The carotid web: a developmental anomaly of the brachiocephalic system

Histopathological Examination of a Symptomatic Carotid Web: A Case Report

Carotid webs cause ischemic stroke in young people and are associated with a high rate of stroke recurrence. Histopathological examination is crucial for clarifying the pathogenesis and mechanisms underlying the occurrence of carotid webs, although the mechanisms generally remain unclear. Here, we report a case of a symptomatic carotid web in a woman in her 50s who had a medical history of two ischemic strokes. She was diagnosed with a right carotid web and underwent carotid endarterectomy 18 days after the second stroke. Histopathological examination clearly revealed several phases of intimal hyperplasia. Furthermore, a thrombus attached to the carotid web showed invasion by fibroblasts and capillaries, and organization had begun. We presume that after the appearance of the carotid web, the thrombus formed by stagnant flow and became organized, causing the carotid web to grow and change in shape.

Prevalence and clinical features of carotid artery web in patients undergoing endovascular thrombectomy for acute ischemic stroke

PURPOSE

Carotid artery web (CaW) is a rare focal fibromuscular dysplasia that can lead to embolic strokes with large vessel occlusion. This condition can be effectively treated with endovascular thrombectomy (EVT). Our study aims to assess the prevalence of CaW among patients with acute ischemic stroke (AIS) who underwent EVT and to compare the clinical characteristics of CaW with other carotid artery pathologies.

METHODS

We enrolled consecutive patients with AIS who underwent EVT at a single medical center and two regional teaching hospitals in Taiwan from September 2014 to December 2021. We compared CaW with carotid dissection (CaD) and carotid large artery atherosclerosis (CaLAA) in terms of patient demographics and thrombus histological findings.

RESULTS

Of the 576 AIS patients who underwent EVT, four (mean age: 50 years) were diagnosed with CaW, resulting in a prevalence of 0.69%. Among these four patients, three experienced successful reperfusion after EVT and achieved functional independence (defined as a modified Rankin Scale score ≤2) three months post-stroke. Importantly, none of the CaW patients suffered a recurrent stroke within one year. Patients with CaW were younger than those with CaD or CaLAA, and exhibited fewer vascular risk factors. Additionally, CaW was associated with distal occlusion sites. The thrombus composition in CaW patients was similar to that in CaD patients.

CONCLUSIONS

In conclusion, CaW is a rare finding among Asian patients with carotid artery disease who undergo for AIS. It is more prevalent in younger patients with a limited number of vascular risk factors.

Carotid webs: a review of pathophysiology, diagnostic findings, and treatment options

A carotid web (CaW) is an atypical form of fibromuscular dysplasia characterized by a fibrous, shelf-like intimal flap originating from the posterior wall of the internal carotid bulb projecting into the arterial lumen. CaWs disturb normal blood flow and create stasis between the intimal reflection and the carotid wall, thereby promoting thrombogenesis and increasing the risk of downstream embolic strokes. Observational data have suggested that CaWs are associated with strokes with otherwise unknown etiology, particularly in young patients without other stroke factors, and stroke recurrence rates of symptomatic CaWs have been reported to be as high as 20% over 2 years. Despite its clinical importance, there are currently no clear guidelines on the management of CaWs. In this narrative review, we discuss the epidemiology, pathogenesis, pathophysiology, diagnosis, and treatment options for this under-recognized entity.

Imaging and clinical features of cervical artery web: report of 41 cases and literature review

This study investigated the imaging and clinical features of cervical artery web to improve disease diagnosis. Imaging and clinical data of 41 patients with cervical artery web were retrospectively analyzed and summarized in the context of the literature. Of the 8653 patients who underwent carotid computed tomography angiography (CTA) in the past 3 years at our hospital, 41 (0.47%) were diagnosed with cervical artery web. Among the 41 patients, there were 38 web structures in typical position, including 26 web structures located in the internal carotid artery and 12 in the proximal bifurcation of the common carotid artery. And the other three web structures were located outside carotid artery, including two in the subclavian artery and one in the vertebral artery. There were 47 web structures in 41 cases of cervical artery web; 35/41 (85.3%) were unilateral and 6/41 (14.7%) were bilateral. Among 41 patients, there were 20 patients who had cerebral infarction, 14 who experienced transient ischemic attack, 3 patients with cerebral hemorrhage; and 4 with other manifestations. Cervical artery web showed typical imaging features in the carotid CTA. Cervical artery web was most common in the internal carotid artery and at the bifurcation of the common carotid artery. It was also occasionally found in other rare artery such as vertebral and subclavian artery. Based on the various locations of web structure, we think it is necessary to rename carotid web as cervical artery web. Most of the attachment sites of the web structures were located in the posterior wall of the lumen, followed by the lateral wall; sites on the anterior wall were rare. Cervical artery web may be an underappreciated risk factor for stroke. And hypertension can increase the incidence of ischemic stroke in patients with cervical artery web.

