Baseline Characteristics of Patients with Symptomatic Carotid Webs: A Matched Case Control Study

A case of carotid web with rapid thrombus expansion following mechanical thrombectomy with pathological evaluation by carotid endarterectomy

A 48-year-old man with no history of diagnosis with any abnormality was admitted to our hospital 43 min after onset of stroke. He had a right conjugate deviation and severe left hemiparesis, and his initial National Institutes of Health Stroke Scale (NIHSS) score was 13. Computed tomography (CT) of the head revealed no early ischemic changes, while CT angiography showed occlusion of the M1 proximal segment of the right middle cerebral artery. Intravenous thrombolysis was administered within 27 min of admission, and mechanical thrombectomy was performed. Effective reperfusion was achieved 55 min after puncture. Carotid web (CaW) at the root of the right internal carotid artery was suspected to be the source of the embolus. Carotid ultrasonography (CUS) on the following day revealed an oval-shaped structure of equal intensity rising from the far wall. The structure enlarged over time, despite the administration of an antiplatelet agent. In addition to thrombi, intramural hematoma and neoplastic lesions were considered in the differential diagnosis. Carotid endarterectomy was performed on day 6. Pathologically, a mixed thrombus was identified adhering to the CaW; however, no neoplastic changes were observed. There were no postoperative complications, and the patient was discharged without neurological deficits on day 14. The CaW has anatomical factors morphologically associated with a high risk of thrombus formation. Pathologically, the involvement of hydrodynamic factors was considered more significant than the influence of the CaW surface morphology. CUS is a useful tool for assessing thrombus morphology.

Optical Coherence Tomography in the Evaluation of Suspected Carotid Webs

BACKGROUND

Carotid web (CaW) is a subtype of fibromuscular dysplasia that predominantly involves the intimal layer of the arterial wall and is commonly overlooked as a separate causative entity for recurrent strokes. CaW is defined as a shelf-like lesion at the carotid bulb, although different morphological features have been reported. Optical coherence tomography (OCT) has been described in the literature as a useful microscopic and cross-sectional tomographic imaging tool. This study aimed to evaluate the potential utility of OCT in characterizing the wall structure features of patients with suspected CaW.

METHODS

Retrospective analysis of patients with suspected CaW who underwent digital subtraction angiography (DSA) coupled with OCT of the carotid bulb from 2018 to 2021 in a single comprehensive stroke center.

RESULTS

Sixteen patients were included. The median age was 56 years (IQR 46-61) and 50% were women. OCT corroborated the diagnosis of CaW in 12/16 (75%) cases and ruled it out in 4/16 (25%) patients in whom atherosclerotic disease was demonstrated. Five of the 12 lesions demonstrated a thick fibrotic ridge consistent with CaW but also showed atherosclerotic changes in the vicinity of the carotid bulb (labeled as "CaW+"). In 4/16 (25%) patients, microthrombi adhered to the vessel wall were noted on OCT (inside the CaW pocket or just distal to the web), none of which were observed on CT angiography or DSA.

CONCLUSIONS

OCT may have value as a complementary imaging tool in the investigation of patients with suspected CaW and atypical morphological features. Further studies are warranted.

Carotid web: Pathophysiology, diagnostic, and therapeutic options. A narrative review

A carotid web (CaWeb), otherwise known as a carotid bulb diaphragm, is a spur of intimal fibrous tissue extending into the carotid bulb. It is a rare, underdiagnosed cause of ischemic strokes in young people. The purpose of this narrative review was to provide an update on CaWebs, highlighting recent evolutions in their management. We undertook a comprehensive literature search on main electronic databases - MEDLINE/PubMed, Cochrane Library, Web of Science, and EMBASE - using a dedicated equation to include studies up to February 13, 2024. We also searched for the most recent guidelines about carotid disease or stroke including CaWeb management. A CaWeb is found in up to 10% of young patients, particularly young women, with severe anterior stroke due to an arterial-arterial embolism from the intra-nidus thrombus. Most patients with a CaWeb have less than 50% stenosis on duplex ultrasound, and diagnosis is mostly obtained by computed tomography angiography. When applying traditional stenosis criteria for symptomatic disease (> 50% stenosis), this highly morbid condition is easily overlooked, leading to recurrent strokes. Antithrombotic treatment is associated with a high recurrence rate of stroke after the index event. The first-line treatment of symptomatic CaWebs is increasingly based on endarterectomy or stenting. The lack of recommendations before 2021 and recent discordant guidelines make CaWeb management complex. No guidelines are available to manage patients with asymptomatic CaWebs. Results from ongoing multicenter registries will be useful in guiding management decisions.

