenotypes:
  - preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
  evidence:
  - reference: PMID:40494576
    reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: Treatment options in symptomatic cases include medical therapy (single or dual antiplatelets) or interventional approach (surgery or stenting), but there are no randomized controlled trials about therapy.
    explanation: Review synthesis documents available approaches and the absence of randomized comparative treatment evidence.
  - reference: PMID:34102760
    reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: All patients treated with carotid surgery or stenting received long-term antithrombotic therapy with aspirin (n=21) or vitamin K antagonist (n=2) that was ongoing at the end of follow-up.
    explanation: Documents agents used in this cohort; it does not prescribe a universal regimen.
  - reference: PMID:39215397
    reference_title: In-hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: the benefit of immediate dual antiplatelet or anticoagulation therapy remains unclear, particularly in medium to large strokes where there is an elevated risk of hemorrhage
    explanation: The discussion highlights uncertainty about escalation of antithrombotic treatment, not a demonstrated benefit.
  therapeutic_modality: SMALL_MOLECULE
- name: Carotid endarterectomy
  description: Selected symptomatic patients undergo surgical excision of the web, removing a local embolic source and permitting histological examination. Retrospective series report low recurrence but have no randomized medical control; cranial-nerve injury is a procedural risk.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: Carotid Endarterectomy
    term:
      id: NCIT:C157807
      label: Carotid Endarterectomy
  target_mechanisms:
  - target: Artery-to-artery embolization
    treatment_effect: INHIBITS
    description: Excision removes the structural source from which local thrombi can embolize.
    evidence:
    - reference: PMID:41885481
      reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      directness: DIRECT
      snippet: Among 39 patients with symptomatic carotid web, 34 underwent CEA with histopathological confirmation of the diagnosis, characterized by focal eccentric intimal fibromyxoid tissue, fibromuscular dysplasia, hyperplasia, or thickening.
      explanation: Surgery removed the lesion and supplied tissue for histological diagnosis in this selected retrospective cohort.
  evidence:
  - reference: PMID:41885481
    reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Among 39 patients with symptomatic carotid web, 34 underwent CEA with histopathological confirmation of the diagnosis, characterized by focal eccentric intimal fibromyxoid tissue, fibromuscular dysplasia, hyperplasia, or thickening.
    explanation: Surgery removed the lesion and supplied tissue for histological diagnosis in this selected retrospective cohort.
  - reference: PMID:41885481
    reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: 'At a median follow-up of 29 months, no patients experienced recurrent stroke (95% CI: 0%-10%), and the median modified Rankin Scale score was 1 (0-1).'
    explanation: The confidence interval and lack of randomized controls prevent interpreting zero observed recurrences as zero future risk.
  - reference: PMID:41885481
    reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Two patients experienced transient, minor cranial nerves injuries (hypoglossal nerve and marginal mandibular branch) after CEA.
    explanation: Documents procedural morbidity.
  - &id001
    reference: PMID:40503762
    reference_title: 'Carotid Revascularization Versus Medical Management for Ischemic Stroke with Ipsilateral Carotid Web: A Systematic Review and Meta-Analysis.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: given the small, heterogeneous cohorts and the uncertain natural history of carotid artery web under medical management, these findings should be interpreted with caution until prospective, controlled comparative effectiveness studies are performed.
    explanation: The meta-analysis combines observational studies; lower recurrence after revascularization does not establish randomized comparative efficacy.
- name: Carotid artery stenting
  description: Stenting across the web is used to exclude the thrombogenic pouch in selected symptomatic patients. The 71-person multicenter series included 48 stenting and 23 endarterectomy procedures, with one perioperative stroke overall and one recurrent stroke in the stenting group. Procedure selection was not randomized and there was no medical-only control.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: Endovascular Stenting
    term:
      id: NCIT:C157840
      label: Endovascular Stenting
  target_phenotypes:
  - preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
  evidence:
  - reference: PMID:40776764
    reference_title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: CAS was undertaken in 48 patients (67.6%) and CEA in 23 (32.4%). One patient (1.41%) experienced a perioperative stroke, and none experienced a perioperative MI
    explanation: Reports procedures and adverse events in the 71-person retrospective cohort.
  - reference: PMID:40776764
    reference_title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: no recurrent strokes were observed in patients undergoing CEA, and one recurrent symptomatic stroke occurred in the CAS cohort.
    explanation: The full-text discussion reports recurrence; the abstract calls it asymptomatic, so no claim about recurrence severity is inferred from the abstract.
  - *id001
  target_mechanisms:
  - target: Disturbed carotid flow and stasis
    treatment_effect: INHIBITS
    description: Stent apposition can exclude the web pouch from retrograde filling, reducing the local flow disturbance that promotes thrombosis.
    evidence:
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC6927439/
      reference_title: Optical coherence tomography as an adjunct during carotid artery stenting for carotid web - PMC
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      directness: DIRECT
      snippet: Angiogram confirming no retrograde flow into the web and no flow-limiting stenosis.
      explanation: A single stenting case documented disappearance of retrograde pouch filling after deployment, alongside OCT-confirmed stent apposition. It supports the local flow effect, not comparative efficacy or universal prevention of embolization.
- name: Transcarotid artery revascularization
  description: TCAR is a stent-based approach reported for selected symptomatic webs. A 2026 series of 20 revascularized patients used TCAR in 65%, with no ipsilateral recurrent ischemic strokes during a median nine-month follow-up across all approaches. This small uncontrolled series does not establish superiority or long-term safety.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: Endovascular Stenting
    term:
      id: NCIT:C157840
      label: Endovascular Stenting
  target_phenotypes:
  - preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
  evidence:
  - reference: PMID:42710700
    reference_title: Carotid revascularization is associated with reduced recurrence in symptomatic carotid web.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: TCAR was the most common approach (65%), followed by CAS (20%) and CEA (15%).
    explanation: A 20-person single-center retrospective series includes TCAR as an approach, not a randomized comparison.
  - reference: PMID:42710700
    reference_title: Carotid revascularization is associated with reduced recurrence in symptomatic carotid web.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: 'Over a median follow-up of 9 months (IQR: 6-21), no patients experienced recurrent ischemic stroke in the treated vascular territory, suggesting potential effectiveness of revascularization in preventing recurrence in selected patients with carotid webs.'
    explanation: Short uncontrolled follow-up limits conclusions; this Brown series may overlap earlier reports from the same center.
  target_mechanisms:
  - target: Disturbed carotid flow and stasis
    treatment_effect: INHIBITS
    description: The TCAR stent is intended to exclude the web pouch; the local flow mechanism is extrapolated from conventional carotid stenting.
    evidence:
    - reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC6927439/
      reference_title: Optical coherence tomography as an adjunct during carotid artery stenting for carotid web - PMC
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      quote_role: PRIMARY_RESULT
      directness: INDIRECT
      snippet: Angiogram confirming no retrograde flow into the web and no flow-limiting stenosis.
      explanation: The flow effect was imaged after conventional carotid stenting. Applying it to TCAR is a mechanism-based extrapolation from its stent component; the TCAR cohort establishes use, not this imaging endpoint.
  notes: NCIT:C157840 captures the endovascular stent component. The OAK query runoak -i ols:ncit search 'l~transcarotid' 'l~TCAR' returned no matches on 2026-10-04; the term does not encode the transcarotid access or flow-reversal protection.
- name: Mechanical thrombectomy for acute ischemic stroke
  description: Endovascular thrombectomy treats an eligible acute intracranial occlusion associated with a carotid web. It restores downstream patency but leaves the carotid lesion in place, so it does not establish a secondary-prevention strategy.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: Thrombectomy for Stroke
    term:
      id: NCIT:C191635
      label: Thrombectomy for Stroke
  target_phenotypes:
  - preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
  evidence:
  - reference: PMID:42710700
    reference_title: Carotid revascularization is associated with reduced recurrence in symptomatic carotid web.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Fifteen (75%) underwent mechanical thrombectomy and 8 (40%) received IV thrombolysis.
    explanation: Documents acute therapies in the selected 20-person symptomatic cohort, without establishing web-specific comparative efficacy.
- name: Intravenous thrombolysis for acute ischemic stroke
  description: Intravenous thrombolysis is another acute reperfusion treatment used in eligible web-associated strokes. It addresses the acute thrombotic occlusion and does not remove the intimal shelf.
  treatment_term:
    preferred_term: Thrombolytic Therapy
    term:
      id: NCIT:C15338
      label: Thrombolytic Therapy
  target_phenotypes:
  - preferred_term: Ischemic stroke
    term:
      id: HP:0002140
      label: Ischemic stroke
  evidence:
  - reference: PMID:42710700
    reference_title: Carotid revascularization is associated with reduced recurrence in symptomatic carotid web.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Fifteen (75%) underwent mechanical thrombectomy and 8 (40%) received IV thrombolysis.
    explanation: The series documents use of intravenous thrombolysis; it does not determine eligibility or comparative benefit.
  therapeutic_modality: OTHER
  notes: The cited series does not specify the intravenous thrombolytic agent.
diagnosis:
- name: Multiplanar carotid vascular imaging and etiologic stroke assessment
  description: CTA with axial and oblique sagittal reconstructions identifies the shelf and septum. Complementary ultrasound or vessel-wall MRI can resolve uncertainty; DSA is useful for unresolved diagnosis or intervention. The recommendation to use two modalities is an expert-review proposal, not a validated universal criterion. A web found ipsilateral to stroke still requires evaluation for competing causes.
  diagnosis_term:
    preferred_term: Diagnostic Procedure
    term:
      id: NCIT:C18020
      label: Diagnostic Procedure
  evidence:
  - *id002
  - reference: PMID:40494576
    reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: At the moment, the most reasonable suggestion is to use at least two different techniques to confirm the diagnosis of carotid web (e.g., CTA and MRA, or US and CTA), leaving DSA for unsolved questions and implementing the use of VW-MRI for the differential diagnosis.
    explanation: The authors explicitly frame concordant imaging as a suggestion.
  - reference: PMID:41885481
    reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Competing stroke mechanisms were identified in 15% of patients.
    explanation: A structural web does not exclude another stroke mechanism.
- name: Distinguishing web, dissection, plaque and superimposed thrombus
  description: A smooth intimal shelf must be distinguished from dissection, noncalcified plaque and thrombus. Repeat or complementary imaging may reveal a web masked by adherent clot. Coexisting atherosclerosis is possible.
  evidence:
  - reference: PMID:40494576
    reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: The primary differential diagnoses for a carotid web include arterial dissection, non-calcified atherosclerotic plaques, and intraluminal thrombus.
    explanation: Lists the main imaging alternatives.
  - reference: PMID:40873957
    reference_title: Histopathologic evidence of intimal hyperplasia in carotid artery webs associated with stroke.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: In two cases, superimposed thrombi led to initial misdiagnoses such as soft plaque or dissection.
    explanation: Direct clinical-pathology correlation documents a diagnostic pitfall.