Assessment of Recurrent Stroke Risk in Patients With a Carotid Web

Importance

A carotid web (CW) is a shelf-like lesion along the posterior wall of the internal carotid artery bulb and an underrecognized cause of young stroke. Several studies suggest that patients with symptomatic CW have a high risk of recurrent stroke, but high-quality data are lacking.

Objective

To assess the 2-year risk of recurrent stroke in patients with a symptomatic CW.

Design, Setting, and Participants

A comparative cohort study used data from the MR CLEAN trial (from 2010-2014) and MR CLEAN Registry (from 2014-2017). Data were analyzed in September 2020. The MR CLEAN trial and MR CLEAN Registry were nationwide prospective multicenter studies on endovascular treatment (EVT) of large vessel occlusion (LVO) stroke in the Netherlands. Baseline data were from 3439 consecutive adult patients with anterior circulation LVO stroke and available computed tomography (CT)-angiography of the carotid bulb. Two neuroradiologists reevaluated CT-angiography images for presence or absence of CW and identified 30 patients with CW ipsilateral to the index stroke. For these 30 eligible CW participants, detailed follow-up data regarding stroke recurrence within 2 years were acquired. These 30 patients with CW ipsilateral to the index stroke were compared with 168 patients without CW who participated in the MR CLEAN extended follow-up trial and who were randomized to the EVT arm.

Main Outcomes and Measures

The primary outcome was recurrent stroke occurring within 2 years after the index stroke. Cox proportional hazards regression models were used to compare recurrent stroke rates within 2 years for patients with and without CW, adjusted for age and sex. The research question was formulated prior to data collection.

Results

Of 3439 patients with baseline CT-angiography assessed, the median age was 72 years (interquartile range, 61-80 years) and 1813 (53%) were men. Patients with CW were younger (median age, 57 [interquartile range, 46-66] years vs 66 [interquartile range, 56-77] years; P = .02 and more often women (22 of 30 [73%] vs 67 of 168 [40%]; P = .001) than patients without CW. Twenty-eight of 30 patients (93%) received medical management after the index stroke (23 with antiplatelet therapy and 5 with anticoagulant therapy). 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).

Conclusions and Relevance

In this study, 1 of 6 patients with a symptomatic CW had a recurrent stroke within 2 years, suggesting that medical management alone may not provide sufficient protection for patients with CW.

Prevalence and site of predilection of carotid webs focusing on symptomatic and asymptomatic Japanese patients

OBJECTIVE

Carotid webs (CWs) have increasingly been recognized as a cause of recurrent ischemic stroke. However, the natural history and clinical course of CWs remain unclear. The authors aimed to clarify the prevalence, imaging features, and optimal treatment of CWs in a Japanese cohort study.

METHODS

A series of 444 consecutive Japanese patients who had undergone CTA of the head and neck between April 2011 and October 2016 was retrospectively reviewed. CW was diagnosed on CT angiograms as a membrane-like intraluminal filling defect along the posterior wall of the carotid bulb or the origin of the internal carotid artery (ICA) on oblique sagittal images and a corresponding thin septum on axial images.

RESULTS

Two patients with CWs were identified among 132 patients with suspected stroke. The prevalence of CWs among symptomatic patients with suspected stroke was 1.5%. The prevalence of asymptomatic CWs was 2.2% (7 of 312 cases). The CWs were located in the posterior wall of the carotid bulb in 7 patients and just distal to the ICA origin in 2 patients. There were no apparent differences in the location or lesion length between symptomatic and asymptomatic CWs. Four of the 7 asymptomatic CWs remained asymptomatic for at least 2 years of follow-up. Two patients with symptomatic CWs developed recurrent cerebral infarction and transient ischemic attack despite being on a regimen of oral antiplatelet agents, and carotid endarterectomy was performed as radical treatment. Patients with CWs were younger than controls (median age 55 vs 69 years, p = 0.003) and were less frequently male than controls (33% vs 72%, p = 0.025). CW cases showed significantly fewer common atherosclerosis risk factors than the control group (p < 0.05).

CONCLUSIONS

Although limited to CTA patients, this study reported on the prevalence and common site of CWs, focusing on symptomatic and asymptomatic Japanese patients. Extensive cross-sectional and prospective observational studies are warranted to elucidate the overall prevalence and natural history of CWs.