Symptomatic carotid webs and patent foramen ovale: RoPE score in competing stroke etiologies

BACKGROUND

Patent foramen ovale (PFO)-associated stroke is diagnosed more frequently in young patients with infrequent vascular risk factors and embolic appearing infarcts. The risk of paradoxical embolism (RoPE) score is used to identify PFO-associated stroke. Patients with symptomatic carotid artery web (CaW) share a very similar risk profile and these lesions are frequently overlooked. In this study, we evaluate the RoPE score profile in patients with suspected symptomatic CaW.

METHODS

Retrospective analysis of prospectively collected data of patients with symptomatic CaW as the presumed cause of stroke presenting to 2 comprehensive stroke centers from 2014 to 2021. CaW was diagnosed using computed tomography angiography (CTA) of the neck & head. Shunt study was done using a transthoracic, transesophageal, and/or transcranial-Doppler with bubbles. RoPE score ≥7 was considered high.

RESULTS

Seventy-five patients had stroke from a symptomatic ipsilateral CaW. Mean age was 49.7±11.2 years and 74.7 % were females. Median RoPE score was 7 [5-8], and 52.0 % had a high RoPE score. PFO was detected in 13.3 % of the patients and 20.5 % within the high RoPE score group. Ten percent of the cases would have been misclassified as PFO-associated strokes based on RoPE score.

CONCLUSION

High RoPE scores were observed in the majority of patients with CaW-attributed stroke, and it should not be used to differentiate CaW- versus PFO-associated stroke. Careful extracranial internal carotid artery evaluation for CaW is warranted in cryptogenic strokes, including in PFO positive patients before defining stroke etiology.

Carotid web catheter angiography hemodynamic parameters

BACKGROUND

Carotid web (CaW)-related contrast stagnation on digital subtraction angiography (DSA) may be a marker supporting the pathophysiological theory of stasis and thrombosis/embolization. We aim to assess the correlation between DSA hemodynamic parameters with CT angiography (CTA) structural measurements and clinical characteristics.

METHODS

Cross-sectional analysis of consecutive patients with CaW who underwent CTA+DSA. DSA-derived hemodynamic parameters were calculated based on a region of interest at the carotid bulb (time-density curves; TDC). The correlation between duration of contrast stagnation with CaW structural features and with clinical characteristics was evaluated with a mixed effects model.

RESULTS

Sixty patients of mean±SD age 52.2±10.3 years were included, of whom 38 (63.3%) were women, 51 (85%) were black, and 59 (98.3%) had symptomatic lesions. The median CaW base was 2.46 mm (range 1.95-3.76), length 2.7 mm (range 2.15-3.96), thickness (length/base) 1.05 (IQR 0.81-1.36), caudal angle 31.93° (IQR 22.35-43.58), mean±SD distal angle 66.91±15.84°, pocket area 1.62 mm² (0.96-1.62), and pocket perimeter 6.03±2.6 mm. The TDC consistently showed an initial fast decay from the peak concentration followed by a plateau with a negative exponential pattern. The median stagnation time from peak density to 80% contrast clearance was 2.91 s (range 1.81-4.94). No significant associations were observed between the stagnation time and CaW CTA structural measurements (length/base/thickness, caudal and cranial angles web surface angles, web pocket area/perimeter) or clinical characteristics.

CONCLUSIONS

A negative exponential pattern in the DSA contrast clearance of the CaW pocket was observed. There were no morphological or clinical features clearly associated with the duration of contrast stagnation on DSA. The hemodynamic disruption caused by CaW and its thrombotic risk may not be appropriately measured by contrast stagnation time.

Comparative analysis between 1-D, 2-D and 3-D carotid web quantification

BACKGROUND

Carotid webs (CaW) are now recognized as a cause of ischemic stroke in young patients. The thromboembolic potential appears related to the CaW's morphology and consequent impact on local flow dynamics. We aim to evaluate the reliability of different measurement methods for the quantification of CaW and their relationship to symptomatic status, presence of large vessel occlusion stroke (LVOS), clot burden and final infarct volume.

METHODS

This was a retrospective analysis of the local comprehensive stroke center CaW database (September 2014-July 2019). CT angiograms (CTAs) were reviewed independently by two raters, blinded to the clinical information and laterality of the stroke/transient ischemic attack. CaW were quantified with 1-D (length), 2-D (area) and 3-D (volume) measurements via Osirix software. Final infarct volume was calculated on MRI. Patients with superimposed CaW thrombus and no repeat imaging were excluded.