  - reference: PMID:41885481
    reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Notably, concurrent atheromatous changes were noted in 6 patients.
    explanation: The larger pathologically confirmed series establishes that atherosclerosis can coexist.
histopathology:
- name: Fibrous and myxoid intimal hyperplasia
  description: Resected webs contain eccentric fibrovascular intimal tissue with myxoid change. Classic lipid-rich atheroma was absent in a three-patient series, but concurrent atheromatous changes occur in other cohorts.
  finding_term:
    preferred_term: Fibrous and myxoid intimal hyperplasia
  evidence:
  - reference: PMID:40873957
    reference_title: Histopathologic evidence of intimal hyperplasia in carotid artery webs associated with stroke.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Histopathologic analysis consistently demonstrated fibrovascular tissue with intimal fibroid hyperplasia and myxoid degeneration, without lipid-rich plaques or inflammatory infiltrates.
    explanation: Three surgically selected symptomatic patients had non-atheromatous intimal lesions; the series does not exclude coexisting atherosclerosis in other patients.
  - reference: PMID:41885481
    reference_title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Notably, concurrent atheromatous changes were noted in 6 patients.
    explanation: Prevents generalizing the absence of plaque in a small case series.
- name: Adherent mural thrombus
  description: Thrombus can adhere to or be embedded in the intimal shelf, supporting a local embolic source; it is not present in every resected specimen.
  finding_term:
    preferred_term: Adherent mural thrombus
  evidence:
  - reference: PMID:26228877
    reference_title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: Specimens from another case contained a thick fibrous intimal cushion with a recent mural thrombus
    explanation: Direct histology documents thrombus associated with the intimal lesion.
notes: This entry concerns the structural carotid web lesion rather than atherosclerotic carotid stenosis. A web can coexist with atherosclerosis, and superimposed thrombus can obscure the underlying shelf. Symptomatic and incidentally detected webs are clinical states, not established molecular subtypes. Cohort demographics do not establish a Mendelian, hormonal, or environmental cause. Recurrence and treatment estimates depend on symptomatic case selection, follow-up, and outcome definitions; primary-prevention benefit for an incidental web is unproven.
imaging_findings:
- name: Posterior carotid-bulb shelf and axial septum
  modality: CT
  description: CTA shows the shelf on oblique sagittal reconstructions and a septum on axial images. Small protrusions lacking an axial septum were excluded from the classic imaging definition.
  evidence:
  - *id002
  - reference: PMID:26228877
    reference_title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: In contrast to carotid webs, these lesions were smaller and not seen on the axial sections
    explanation: Distinguishes small protruding lesions from the study definition of a web.
- name: Delayed contrast washout in the web pouch
  modality: ANGIOGRAPHY
  description: Catheter angiography can show contrast retained distal to the shelf in the late venous phase, consistent with local stasis.
  evidence:
  - reference: PMID:40494576
    reference_title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    directness: DIRECT
    snippet: During the late venous phase, contrast agent retention is commonly observed at the distal end of the carotid web.
    explanation: A dynamic imaging correlate of slow washout.
- name: Sonographic intraluminal shelf
  modality: ULTRASOUND
  description: A thin shelf projects into the lumen; specialized microvascular imaging may show a triangular endoluminal defect. The 299-person retrospective ultrasound study selected patients with web or web-plus-plaque and lacked a plaque-only comparison, limiting diagnostic generalization.
  evidence:
  - reference: DOI:10.1186/s13244-024-01650-7
    reference_title: 'The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: A thin triangular endoluminal defect is identified as a typical feature of the web on superb microvascular imaging
    explanation: A primary multimodal imaging study documents morphology, not a universally validated screening threshold.
- name: Silent ipsilateral cerebral infarctions
  modality: MRI
  description: Prior cortical or cortico-subcortical infarcts can be visible without a corresponding clinical stroke history. In the 92-person cohort, only seven patients had ipsilateral silent infarcts; their association with recurrence requires caution.
  evidence:
  - reference: PMID:34102760
    reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: SCI ipsilateral to the index CIE were found in seven patients (7.6%)
    explanation: Reports the small subgroup in which recurrence association was studied.
  - reference: PMID:34102760
    reference_title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: PRIMARY_RESULT
    directness: DIRECT
    snippet: All SCIs were cortical or cortico-subcortical lesions.
    explanation: Documents the imaging distribution.
clinical_trials:
- name: NCT04431609
  phase: NOT_APPLICABLE
  status: UNKNOWN
  description: CAROWEB is an observational French cohort of symptomatic carotid webs collecting clinical, imaging, management and recurrence data. The published 202-person analysis describes selected symptomatic cases.
  evidence:
  - reference: clinicaltrials:NCT04431609
    reference_title: French Cohort of Carotid Web Associated With Cerebral Infarctions
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: We assume that the implementation of a multicentric cohort would allow a comprehensive analysis of the carotid web condition.
    explanation: Registry protocol describes the study purpose, not an observed result.
  notes: ClinicalTrials.gov checked 2026-10-04; last posted update 2023-10-06. UNKNOWN is the current registry status; last known recruitment was RECRUITING.
- name: NCT05475080
  phase: NOT_APPLICABLE
  status: UNKNOWN
  description: Prospective observational registry comparing recurrence by preventive treatment and exploring clinical, radiologic and optional genetic associations. Genetic polymorphism detection is a study aim, not an established disease mechanism.
  evidence:
  - reference: clinicaltrials:NCT05475080
    reference_title: Carotid Web and Stroke Registry. Clinical and Genetic Study. "Registro de Pacientes Con Carotid Web e Ictus. Estudio clínico y genético"
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: To detect genetic polymorphisms associated with the presence of CW in stroke patients.
    explanation: Registry protocol describes the study purpose, not an observed result.
  notes: ClinicalTrials.gov checked 2026-10-04; last posted update 2022-08-01. UNKNOWN is the current registry status; last known recruitment was RECRUITING.
- name: NCT06336083
  phase: NOT_APPLICABLE
  status: RECRUITING
  description: Family-WEB is a phase-not-applicable interventional ultrasound screening study of relatives. Its registry purpose does not establish familial inheritance or a causal gene.
  evidence:
  - reference: clinicaltrials:NCT06336083
    reference_title: 'Family Screening for Internal Carotid Diaphragm Dysplasia (Carotid WEB): a Doppler Ultrasound Study'
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: There is no evidence of familial forms of carotid web. The aim of this study is to determine the prevalence of carotid web among relatives of patient with carotid web using carotid doppler ultrasound.
    explanation: Registry protocol describes the study purpose, not an observed result.
  notes: ClinicalTrials.gov checked 2026-10-04; last posted update 2026-05-12.
- name: NCT07495241
  phase: NOT_APPLICABLE
  status: RECRUITING
  description: CaWY is an observational population-based duplex survey of people aged 15-25 years. Planned recruitment is not an observed prevalence result.
  evidence:
  - reference: clinicaltrials:NCT07495241
    reference_title: 'Prevalence of Carotid Web in Youth Assessed by Duplex Sonography: a Cross-Sectional Study'
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: The CaWY study is a cross-sectional, multicenter, population-based sonographic survey with blinded central image adjudication, reported in accordance with STROBE guidelines for cross-sectional studies, aimed at estimating the prevalence of CaW detected by duplex sonography in the general population aged 15-25 years.
    explanation: Registry protocol describes the study purpose, not an observed result.
  notes: ClinicalTrials.gov checked 2026-10-04; last posted update 2026-03-27.
- name: NCT06058507
  phase: NOT_APPLICABLE
  status: COMPLETED
  description: Completed observational radiologic study of web detection, classification and association with ischemic stroke. Registry completion does not by itself provide comparative treatment results.
  evidence:
  - reference: clinicaltrials:NCT06058507
    reference_title: '"The Incidence of Carotid Web and Its Radiological Classification, Determination of Its Relationship With Ischemic Stroke by Evaluating the Clinical Data and Vascular Risk Factors of Carotid Web Cases"'
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: In our research, we aim to increase awareness on this issue by classifying the frequency of carotid webs and their radiological classification; Evaluating the clinical data and vascular risk factors of carotid web cases and determining their relationship with ischemic stroke and determining the measures that can be taken for future optimal treatment.
    explanation: Registry protocol describes the study purpose, not an observed result.
  notes: ClinicalTrials.gov checked 2026-10-04; last posted update 2023-09-28.
- name: NCT04442074
  phase: NOT_APPLICABLE
  status: UNKNOWN
  description: Observational study of Doppler ultrasound characteristics of symptomatic carotid diaphragm/web. This is a diagnostic investigation, not a randomized therapeutic trial.
  evidence:
  - reference: clinicaltrials:NCT04442074
    reference_title: Characteristics in Doppler Ultrasound of the Carotid Diaphragm Responsible for an Ischemic Stroke
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: BACKGROUND
    directness: DIRECT
    snippet: This descriptive study of the diagnostic contribution of the echo-doppler for a carotid diaphragm
    explanation: Registry protocol describes the study purpose, not an observed result.
  notes: ClinicalTrials.gov checked 2026-10-04; last posted update 2023-04-27. UNKNOWN is the current registry status; last known recruitment was RECRUITING.
references:
- reference: DOI:10.1038/s41598-024-60666-7
  title: Subjects with carotid webs demonstrate pro-thrombotic hemodynamics compared to subjects with carotid atherosclerosis
- reference: DOI:10.1186/s13244-024-01650-7
  title: 'The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics'
- reference: PMID:26228877
  title: Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
- reference: PMID:33970205
  title: Assessment of Recurrent Stroke Risk in Patients With a Carotid Web.
- reference: PMID:34102760
  title: 'Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.'
- reference: PMID:37724713
  title: 'Clinical, imaging, and management features of symptomatic carotid web: Insight from CAROWEB registry.'
- reference: PMID:39215397
  title: In-hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy.
- reference: PMID:40494576
  title: 'Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.'
- reference: PMID:40503762
  title: 'Carotid Revascularization Versus Medical Management for Ischemic Stroke with Ipsilateral Carotid Web: A Systematic Review and Meta-Analysis.'
- reference: PMID:40776764
  title: 'Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.'
- reference: PMID:40873957
  title: Histopathologic evidence of intimal hyperplasia in carotid artery webs associated with stroke.
- reference: PMID:41885481
  title: 'Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.'
- reference: PMID:42710700
  title: Carotid revascularization is associated with reduced recurrence in symptomatic carotid web.
- reference: clinicaltrials:NCT04431609
  title: French Cohort of Carotid Web Associated With Cerebral Infarctions
- reference: clinicaltrials:NCT04442074
  title: Characteristics in Doppler Ultrasound of the Carotid Diaphragm Responsible for an Ischemic Stroke
- reference: clinicaltrials:NCT05475080
  title: Carotid Web and Stroke Registry. Clinical and Genetic Study. "Registro de Pacientes Con Carotid Web e Ictus. Estudio clínico y genético"
- reference: clinicaltrials:NCT06058507
  title: '"The Incidence of Carotid Web and Its Radiological Classification, Determination of Its Relationship With Ischemic Stroke by Evaluating the Clinical Data and Vascular Risk Factors of Carotid Web Cases"'
- reference: clinicaltrials:NCT06336083
  title: 'Family Screening for Internal Carotid Diaphragm Dysplasia (Carotid WEB): a Doppler Ultrasound Study'
- reference: clinicaltrials:NCT07495241
  title: 'Prevalence of Carotid Web in Youth Assessed by Duplex Sonography: a Cross-Sectional Study'
- reference: url:https://pmc.ncbi.nlm.nih.gov/articles/PMC6927439/
  title: Optical coherence tomography as an adjunct during carotid artery stenting for carotid web - PMC
📚