Carotid webs associated with ischemic stroke. Updated general review and research directions

Carotid web (CaW) is an intimal variant of fibromuscular dysplasia strongly associated with ipsilateral cerebral infarction. Although considered rare, it is a recent and increasing concern for physicians involved in stroke diagnosis and management. The present general review relies on a systematic literature analysis and aims to update readers on the latest knowledge in the field of symptomatic CaW (syCaW). CaW associated with ipsilateral cerebral infarction or transient ischemic attack has been identified in 189 patients. Ischemic strokes (IS) mostly occur in middle age (mean 46 years) and predominately in females (66%). The high frequency of African descendant patients among case reports and series (58%) suggests an ethnic susceptibility for CaW development. CaW features are characterised by a shelf-like intraluminal defect on contrast sagittal imaging, a linear defect that splits the lumen on axial section, a post-contrast stagnation rostral to the lesion and a frequent contralateral mirrored CaW (26.6%). An artery-to-artery embolism mechanism is widely accepted via CaW blood stasis, thrombus formation and clot fragmentation scattered by blood flow. Therefore, cerebral infarctions are often large related to a high proportion of proximal occlusion (62.5%). CaW confers a high rate of IS recurrence despite standard anti-platelet treatment that reaches 33.3% of patients prospectively followed with a median time to event of one year. Although no randomised therapeutic studies are available, surgery (n=39) or stenting (n=50) have been often proposed and seem to avoid recurrences. CaW clearly emerges as a cause of cryptogenic embolic stroke and should be systematically investigated in routine. A large number of points remain to be elucidated and CaW patients should be steadily included in registries and randomised therapeutic studies.

Carotid web: an occult mechanism of embolic stroke

The carotid web is a proposed stroke mechanism that may underlie cryptogenic stroke, particularly in younger patients without vascular risk factors. The web appears as a shelf-like projection into the lumen of the proximal cervical internal carotid artery without evidence of calcification. It is pathologically defined as intimal fibromuscular dysplasia. Altered haemodynamics distal to the web cause flow stagnation and remote embolisation of fibrin-based clots. It is best demonstrated and diagnosed on CT angiography (CTA) of the neck because of its ability to resolve calcium and create multiplanar reconstructions. Although they can be readily visualised on CTA, carotid webs may be missed or misinterpreted because they do not typically cause haemodynamically significant stenosis and can mimic arterial dissection, non-calcified atherosclerotic plaque and intraluminal thrombus. Options for management include antiplatelet therapy, carotid endarterectomy and carotid artery stenting. Modern management strategies for cryptogenic stroke include long-term cardiac monitoring, further investigation for structural cardiac disease and a diagnostic workup for arterial hypercoagulability, however, these strategies are not likely to capture the possibility of a carotid web. Carotid webs should be suspected in a young patient presenting with recurrent unihemispheric strokes particularly when conventional vascular risk factors are not present.

Survey of Current Management Practices for Carotid Webs

Background: Carotid webs are thick, fibrous intimal bands that appear as intraluminal shelf-like defects at the carotid bifurcation on vascular imaging. These lesions are a potential underrecognized cause of cryptogenic ischemic stroke. Although the recognition of carotid webs has increased, no evidence-based treatment guidelines are available. We surveyed subspecialists across multiple neurologic disciplines to assess the state of current clinical practice. Methods: An 8-question multiple-choice style survey of neurologists and radiologists assessed familiarity with this disease entity, preferred imaging modalities, and management strategies for asymptomatic and symptomatic (producing stroke) carotid webs. Responses were collected through SurveyMonkey software via anonymous responses to a posted survey link on the Society of Neurointerventional Surgery website in addition to invitation emails sent to colleagues in corresponding fields. Results: Of the 74 total respondents, 64% identified as neurointerventionalists. Respondents identified computed tomography angiography as the most commonly used imaging modality to place carotid webs in the differential diagnosis (57% of respondents' preference), while conventional digital subtraction angiogram was the preferred modality to confirm a web (54% of respondents' preference). Respondents preferred single and dual antiplatelet therapy to manage asymptomatic and acute stroke-producing carotid webs, while invasive treatment was most commonly sought for webs producing recurrent strokes. Conclusion: Familiarity with carotid webs varied across subspecialties. We found some consensus among respondents on the imaging modality preferred to identify webs, on asymptomatic carotid web management, and on recurrently symptomatic (multiple strokes) carotid web management. Less consistency was seen regarding preferences for confirmatory imaging and management of acutely symptomatic (initial stroke) carotid webs.