RESULTS

Forty-eight CaW (37 symptomatic and 11 contralateral/asymptomatic) in 38 patients were included. Mean age (±SD) was 48.7 (±8.5) years, 78.9% were women and 77.1% were black. Inter-rater agreement was 0.921 (p<0.001) for 1-D, 0.930 (p<0.001) for 2-D, and 0.937 (p<0.001) for 3-D CaW measurements. When comparing symptomatic with asymptomatic CaW, mean web length was 3.2 mm versus 2.5 mm (p<0.02), median area was 5.8 versus 5.0 mm² (p=0.35) and median volume was 15.0 versus 10.6 mm³ (p<0.04), respectively. CaW with a thinner profile (longer intraluminal projection compared with the base) were more likely to be symptomatic (0.67±0.17 vs 0.88±0.37; p=0.01). Average CaW 1-D and final infarct volume had a weak but positive association (Κ=0.230, p<0.05), while no association among web measurements and the presence of LVOS or clot burden was observed.

CONCLUSION

CaW dimension quantification (1-D, 2-D and 3-D) is highly reproducible. Linear and volumetric measurements were more strongly associated with symptoms. The impact of CaW size on the presence of LVOS, clot burden and final infarct volume is unclear.

Multimodality imaging of carotid web: A case report and literature review

Objectives

The carotid web is a compelling potential mechanism of cryptogenic stroke. It is easy for it to escape diagnosis or be misdiagnosed, since it rarely causes hemodynamic stenosis. Currently, there is a lack of consensus on the prevalence, etiology, imaging evaluation, and treatment strategy of carotid artery. We aimed to present the multimodal imaging of carotid web and comprehensively review the characteristics of carotid web.

Methods

A 38 year-old man with carotid web, who presented with acute left hemispheric syndrome, was not identified by computed tomography angiography and high-resolution magnetic resonance imaging in the initial report, but were identified in retrospect and then confirmed by digital subtraction angiography and histopathology. A literature review of carotid web was performed to identify prevalence, nature history, imaging tools, and optimal management of carotid web.

Results

80 reports including 681 patients with carotid web were identified. The prevalence of symptomatic carotid web was 1.2% in patients with transient ischemic attack/stroke, 6.4% in patients with cryptogenic ischemic stroke, 1.1% in patients with large vessel occlusion stroke, and 4.4% in patients who operated on for carotid stenosis. A total of 23.0% patients had bilateral carotid web. In most patients, carotid web was located on the posterior wall (87.3%) of the carotid artery (98.7%). The mean length was 3.3 mm and mean stenosis rate was 20.9%. A total of 31.6% percent patients had thrombus trapped in carotid web and 75.9% patients had large vessel occlusion. Computed tomography angiography and digital subtraction angiography were favorable tools to detect carotid web. There were rare periprocedural complications and no recurrent strokes in carotid revascularization patients.

Conclusions

carotid web is an under-recognized cause of ischemic stroke. It is easy to be missed or misdiagnosed. Carotid revascularization can effectively prevent recurrent stroke for patients with symptomatic carotid web. Clinicians should strength their learning and understanding of carotid web.

Carotid Web Phenotype Is Uncommonly Associated With Classic Fibromuscular Dysplasia: A Retrospective Observational Study

BACKGROUND AND PURPOSE

Carotid web (CaW) is an intimal form of fibromuscular dysplasia (FMD) involving the carotid bulb which has been increasingly recognized as a potential cause of recurrent ischemic strokes. It is overlooked as a separate entity and often dismissed if no coexistent signs of classic FMD changes are observed. We aim to evaluate the frequency of classic FMD in high-yield vascular territories in patients with symptomatic CaW.

METHODS

This was a retrospective analysis of a symptomatic CaW database of 2 comprehensive stroke centers (spanning September 2014-October 2020). The diagnosis of a CaW during a stroke workup was defined as the presence of a shelf-like linear filling defect in the posterior aspect of the carotid bulb on computed tomography angiography in patients with acute ischemic stroke or transient ischemic attack of undetermined cause after a thorough evaluation. Neck computed tomography angiography and renal conventional angiography images were independently evaluated by two readers blinded to the laterality and clinical details to inspect the presence of underlying classic FMD.

RESULTS

Sixty-six patients with CaW were identified. Median age was 51 years (interquartile range, 42-57), and 74% were women. All patients had neck computed tomography angiography (allowing for bilateral vertebral and carotid evaluation), whereas 47 patients had additional digital subtraction angiography (which evaluated 47 carotids ipsilateral to the stroke and 10 contralateral carotids). Internal carotid artery classic FMD changes were noted in only 6 out of 66 (9%) in the ipsilateral carotids. No contralateral carotid or vertebral artery classic FMD changes were observed. Renal artery catheter-based angiography was obtained in 16 patients/32 arteries and only 1 patient/2 renal arteries demonstrated classic FMD changes.

CONCLUSIONS

CaW phenotype is uncommonly associated with classic FMD changes. Coexistent classic FMD does not constitute a useful marker to corroborate or exclude CaW diagnosis.