References & Deep Research

References

20
DOI:10.1038/s41598-024-60666-7
Subjects with carotid webs demonstrate pro-thrombotic hemodynamics compared to subjects with carotid atherosclerosis
No top-level findings curated for this source.
DOI:10.1186/s13244-024-01650-7
The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics
No top-level findings curated for this source.
PMID:26228877
Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography.
No top-level findings curated for this source.
PMID:33970205
Assessment of Recurrent Stroke Risk in Patients With a Carotid Web.
No top-level findings curated for this source.
PMID:34102760
Stroke Recurrence in First-Ever Symptomatic Carotid Web: A Cohort Study.
No top-level findings curated for this source.
PMID:37724713
Clinical, imaging, and management features of symptomatic carotid web: Insight from CAROWEB registry.
No top-level findings curated for this source.
PMID:39215397
In-hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy.
No top-level findings curated for this source.
PMID:40494576
Carotid Web: An Update Focusing on Its Relationship With Fibromuscular Dysplasia and Therapeutic Strategy.
No top-level findings curated for this source.
PMID:40503762
Carotid Revascularization Versus Medical Management for Ischemic Stroke with Ipsilateral Carotid Web: A Systematic Review and Meta-Analysis.
No top-level findings curated for this source.
PMID:40776764
Outcomes after carotid revascularization for symptomatic carotid artery web: A multi-institutional cohort study.
No top-level findings curated for this source.
PMID:40873957
Histopathologic evidence of intimal hyperplasia in carotid artery webs associated with stroke.
No top-level findings curated for this source.
PMID:41885481
Pathologically Confirmed Symptomatic Carotid Webs: Histopathological Features and Long-Term Surgical Outcomes.
No top-level findings curated for this source.
PMID:42710700
Carotid revascularization is associated with reduced recurrence in symptomatic carotid web.
No top-level findings curated for this source.
clinicaltrials:NCT04431609
French Cohort of Carotid Web Associated With Cerebral Infarctions
No top-level findings curated for this source.
clinicaltrials:NCT04442074
Characteristics in Doppler Ultrasound of the Carotid Diaphragm Responsible for an Ischemic Stroke
No top-level findings curated for this source.
clinicaltrials:NCT05475080
Carotid Web and Stroke Registry. Clinical and Genetic Study. "Registro de Pacientes Con Carotid Web e Ictus. Estudio clínico y genético"
No top-level findings curated for this source.
clinicaltrials:NCT06058507
"The Incidence of Carotid Web and Its Radiological Classification, Determination of Its Relationship With Ischemic Stroke by Evaluating the Clinical Data and Vascular Risk Factors of Carotid Web Cases"
No top-level findings curated for this source.
clinicaltrials:NCT06336083
Family Screening for Internal Carotid Diaphragm Dysplasia (Carotid WEB): a Doppler Ultrasound Study
No top-level findings curated for this source.
clinicaltrials:NCT07495241
Prevalence of Carotid Web in Youth Assessed by Duplex Sonography: a Cross-Sectional Study
No top-level findings curated for this source.
url:https://pmc.ncbi.nlm.nih.gov/articles/PMC6927439/
Optical coherence tomography as an adjunct during carotid artery stenting for carotid web - PMC
No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Review carotid web mechanisms, pathology, recurrence and treatment evidence · 2026-10-04T18:09:23Z · View source