Neurointerventional management of carotid webs associated with recurrent and acute cerebral ischemic syndromes

BACKGROUND

A carotid web can be defined as an endoluminal shelf-like projection often noted at the origin of the internal carotid artery (ICA) just beyond the bifurcation. Diagnosis of a carotid web as an underlying cause of recurrent ischemic stroke is infrequent and easily misdiagnosed as an atheromatous plaque. Surgery has traditionally been used to resect symptomatic lesions while there is no enough evidence supporting medical therapy as the sole management. To our knowledge there is only one report about carotid artery stenting (CAS) as a definite management of carotid web and no previous reports of acute large-vessel occlusions undergoing mechanical thrombectomy in the setting of carotid web as the etiology.

CASE REPORT

We report two cases: The first presented with recurrent ischemic stroke in the same arterial territory and the other with an emergent left middle cerebral artery (MCA) occlusion that underwent endovascular mechanical thrombectomy in which initial computed tomographic angiograms (CTA) suggested carotid web etiologies. Following confirmation with digital subtraction angiography (DSA), both patients ultimately underwent endovascular carotid stenting instead of surgical resection for definitive carotid web treatment.

CONCLUSIONS

Carotid webs are a rare cause of ischemic stroke in young and middle-aged adults that can readily be identified by CTA. Endovascular management may include emergent mechanical thrombectomy for large-vessel thromboembolic complications, and for definitive treatment with carotid stenting across the carotid web as an alternative to surgical resection and medical management for secondary stroke prevention.

Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography

BACKGROUND AND PURPOSE

Carotid webs may cause recurrent ischemic stroke. We describe the prevalence, demographics, clinical presentation, imaging features, histopathology, and stroke risk associated with this under-recognized lesion.

MATERIALS AND METHODS

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. Using a prospective case series from April 2013 to April 2014, we describe the demographics, spectrum of imaging features on CTA, and histopathology of these carotid webs. From a retrospective analysis of patients at our center from May 2012 to April 2013 who had a baseline head and neck CTA followed by a brain MR imaging within 1-2 days of the CTA, we determine the period prevalence of carotid webs and the prevalence of ipsilateral stroke on imaging.

RESULTS

In the prospective series, the mean age was 50 years (range, 41-55 years); 5/7 patients were women. Recurrent stroke was seen in 5/7 (71.4%) patients with the carotid web; time to recurrence ranged from 1 to 97 months. Histopathology suggested a high probability of fibromuscular dysplasia. In the retrospective series, carotid webs were seen in 7/576 patients for a hospital-based-period prevalence of 1.2% (95% CI, 0.4%-2.5%). Two of these 7 patients had acute stroke in the vascular territory of the carotid web.

CONCLUSIONS

A carotid web may contribute to recurrent ischemic stroke in patients with no other determined stroke mechanism. Intimal variant fibromuscular dysplasia is the pathologic diagnosis in most cases. The prevalence of carotid web is low, while the optimal management strategy remains unknown.

Internal Carotid Artery Web: Doppler Ultrasound with CT Angiography correlation

We present a case of an internal carotid web, detected on duplex ultrasound and confirmed by CT angiography. To our knowledge, this is only the third reported ultrasound case in the imaging literature. This vascular abnormality can cause a clinically significant carotid stenosis and is a risk factor for recurrent embolic cerebrovascular events. Due to small size and poor awareness among radiologists, carotid webs are often under-diagnosed on non-invasive imaging modalities. Improved awareness including knowledge of salient imaging features is useful as early diagnosis leading to appropriate intervention can eliminate the risk of future cerebrovascular events.

Percutaneous transluminal coronary angioplasty in a two-month old with coronary stenosis presenting as congenital cardiomyopathy: acute results and intermediate follow-up

Congenital or nonsurgically acquired obstructive coronary artery disease in infancy is exceedingly rare, and previous reports of catheter-based therapies in very young patients have been solely in patients having undergone arterial switch or other cardiovascular surgical procedures. We describe a previously unreported cause for ventricular dysfunction and heart failure in an infant, isolated congenital circumflex coronary artery stenosis, and successful treatment with percutaneous transluminal coronary angioplasty. Technical considerations, immediate results, and 3-year follow-up are provided.

Web-like malformation of the carotid artery and multicystic encephalomalacia

Multicystic encephalomalacia and hydranencephaly lie within a spectrum of brain lesions linked to ischemic cerebral damage. Causes include vascular malformation, thrombosis, embolism, infection, and toxins. We describe an infant with multicystic encephalomalacia associated with a peculiar web-like malformation of the right common carotid and left subclavian arteries. We postulate that this luminal bridging is a congenital malformation resulting from defective canalization of the medium-sized blood vessels but could represent organized and recanalized thrombi, the etiology of which remains unknown.