Reviewed the existing Carotid_Web entry and its Falcon deep-research report against cached literature, with live PubMed/Europe PMC and ClinicalTrials.gov checks through 2026-10-04. The disorder has only prior EDIT history and is a structural vascular arteriopathy within the requested noninfectious/non-environmental scope. Fresh open-PR file and title-issue checks found no competing curation. GeneReviews baseline check returned NO_CHAPTER. Read the scientific narrative, methods and limitations of the cached full-text CFD study (DOI:10.1038/s41598-024-60666-7), Choi CTA/pathology series (PMID:26228877), early recurrence cohort (PMID:39215397), long-term Afro-Caribbean cohort (PMID:34102760), multicenter revascularization cohort (PMID:40776764), and the 2025 review (PMID:40494576). Read the pathological findings and discussion of PMID:40873957 and targeted ultrasound-study sections (DOI:10.1186/s13244-024-01650-7). Retrieved the public full text for PMID:33970205 as the PMC8111564 URL cache and read its methods, results and limitations; the canonical PMID cache only contained the abstract. Added current 2026 pathological and TCAR series from their retrievable abstracts (PMID:41885481 and PMID:42710700). Attempts to retrieve the latter publisher full text/PDF returned 403. Protocol summaries and raw registry API caches preserve the trial-design and status evidence. Separated the intimal shelf, disturbed flow/stasis, local mural thrombosis, and downstream embolization into atomic nodes. Removed the unsupported platelet-activation assertion from the CFD node and the requirement for stroke or thrombus to diagnose the structural lesion. Histology now distinguishes the non-atheromatous web from possible coexisting atheroma. Retained the main ischemic phenotypes and added supported focal deficits and rare retinal arterial occlusion. Recurrence claims distinguish early thrombectomy-cohort events, the stroke-only MR CLEAN outcome, and the stroke/TIA composite in the Afro-Caribbean cohort. Cohort selection, small event counts, competing atrial fibrillation and nonrandom treatment allocation constrain the interpretation. Separated antithrombotic therapy, endarterectomy, stenting, TCAR, acute thrombectomy and intravenous thrombolysis. Observational low recurrence does not establish zero risk, procedure equivalence or randomized efficacy. The multicenter cohort abstract calls its recurrent event asymptomatic whereas the body calls it symptomatic; the description reports one recurrent stroke without assuming severity. Incidental webs are explicitly separated from symptomatic secondary prevention. Diagnostic coverage includes multiplanar CTA, dynamic contrast stasis, sonography, silent infarcts and dissection/plaque/thrombus differential; concordant imaging is identified as a review proposal. Family/genetic screening and youth prevalence are study aims, not results. Current UNKNOWN statuses replace outdated recruitment assumptions for CAROWEB, the Spanish registry and the Doppler study. OAK verified MONDO, HP, CL, UBERON, GO, CHEBI and NCIT bindings, including central retinal artery occlusion and stroke thrombectomy. The latest bioprinting perspective PMID:42826182 was inspected as a proposal, not treated as a new experimental validation or a source of established hormonal causation. No causal genes, molecular pathways or omics dataset accessions were invented from speculative leads; the CFD dataset is available on request. The broad ANTIQUE atherosclerosis registry was not presented as a web-specific therapeutic trial. Schema, ontology terms and reference validation passed with 65/65 snippets verified, 84 titles checked and none skipped. Causal-target, snippet-boundary, coarse-phenotype, gene-grounding and node-class checks passed. Final repository gates and pre-commit are recorded in the PR validation report.

Falcon ▸
Carotid web — Comprehensive Disease Characteristics Report
Edison Scientific Literature 30 citations 2026-05-05T17:05:45.014046

Carotid web — Comprehensive Disease Characteristics Report

Target disease

  • Disease name: Carotid web (carotid artery web)
  • Category: Complex (vascular anomaly / non-atherosclerotic carotid arteriopathy associated with ischemic stroke)
  • MONDO ID: Not identified from the retrieved sources in this run (see “Key identifiers”).

Executive summary (current understanding; 2023–2024 emphasized)

Carotid web (CaW) is a non-atherosclerotic, shelf-like intimal projection arising classically from the posterior wall of the carotid bulb/proximal internal carotid artery (ICA) and is widely considered an intimal variant of fibromuscular dysplasia (FMD). Contemporary reviews and cohort studies support a mechanistic model in which CaW geometry creates flow separation and stasis in a “web pouch,” promoting local thrombosis and artery-to-artery embolism, leading to embolic cortical infarctions and large-vessel occlusion (LVO) strokes. Recurrence risk on medical therapy appears substantial in symptomatic webs (commonly summarized as ~10% annualized and ~20% over 2 years), whereas small observational series report low recurrence after carotid endarterectomy (CEA) or carotid artery stenting (CAS), though randomized trial data are lacking. (chen2024carotidwebsa pages 1-2, sayed2024subjectswithcarotid pages 1-2, zedde2025carotidweban pages 9-10)

1. Disease information

1.1 What is the disease? (concise overview)

A carotid web is an intraluminal, shelf-like intimal flap in the carotid bulb/proximal ICA. A widely used CTA definition is: “a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation… seen as a septum on axial CTA.” (choi2015carotidwebsand pages 1-3)

Recent narrative reviews similarly define CaW as a “fibrous, shelf-like intimal flap originating from the posterior wall of the internal carotid bulb projecting into the arterial lumen” and emphasize its association with cryptogenic/embolic stroke. (chen2024carotidwebsa pages 1-2)

1.2 Common synonyms / alternative names

  • Carotid artery web (CaW) (chen2024carotidwebsa pages 1-2)
  • Carotid web (CaW/CW) (choi2015carotidwebsand pages 1-3)
  • Carotid diaphragm (term used in ClinicalTrials.gov study title: “carotid diaphragm responsible for ischemic stroke”) (NCT04442074 chunk 2)
  • “Shelf-like intraluminal filling defect” (imaging descriptor) (choi2015carotidwebsand pages 1-3, ahmad2025carotidwebsa pages 1-3)

1.3 Key identifiers (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)

  • MONDO / MeSH / ICD coding: Not confirmed from the retrieved sources in this run. Carotid web is commonly discussed as an imaging-defined lesion and may be coded under broader carotid/artery anomaly or stenosis/disorder categories in clinical systems; however, a specific code could not be evidenced here.

1.4 Evidence source type

The retrieved information is primarily from aggregated disease-level resources (narrative reviews and systematic reviews) and observational human clinical cohorts/series, plus ClinicalTrials.gov registries. (chen2024carotidwebsa pages 1-2, ahmad2025carotidwebsa pages 1-3, NCT04431609 chunk 1)

2. Etiology

2.1 Disease causal factors (current hypotheses)

  • Non-atherosclerotic arteriopathy / intimal FMD phenotype: CaW is repeatedly described as an atypical FMD subtype with pathologic support for intimal fibroplasia/hyperplasia. (chen2024carotidwebsa pages 1-2, zedde2025carotidweban pages 1-2)
  • Potential congenital/developmental contribution: Reviews note debated pathogenesis with proposed developmental origins. (chen2024carotidwebsa pages 1-1)
  • Genetic and/or hormonal contributions (hypothesized, not established): A 2024 review notes “genetic predisposition or hormonal factors” may contribute, but evidence remains limited. (chen2024carotidwebsa pages 1-2)

2.2 Risk factors

Evidence is largely observational and heterogeneous. - Age: Often recognized in “young” patients with otherwise cryptogenic/LVO stroke, though CaW can occur across adult ages. (chen2024carotidwebsa pages 1-2, khan2024in‐hospitalrecurrentstroke pages 1-2) - Sex: Female predominance is repeatedly reported in reviews/cohorts. (chen2024carotidwebsa pages 1-1, ahmad2025carotidwebsa pages 3-4) - Ancestry/ethnicity: Associations with African descent/African American or “black population” are reported. (chen2024carotidwebsa pages 1-2, NCT04431609 chunk 1) - Traditional vascular risk factors: Reviews commonly emphasize CaW-associated strokes in patients lacking conventional risk factors, but CaW can coexist with plaque (a distinct subgroup evaluated in multimodal ultrasound cohorts). (khan2024in‐hospitalrecurrentstroke pages 1-2, hou2024thedifferencesbetween pages 1-3)

2.3 Protective factors

No protective genetic variants or protective environmental factors were identified in the retrieved sources.

2.4 Gene–environment interactions

No CaW-specific gene–environment interaction evidence was identified in the retrieved sources.

3. Phenotypes

3.1 Core clinical phenotypes (human)

Carotid web itself is often asymptomatic until thromboembolism occurs; the clinically salient phenotype is ischemic stroke (often embolic/LVO) or TIA in the ipsilateral carotid territory.

Ischemic stroke (embolic, often LVO) - CaW is linked to embolic strokes and LVO; one review summarizes CaW as contributing to “2.5% of all large vessel occlusion strokes.” (chen2024carotidwebsa pages 1-2) - A thrombectomy cohort study (July 2015–March 2023) found ipsilateral CaW in 27/1463 (1.8%) thrombectomy patients; CaW patients were younger (median 60 vs 74 years) and often had no competing mechanism. (khan2024in‐hospitalrecurrentstroke pages 1-2)

Recurrent ischemic stroke - A classic CTA-era series reported recurrent stroke in 5/7 (71.4%) with recurrence occurring 1–97 months. (choi2015carotidwebsand pages 1-3) - Contemporary summaries cite recurrent events on medical therapy (see Prognosis/Treatment). (chen2024carotidwebsa pages 1-1)

Transient ischemic attack (TIA) - The CAROWEB registry includes patients with “cerebral infarction or transient ischemic attack” downstream of a CaW lesion. (NCT04431609 chunk 1)

3.2 Phenotype characteristics (onset, severity, progression)

  • Onset pattern: Acute neurologic deficits due to ischemic stroke/TIA. (NCT04431609 chunk 1)
  • Severity: Can be severe; CAROWEB describes association with “severe cerebral infarction in the carotid territory.” (NCT04431609 chunk 1)
  • Course: High recurrence risk in symptomatic cases, including in-hospital recurrence after thrombectomy. (khan2024in‐hospitalrecurrentstroke pages 1-2)

3.3 Suggested HPO terms (examples for a knowledge base)

(Exact mapping may vary by curator policy; these are appropriate candidates.) - Ischemic stroke — HP:0002140 - Transient ischemic attack — HP:0002327 - Cerebral infarction — HP:0002140 (often used for stroke) / consider ontology-specific infarction term if used locally - Hemiparesis — HP:0001269 (frequently reported in case presentations) (ahmad2025carotidwebsa pages 12-13) - Aphasia — HP:0002381 (reported in case presentations) (ahmad2025carotidwebsa pages 12-13) - Facial weakness — HP:0030319 (reported in case presentations) (ahmad2025carotidwebsa pages 12-13)

3.4 Quality-of-life impact

QoL instruments (EQ-5D/SF-36/PROMIS) were not reported in the retrieved evidence; functional outcomes in registries are typically captured as modified Rankin Scale (mRS) at 3–6 months (CAROWEB). (NCT04431609 chunk 1)

4. Genetic / molecular information

4.1 Causal genes / pathogenic variants

No CaW-specific causal genes or pathogenic variants were identified from the retrieved primary/clinical literature in this run.

4.2 Evidence for genetic contribution (investigational)

  • Registry plans for polymorphism studies: A prospective CaW registry explicitly includes “detection of genetic polymorphisms associated with CW” as a secondary aim, indicating ongoing investigation rather than established genetics. (NCT05475080 chunk 1)
  • Familial screening study: Family-WEB (NCT06336083) screens first-degree relatives, motivated by epidemiologic signals and possible genetic contribution, while noting no established familial forms to date. (NCT06336083 chunk 1)

4.3 Epigenetics / molecular profiling / multi-omics

No CaW-specific epigenomic/transcriptomic/proteomic/metabolomic signatures were identified in the retrieved sources.

5. Environmental information

No CaW-specific environmental toxins, lifestyle exposures, or infectious triggers were identified in the retrieved sources. CaW is generally framed as a structural arteriopathy rather than an exposure-driven condition. (chen2024carotidwebsa pages 1-2, sayed2024subjectswithcarotid pages 1-2)

6. Mechanism / pathophysiology

6.1 Causal chain (current mechanistic model)

  1. Anatomical lesion: A fibrous, shelf-like intimal flap/projection at the carotid bulb/proximal ICA (often posterior wall). (chen2024carotidwebsa pages 1-2, zedde2025carotidweban pages 9-10)
  2. Hemodynamic disturbance: The web creates disturbed flow with recirculation and stasis in the web pouch. (sayed2024subjectswithcarotid pages 1-2, chen2024carotidwebsa pages 1-2)
  3. Thrombogenesis: Stasis and abnormal shear promote thrombus formation; pathology-based reviews describe “small thrombi embedded in the web pouch.” (zedde2025carotidweban pages 1-2)
  4. Embolization: Thrombus fragments embolize intracranially, producing embolic ischemic stroke, including LVO events. (chen2024carotidwebsa pages 1-2, khan2024in‐hospitalrecurrentstroke pages 1-2)

6.2 Hemodynamics evidence (2024)

A patient-specific computational fluid dynamics (CFD) study comparing CaW vs mild atherosclerosis vs normal bifurcations reported that CaW patients had significantly larger regions of low shear rate, high oscillatory shear index (OSI), low velocity, and flow stasis, consistent with a pro-thrombotic environment. (sayed2024subjectswithcarotid pages 1-2)

6.3 Histopathology evidence (reviewed)

CaW is reviewed as an intimal-FMD-like lesion with intimal hyperplasia/fibroplasia; reviews summarize direct observation of thrombus adherent to or embedded within the lesion. (chen2024carotidwebsa pages 1-2, zedde2025carotidweban pages 3-5)

6.4 Suggested ontology terms

GO biological process (examples): - Blood coagulation — GO:0007596 - Platelet activation — GO:0030168 - Regulation of blood flow — GO:1903522 - Thrombus formation — (often modeled via coagulation/platelet activation terms)

Cell Ontology (CL) candidates (based on thrombosis & intimal remodeling): - Vascular smooth muscle cell — CL:0000192 (implicated by intimal hyperplasia concepts) (chen2024carotidwebsa pages 1-2) - Endothelial cell — CL:0000115 - Platelet — CL:0000233

UBERON anatomy: - Internal carotid artery — UBERON:0001496 - Common carotid artery — UBERON:0001644 - Carotid artery bifurcation / carotid bulb (anatomic region; may require local mapping)

7. Anatomical structures affected

7.1 Organ/system level

  • Primary site: Extracranial carotid bifurcation / proximal ICA (posterior wall predilection emphasized in imaging/pathology reviews). (zedde2025carotidweban pages 9-10)
  • Secondary effect: Brain (ischemic infarction / LVO stroke) downstream of ipsilateral lesion. (khan2024in‐hospitalrecurrentstroke pages 1-2, NCT04431609 chunk 1)

7.2 Tissue/cell level

  • Tissue: Arterial intima (intimal hyperplasia/fibroplasia) (chen2024carotidwebsa pages 1-2)

7.3 Subcellular

No CaW-specific subcellular compartment abnormalities were identified.

8. Temporal development

  • Onset: Often detected after acute ischemic stroke/TIA presentation; can be incidentally found on imaging. (NCT04431609 chunk 1, khan2024in‐hospitalrecurrentstroke pages 1-2)
  • Progression/course: The main clinically relevant temporal feature is risk of recurrence without definitive treatment; in-hospital recurrence after thrombectomy has been quantified (RR estimates). (khan2024in‐hospitalrecurrentstroke pages 1-2)

9. Inheritance and population

9.1 Epidemiology (key statistics)

  • General/hospital prevalence: A hospital-based retrospective series estimated period prevalence 1.2% (7/576; 95% CI 0.4–2.5%). (choi2015carotidwebsand pages 1-3)
  • Prevalence in cryptogenic stroke: Reviews summarize wide ranges; one 2024 imaging cohort review cites 2.5–37% prevalence in cryptogenic stroke literature. (hou2024thedifferencesbetween pages 1-3)
  • Young cryptogenic stroke enrichment: A 2024 review summarizes ~13% frequency among patients with stroke of otherwise unknown etiology and “young” patients with otherwise cryptogenic stroke. (chen2024carotidwebsa pages 1-1)

9.2 Demographics

  • Sex: Female predominance is reported in pooled evidence (systematic review and narrative reviews). (ahmad2025carotidwebsa pages 3-4, chen2024carotidwebsa pages 1-1)
  • Ancestry: Higher prevalence in African descent/black populations is reported in reviews and registries. (chen2024carotidwebsa pages 1-2, NCT04431609 chunk 1)
  • Laterality/bilaterality: A systematic review reports bilateral CaW in 55 patients in pooled data. (ahmad2025carotidwebsa pages 3-4)

9.3 Inheritance

No established Mendelian inheritance pattern is supported in the retrieved sources. Familial screening and polymorphism studies are ongoing/in planning. (NCT06336083 chunk 1, NCT05475080 chunk 1)

10. Diagnostics

10.1 Imaging modalities and diagnostic features

CTA (computed tomography angiography) - Key definition (CTA): “thin intraluminal filling defect… posterior wall… seen as a septum on axial CTA.” (choi2015carotidwebsand pages 1-3) - Oblique/sagittal reconstructions are emphasized in reviews for best visualization. (chen2024carotidwebsa pages 1-2)

DSA (digital subtraction angiography) - Used for diagnostic uncertainty and for intervention planning; reviews describe a linear filling defect with delayed/late contrast retention. (zedde2025carotidweban pages 9-10)

Ultrasound (DUS), CEUS, and microvascular flow imaging (SMI) - A 2024 cohort study used CEUS and SMI to differentiate CaW vs CaW with plaque and to identify typical features (including a thin triangular endoluminal defect on SMI). (hou2024thedifferencesbetween pages 1-3, hou2024thedifferencesbetween media c303a27b)

MRI / Vessel wall MRI (VW-MRI) - A 2025 review summarizes proposed VW-MRI signs (projection, “double lumen sign,” and contrast stasis) and reports improved detection compared with luminal imaging; reported detection advantages include intimal flap detection 42% vs 16% and threefold higher detection vs MRA in one cohort. (zedde2025carotidweban pages 9-10)

10.2 Differential diagnosis

Key differentials explicitly listed in a recent review include: - Arterial dissection - Non-calcified atherosclerotic plaque - Intraluminal thrombus (zedde2025carotidweban pages 9-10)

10.3 Diagnostic performance (available quantitative metrics)

A 2025 review reports high inter-modality agreement between CTA and DSA (e.g., CTA vs DSA κ≈0.92; CTA κ≈0.88 in summarized studies), with lower performance for ultrasound in some comparisons. (zedde2025carotidweban pages 9-10)

10.4 Visual diagnostic exemplars

The following retrieved figure set shows multimodal ultrasound appearances of CaW and CaW with plaque (including SMI depiction of a thin triangular endoluminal defect), supporting real-world implementation of ultrasound-based recognition. (hou2024thedifferencesbetween media c303a27b, hou2024thedifferencesbetween media e72308b7, hou2024thedifferencesbetween media 6a447500)

11. Outcome / prognosis

11.1 Recurrence risk

  • A 2024 review summarizes symptomatic CaW recurrence rates up to ~20% over 2 years and reports an annualized stroke risk on medical therapy ~10% in summarized observational evidence. (chen2024carotidwebsa pages 1-1, chen2024carotidwebsa pages 1-2)
  • A 2024 thrombectomy cohort reported markedly increased in-hospital recurrence risk when an ipsilateral CaW was present (adjusted RR 4.38 for recurrent ischemic stroke; adjusted RR 4.49 for recurrent ipsilateral LVO). (khan2024in‐hospitalrecurrentstroke pages 1-2)

11.2 Functional outcomes

CAROWEB tracks modified Rankin Scale (mRS) at 3–6 months, but the trial record excerpt does not provide quantitative outcome distributions. (NCT04431609 chunk 1)

12. Treatment

12.1 Current practice (observational evidence; no RCTs)

A contemporary review states there are no randomized controlled trials for CaW therapy, and describes treatment options as medical therapy (single/dual antiplatelets; sometimes anticoagulation) versus intervention (CEA or CAS). (zedde2025carotidweban pages 1-2)

12.2 Medical therapy

Observational literature summarized in a 2024 review indicates a ~10% annualized risk on medical therapy in symptomatic webs. (chen2024carotidwebsa pages 1-2)

12.3 Carotid endarterectomy (CEA) and carotid artery stenting (CAS)

  • A 2024 review table summarizes 0% recurrent stroke risk after carotid stenting and 0% after endarterectomy in compiled observational series (recognizing limitations of small samples and selection). (chen2024carotidwebsa pages 1-2)
  • A 2025 review summarizing observational pooled data reports no recurrent strokes in interventionally treated patients versus 26.8% recurrent cerebral ischemia in medically treated patients, while cautioning heterogeneity and potential bias. (zedde2025carotidweban pages 9-10)

12.4 MAXO term suggestions (examples)

  • Antiplatelet therapy — MAXO:0000767
  • Anticoagulant therapy — MAXO:0000740
  • Carotid endarterectomy — (MAXO term for endarterectomy / carotid endarterectomy; map per MAXO catalog)
  • Carotid artery stenting — (MAXO term for endovascular stent placement)
  • Mechanical thrombectomy — (MAXO term for thrombectomy)

12.5 Real-world implementations / care pathways

  • Stroke centers: CaW is increasingly evaluated in young/cryptogenic/LVO stroke workups, and can influence decisions about secondary prevention or revascularization. (chen2024carotidwebsa pages 1-2, khan2024in‐hospitalrecurrentstroke pages 1-2)
  • Imaging practice: Use of CTA with multiplanar reconstructions, plus confirmatory modality concordance (e.g., CTA + ultrasound/VW-MRI) is emphasized. (zedde2025carotidweban pages 9-10)

12.6 Ongoing trials/registries (ClinicalTrials.gov)

  • CAROWEB registry (France): NCT04431609, prospective multicenter cohort/registry (start 2019-06-19; planned completion 2026-06-30) capturing imaging, management, mRS, and recurrence. (NCT04431609 chunk 1)
  • Carotid Web and Stroke Registry: NCT05475080 (start 2022-07-15; primary completion estimate 2024-07-15), compares recurrence by preventive treatment and includes genetic polymorphism investigation. (NCT05475080 chunk 1)
  • Familial screening: NCT06336083 (Family-WEB; start 2024-09-11), ultrasound screening of first-degree relatives. (NCT06336083 chunk 1)
  • Youth prevalence (population DUS): NCT07495241 (start 2026-01-04), estimates prevalence in ages 15–25; includes CTA validation subset. (NCT07495241 chunk 1)
  • Radiologic classification/incidence (completed): NCT06058507 (retrospective cohort; completion 2023-08-20). (NCT06058507 chunk 1)

13. Prevention

13.1 Primary prevention

No established primary prevention strategies specific to CaW were identified; CaW is not currently a target of population screening in standard guidelines based on the retrieved evidence.

13.2 Secondary/tertiary prevention

Secondary prevention focuses on preventing recurrent embolic events in patients with diagnosed CaW, using antithrombotic therapy and/or definitive revascularization in selected cases, acknowledging the lack of RCTs. (zedde2025carotidweban pages 1-2)

14. Other species / natural disease

No evidence of CaW as a naturally occurring disease model in non-human species was identified in the retrieved sources.

15. Model organisms

No established model organisms for CaW were identified in the retrieved sources.

Key quantitative findings table

Domain Key finding Population/study design (n, setting) Year Source (journal/registry) Identifier (DOI or NCT) URL
Definition Carotid web defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the bifurcation, seen as a septum on axial CTA (choi2015carotidwebsand pages 1-3) Prospective + retrospective hospital-based imaging series; retrospective denominator 576 CTA/MRI patients 2015 American Journal of Neuroradiology DOI: 10.3174/ajnr.a4431 https://doi.org/10.3174/ajnr.a4431
Definition Carotid web described as a fibrous, shelf-like intimal flap from the posterior wall of the ICA bulb; review notes overall incidence largely unknown (chen2024carotidwebsa pages 1-2) Narrative review of observational literature 2024 Journal of NeuroInterventional Surgery DOI: 10.1136/jnis-2023-021243 https://doi.org/10.1136/jnis-2023-021243
Definition Carotid web defined as intimal fibromuscular dysplasia with a shelf-like projection of intimal fibrous tissue into the carotid bulb (hou2024thedifferencesbetween pages 1-3) Retrospective imaging cohort n=299 diagnosed by CTA or HRMRI and evaluated by multimodal ultrasound 2024 Insights into Imaging DOI: 10.1186/s13244-024-01650-7 https://doi.org/10.1186/s13244-024-01650-7
Definition / pathology Review states carotid web was historically described as an atypical FMD subtype with pathological evidence supporting intimal FMD (zedde2025carotidweban pages 9-10) Narrative review of pathology/imaging/therapy literature 2025 Journal of Stroke DOI: 10.5853/jos.2025.00626 https://doi.org/10.5853/jos.2025.00626
Epidemiology Hospital-based period prevalence 7/576 = 1.2% (95% CI 0.4%–2.5%) (choi2015carotidwebsand pages 1-3) Retrospective hospital series with baseline head/neck CTA followed by brain MRI 2015 American Journal of Neuroradiology DOI: 10.3174/ajnr.a4431 https://doi.org/10.3174/ajnr.a4431
Epidemiology Prospective series mean age 50 years (range 41–55); 5/7 women (71.4%) (choi2015carotidwebsand pages 1-3) Prospective single-center case series n=7 2015 American Journal of Neuroradiology DOI: 10.3174/ajnr.a4431 https://doi.org/10.3174/ajnr.a4431
Epidemiology Review table reports prevalence estimates of <1% in total population and 13% among patients with stroke of otherwise unknown etiology (chen2024carotidwebsa pages 1-2) Review of published observational studies 2024 Journal of NeuroInterventional Surgery DOI: 10.1136/jnis-2023-021243 https://doi.org/10.1136/jnis-2023-021243
Epidemiology Cryptogenic stroke association reported range 2.5%–37%; conservative-therapy recurrence range 11.4%–27.3% (hou2024thedifferencesbetween pages 1-3) Review statements within retrospective multimodal ultrasound cohort paper 2024 Insights into Imaging DOI: 10.1186/s13244-024-01650-7 https://doi.org/10.1186/s13244-024-01650-7
Epidemiology Systematic review pooled 771 patients from 123 articles (registry/cohort 559; case series/reports 212); higher prevalence reported in younger patients, females, and Afro-Caribbean individuals (ahmad2025carotidwebsa pages 1-3) PRISMA systematic review 2025 Journal of Vascular Societies Great Britain & Ireland DOI: 10.54522/jvsgbi.2025.164 https://doi.org/10.54522/jvsgbi.2025.164
Recurrence Recurrent stroke occurred in 5/7 (71.4%); time to recurrence 1–97 months (choi2015carotidwebsand pages 1-3) Prospective case series n=7 2015 American Journal of Neuroradiology DOI: 10.3174/ajnr.a4431 https://doi.org/10.3174/ajnr.a4431
Recurrence / treatment Review reports symptomatic carotid webs have recurrence rates as high as 20% over 2 years (chen2024carotidwebsa pages 1-2) Narrative review of observational data 2024 Journal of NeuroInterventional Surgery DOI: 10.1136/jnis-2023-021243 https://doi.org/10.1136/jnis-2023-021243
Treatment Review table reports annualized stroke risk on medical therapy ~10%, versus 0% after carotid stenting and 0% after endarterectomy in summarized observational literature (chen2024carotidwebsa pages 1-2) Review of published observational studies 2024 Journal of NeuroInterventional Surgery DOI: 10.1136/jnis-2023-021243 https://doi.org/10.1136/jnis-2023-021243
Treatment Review cites pooled comparison: 0 recurrent strokes in 138 interventionally treated patients vs 26.8% recurrent cerebral ischemia in 151 medically treated patients; authors caution data are heterogeneous and potentially biased (zedde2025carotidweban pages 9-10) Narrative review pooling observational cohorts 2025 Journal of Stroke DOI: 10.5853/jos.2025.00626 https://doi.org/10.5853/jos.2025.00626
Pathophysiology CFD study found CaW patients had significantly larger regions of low shear rate, high oscillatory shear index, low velocity, and flow stasis than mild atherosclerosis or normal bifurcations (sayed2024subjectswithcarotid pages 1-2) Patient-specific CFD using CTA geometries + 2D phase-contrast MRI inflow; CaW n=13, mild atherosclerosis n=7, healthy n=6 2024 Scientific Reports DOI: 10.1038/s41598-024-60666-7 https://doi.org/10.1038/s41598-024-60666-7
Pathophysiology Review summarizes thrombogenic mechanism as disturbed flow with stasis in the web pouch causing artery-to-artery embolism; pathology has identified small thrombi embedded in the web pouch (zedde2025carotidweban pages 9-10) Narrative review of pathology and hemodynamic literature 2025 Journal of Stroke DOI: 10.5853/jos.2025.00626 https://doi.org/10.5853/jos.2025.00626
Diagnostics CTA is emphasized as primary acute diagnostic tool; diagnosis often requires concordance of 2 non-invasive modalities, with DSA reserved for diagnostic uncertainty/intervention planning (zedde2025carotidweban pages 9-10) Narrative review 2025 Journal of Stroke DOI: 10.5853/jos.2025.00626 https://doi.org/10.5853/jos.2025.00626
Diagnostics VW-MRI diagnostic proposal includes thickness, posterior projection, “value sign,” “double lumen sign,” and contrast stasis; one cohort showed 3-fold higher detection than MRA, and intimal flaps were seen in 42% of dissections vs 16% by luminal techniques (zedde2025carotidweban pages 9-10) Narrative review summarizing imaging studies 2025 Journal of Stroke DOI: 10.5853/jos.2025.00626 https://doi.org/10.5853/jos.2025.00626
Diagnostics Multimodal ultrasound/clinical cohort included 299 patients, mean age 60.85 ± 8.77 years; web length independently predicted luminal stenosis in isolated CW, while luminal stenosis and plaque length predicted symptoms in CW with plaque (hou2024thedifferencesbetween pages 1-3) Retrospective cohort; CTA or HRMRI diagnosis plus CEUS and SMI from 2015–2022 2024 Insights into Imaging DOI: 10.1186/s13244-024-01650-7 https://doi.org/10.1186/s13244-024-01650-7
Trial / registry Prospective multicenter registry comparing ischemic recurrences by preventive treatment; target enrollment 100; adults with stroke/TIA and CW diagnosed by angioCT, angioMRI, or arteriography; includes optional genetic polymorphism analysis (NCT05475080 chunk 1) Multicenter prospective observational registry 2022 ClinicalTrials.gov NCT05475080 https://clinicaltrials.gov/study/NCT05475080
Trial / registry CAROWEB French multicenter prospective registry; target enrollment 300; adults with validated carotid web and downstream cerebral infarction/TIA; outcomes include imaging phenotype, management, mRS, bleeding, and recurrence (NCT04431609 chunk 1) National prospective observational cohort/registry 2019 ClinicalTrials.gov NCT04431609 https://clinicaltrials.gov/study/NCT04431609
Trial / familial Family-WEB pilot screens first-degree relatives of index cases; estimated enrollment 90; aims to determine prevalence of carotid web in relatives by Doppler ultrasound, motivated by possible familial/genetic contribution (NCT06336083 chunk 1) Single-center screening study 2024 ClinicalTrials.gov NCT06336083 https://clinicaltrials.gov/study/NCT06336083
Trial / prevalence CaWY cross-sectional survey estimates point prevalence in ages 15–25 by duplex sonography; planned sample 829 (minimum calculated 753); hypothesis prevalence ~2%; includes CTA validation subset (NCT07495241 chunk 1, NCT07495241 chunk 2) Multicenter population-based cross-sectional cohort 2026 ClinicalTrials.gov NCT07495241 https://clinicaltrials.gov/study/NCT07495241
Trial / incidence Completed retrospective cohort, enrollment 31, designed to determine carotid web incidence, radiologic classification, and relationship with ischemic stroke/TIA using CTA and/or DSA (NCT06058507 chunk 1) Retrospective observational cohort 2022 ClinicalTrials.gov NCT06058507 https://clinicaltrials.gov/study/NCT06058507

Table: This table compiles the main quantitative findings, standard definitions, diagnostic features, treatment outcomes, and active registry/trial characteristics for carotid web from the cited evidence. It is useful as a quick reference for building a structured disease knowledge base entry.

Evidence gaps and expert interpretation

  1. No RCT-level evidence for treatment: Multiple authoritative reviews emphasize that management is based on observational cohorts/series and expert practice rather than randomized trials. (zedde2025carotidweban pages 1-2, zedde2025carotidweban pages 9-10)
  2. Highly variable prevalence estimates: Reported CaW prevalence depends strongly on case definition, imaging technique (including reconstruction planes), and selection of cryptogenic/LVO cohorts. (hou2024thedifferencesbetween pages 1-3, chen2024carotidwebsa pages 1-1)
  3. Genetics remains investigational: Ongoing registries and familial screening studies indicate a plausible genetic contribution, but causal genes/variants are not established in the retrieved clinical literature. (NCT05475080 chunk 1, NCT06336083 chunk 1)

URLs and publication dates (selected key sources)

  • Chen et al. J NeuroIntervent Surg (Jan 2024). https://doi.org/10.1136/jnis-2023-021243 (chen2024carotidwebsa pages 1-2)
  • El Sayed et al. Scientific Reports (May 2024). https://doi.org/10.1038/s41598-024-60666-7 (sayed2024subjectswithcarotid pages 1-2)
  • Hou et al. Insights into Imaging (Mar 2024). https://doi.org/10.1186/s13244-024-01650-7 (hou2024thedifferencesbetween pages 1-3)
  • Khan et al. Ann Clin Transl Neurol (Aug 2024). https://doi.org/10.1002/acn3.52161 (khan2024in‐hospitalrecurrentstroke pages 1-2)
  • Choi et al. AJNR (Nov 2015). https://doi.org/10.3174/ajnr.a4431 (choi2015carotidwebsand pages 1-3)
  • CAROWEB registry: https://clinicaltrials.gov/study/NCT04431609 (NCT04431609 chunk 1)
  • Carotid Web and Stroke Registry: https://clinicaltrials.gov/study/NCT05475080 (NCT05475080 chunk 1)
  • Family-WEB: https://clinicaltrials.gov/study/NCT06336083 (NCT06336083 chunk 1)
  • CaWY youth prevalence: https://clinicaltrials.gov/study/NCT07495241 (NCT07495241 chunk 1)

References

  1. (chen2024carotidwebsa pages 1-2): Huanwen Chen, Marco Colasurdo, Matias Costa, Erez Nossek, and Peter Kan. Carotid webs: a review of pathophysiology, diagnostic findings, and treatment options. Journal of NeuroInterventional Surgery, 16:1294-1298, Jan 2024. URL: https://doi.org/10.1136/jnis-2023-021243, doi:10.1136/jnis-2023-021243. This article has 39 citations and is from a domain leading peer-reviewed journal.

  2. (sayed2024subjectswithcarotid pages 1-2): Retta El Sayed, Carissa J. Lucas, Hannah L. Cebull, Fadi B. Nahab, Diogo C. Haussen, Jason W. Allen, and John N. Oshinski. Subjects with carotid webs demonstrate pro-thrombotic hemodynamics compared to subjects with carotid atherosclerosis. Scientific Reports, May 2024. URL: https://doi.org/10.1038/s41598-024-60666-7, doi:10.1038/s41598-024-60666-7. This article has 13 citations and is from a peer-reviewed journal.

  3. (zedde2025carotidweban pages 9-10): Marialuisa Zedde, Maria Simona Stoenoiu, Alexandre Persu, and Rosario Pascarella. Carotid web: an update focusing on its relationship with fibromuscular dysplasia and therapeutic strategy. Journal of Stroke, 27:169-183, May 2025. URL: https://doi.org/10.5853/jos.2025.00626, doi:10.5853/jos.2025.00626. This article has 7 citations and is from a domain leading peer-reviewed journal.

  4. (choi2015carotidwebsand pages 1-3): P.M.C. Choi, D. Singh, A. Trivedi, E. Qazi, D. George, J. Wong, A.M. Demchuk, M. Goyal, M.D. Hill, and B.K. Menon. Carotid webs and recurrent ischemic strokes in the era of ct angiography. American Journal of Neuroradiology, 36:2134-2139, Nov 2015. URL: https://doi.org/10.3174/ajnr.a4431, doi:10.3174/ajnr.a4431. This article has 273 citations and is from a peer-reviewed journal.

  5. (NCT04442074 chunk 2): Characteristics in Doppler Ultrasound of the Carotid Diaphragm Responsible for an Ischemic Stroke. Fondation Hôpital Saint-Joseph. 2020. ClinicalTrials.gov Identifier: NCT04442074

  6. (ahmad2025carotidwebsa pages 1-3): M. Ahmad, M. Tan, M. Abuarqoub, K. Patel, F. Siracusa, J. Shalhoub, and A. Davies. Carotid webs: a review of diagnosis and management strategies in current literature. Journal of Vascular Societies Great Britain & Ireland, 4:99-110, Feb 2025. URL: https://doi.org/10.54522/jvsgbi.2025.164, doi:10.54522/jvsgbi.2025.164. This article has 2 citations.

  7. (NCT04431609 chunk 1): Carotid Web Associated With Cerebral Infarctions. University Hospital, Bordeaux. 2019. ClinicalTrials.gov Identifier: NCT04431609

  8. (zedde2025carotidweban pages 1-2): Marialuisa Zedde, Maria Simona Stoenoiu, Alexandre Persu, and Rosario Pascarella. Carotid web: an update focusing on its relationship with fibromuscular dysplasia and therapeutic strategy. Journal of Stroke, 27:169-183, May 2025. URL: https://doi.org/10.5853/jos.2025.00626, doi:10.5853/jos.2025.00626. This article has 7 citations and is from a domain leading peer-reviewed journal.

  9. (chen2024carotidwebsa pages 1-1): Huanwen Chen, Marco Colasurdo, Matias Costa, Erez Nossek, and Peter Kan. Carotid webs: a review of pathophysiology, diagnostic findings, and treatment options. Journal of NeuroInterventional Surgery, 16:1294-1298, Jan 2024. URL: https://doi.org/10.1136/jnis-2023-021243, doi:10.1136/jnis-2023-021243. This article has 39 citations and is from a domain leading peer-reviewed journal.

  10. (khan2024in‐hospitalrecurrentstroke pages 1-2): Farhan Khan, Narendra Kala, Kelvin Chang, Liqi Shu, Eric D. Goldstein, Radmehr Torabi, Krisztina Moldovan, Mahesh Jayaraman, Nahid Mohammadzadeh, Karen Furie, and Shadi Yaghi. In‐hospital recurrent stroke in ipsilateral carotid web patients undergoing thrombectomy. Annals of Clinical and Translational Neurology, 11:2450-2456, Aug 2024. URL: https://doi.org/10.1002/acn3.52161, doi:10.1002/acn3.52161. This article has 10 citations and is from a peer-reviewed journal.

  11. (ahmad2025carotidwebsa pages 3-4): M. Ahmad, M. Tan, M. Abuarqoub, K. Patel, F. Siracusa, J. Shalhoub, and A. Davies. Carotid webs: a review of diagnosis and management strategies in current literature. Journal of Vascular Societies Great Britain & Ireland, 4:99-110, Feb 2025. URL: https://doi.org/10.54522/jvsgbi.2025.164, doi:10.54522/jvsgbi.2025.164. This article has 2 citations.

  12. (hou2024thedifferencesbetween pages 1-3): Chao Hou, Shuo Li, Lei Zhang, Wei Zhang, and Wen He. The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics. Insights into Imaging, Mar 2024. URL: https://doi.org/10.1186/s13244-024-01650-7, doi:10.1186/s13244-024-01650-7. This article has 7 citations and is from a peer-reviewed journal.

  13. (ahmad2025carotidwebsa pages 12-13): M. Ahmad, M. Tan, M. Abuarqoub, K. Patel, F. Siracusa, J. Shalhoub, and A. Davies. Carotid webs: a review of diagnosis and management strategies in current literature. Journal of Vascular Societies Great Britain & Ireland, 4:99-110, Feb 2025. URL: https://doi.org/10.54522/jvsgbi.2025.164, doi:10.54522/jvsgbi.2025.164. This article has 2 citations.

  14. (NCT05475080 chunk 1): Carotid Web and Stroke Registry.. Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau. 2022. ClinicalTrials.gov Identifier: NCT05475080

  15. (NCT06336083 chunk 1): Familial Form of Carotid Web: a Doppler Ultrasound Study. University Hospital, Toulouse. 2024. ClinicalTrials.gov Identifier: NCT06336083

  16. (zedde2025carotidweban pages 3-5): Marialuisa Zedde, Maria Simona Stoenoiu, Alexandre Persu, and Rosario Pascarella. Carotid web: an update focusing on its relationship with fibromuscular dysplasia and therapeutic strategy. Journal of Stroke, 27:169-183, May 2025. URL: https://doi.org/10.5853/jos.2025.00626, doi:10.5853/jos.2025.00626. This article has 7 citations and is from a domain leading peer-reviewed journal.

  17. (hou2024thedifferencesbetween media c303a27b): Chao Hou, Shuo Li, Lei Zhang, Wei Zhang, and Wen He. The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics. Insights into Imaging, Mar 2024. URL: https://doi.org/10.1186/s13244-024-01650-7, doi:10.1186/s13244-024-01650-7. This article has 7 citations and is from a peer-reviewed journal.

  18. (hou2024thedifferencesbetween media e72308b7): Chao Hou, Shuo Li, Lei Zhang, Wei Zhang, and Wen He. The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics. Insights into Imaging, Mar 2024. URL: https://doi.org/10.1186/s13244-024-01650-7, doi:10.1186/s13244-024-01650-7. This article has 7 citations and is from a peer-reviewed journal.

  19. (hou2024thedifferencesbetween media 6a447500): Chao Hou, Shuo Li, Lei Zhang, Wei Zhang, and Wen He. The differences between carotid web and carotid web with plaque: based on multimodal ultrasonic and clinical characteristics. Insights into Imaging, Mar 2024. URL: https://doi.org/10.1186/s13244-024-01650-7, doi:10.1186/s13244-024-01650-7. This article has 7 citations and is from a peer-reviewed journal.

  20. (NCT07495241 chunk 1): Vendula Krcmarova. Prevalence of Carotid Web in Youth. University of Ostrava. 2026. ClinicalTrials.gov Identifier: NCT07495241

  21. (NCT06058507 chunk 1): Ekin Öykü Baylam Yirmibeş. "Carotid Web Incidence and Radiological Classification, Determination of Its Relationship With Ischemic Stroke". Suleyman Demirel University. 2022. ClinicalTrials.gov Identifier: NCT06058507

  22. (NCT07495241 chunk 2): Vendula Krcmarova. Prevalence of Carotid Web in Youth. University of Ostrava. 2026. ClinicalTrials.gov Identifier: NCT07495241