Detection of Carotid Webs by CT Angiography, High-Resolution MRI, and Ultrasound

Breakthrough of dual-phase CT angiography features of carotid web and its correlation with ischemic stroke

PURPOSE

To investigate the diagnostic value of dual phase CT angiography (CTA) in carotid web and its correlation with ischemic stroke.

METHODS

The imaging data of 726 patients with cervical CTA from January 2015 to November 2019 in Taizhou People's hospital were retrospectively and consecutively analyzed. A total of 16 patients with 23 carotid webs were obtained. The location, morphology and clinical data of 16 patients were observed. Carotid web was identified by two experienced radioimaging experts according to the characteristics of a thin intraluminal filling defect along the posterior wall of the carotid bulb on sagittal CTA and a septum structure in arteries on axial CTA.

RESULTS

In the arterial phase, 23 carotid webs in 16 patients showed membrane like separation in the lumen of the posterior wall of the carotid bulb, and one web extended into the internal and external carotid arteries in a "Y" shape. There were 9 males and 7 females. In venous phase, 16 carotid webs showed linear enhancement, and 15 sites showed delayed emptying of contrast medium at the lateral margin. Five patients were acute or chronic ischemic stroke. The kappa coefficient for interobserver agreement in diagnosing carotid web was 0.79.

CONCLUSION

Dual-phase CTA is effective and reliable method to identifying carotid webs, which may be associated with ischemic stroke.

Recurrent stroke shortly after mechanical thrombectomy secondary to carotid web: A case report

RATIONALE

Carotid web, a known source of thrombus for embolic stroke, presents a considerable risk of stroke recurrence. While case reports have demonstrated the safety and effectiveness of mechanical thrombectomy in treating carotid web-related stroke, the need for concurrent carotid artery stenting to prevent recurrent stroke immediately after thrombectomy remains unclear. This study aims to underscore the importance of immediate carotid artery stenting in preventing recurrent stroke following mechanical thrombectomy in patients with carotid web-related stroke.

PATIENT CONCERNS

A 43-year-old woman with acute onset of left limb weakness and slurred speech within 3 hours was admitted to the emergency department.

DIAGNOSES

Computed tomographic angiography confirmed the M1 segment occlusion of the right middle cerebral artery.

INTERVENTIONS

The patient received intravenous thrombolysis in the local hospital and mechanical thrombectomy in our stroke center.

OUTCOMES

Three days post-mechanical thrombectomy, there was a sudden exacerbation of her neurological deficit symptoms. A reexamination via computed tomographic angiography revealed a re-occlusion in M1 segment of the right middle cerebral artery, despite the implementation of stringent anticoagulation therapy for carotid web-related stroke.

LESSONS

Stroke patients with carotid web had a high risk of stroke recurrence and it was necessary to conduct carotid artery stenting to prevent stroke recurrence secondary to the carotid web immediately after mechanical thrombectomy.

[A case of recurrent stroke with carotid-web despite dabigatran treatment successfully treated by carotid endarterectomy]

We present a case of a 41-year-old female presenting with recurrence of ischemic stroke on subtherapeutic doses of dabigatran. She had a history of embolic stroke of undetermined sources at the age of 40, and underwent implantable cardiac monitor implantation and had started dabigatran. One year after the first ischemic stroke, she presented with sudden dysarthria and left hemiparesis and was admitted to our hospital. An MRI of the head revealed acute cerebral infarction in the right corona radiata, and an MR angiography revealed right M2 occlusion. Cervical 3D-CTA revealed a protruding structure on the posterior wall of the carotid artery bulb, which was diagnosed as carotid web. She underwent carotid endarterectomy, and the specimen was pathologically confirmed to be vascular malformation due to fibromuscular dysplasia.

Ultrasound characteristics of carotid web

BACKGROUND AND PURPOSE

Carotid web (CaW) is a cause of recurrent ischemic stroke that remains underdiagnosed using Duplex ultrasound (DUS). Improved methods and description of its ultrasound's features could allow better detection of CaW. Ultrasound microflow imaging (MFI) is a blood flow imaging technique sensitive to slow flow that could increase CaW detection. This study aimed to describe ultrasound features of CaW using B-mode imaging and MFI.

METHODS

In a retrospective monocentric study, patients with CaW on CT angiography who underwent DUS examination of carotid arteries were included. DUS was performed by two nonblinded experienced neurosonologists. The specificity of CaW ultrasound features was evaluated using a group of patients with carotid atherosclerotic plaque (AP).

RESULTS

Twenty-four patients with CaW were included. Mean age (standard deviation) was 48 years (11). Seventeen (71%) were females. Fifteen (63%) CaWs were symptomatic. MFI was available for 22 patients. B-mode imaging demonstrated the characteristic CaW appearance in 19/24 (79%) patients as a protruding triangular iso-hypoechoic lesion on longitudinal view. CaW were detected on axial view in only 9/24 (38%) patients. MFI displayed slow blood flow above CaW during systole and allowed it delineation, appearing as a thin triangular endoluminal defect in 18/22 (82%) cases. Based on MFI and B-mode, 21/22 (95%) CaWs were visible, including three CaWs only with MFI. These ultrasound features were not found among 24 patients with AP.

CONCLUSION

We report the ultrasound features from a series of 24 CaW. The use of MFI in addition to B-mode imaging improved the detection rate of CaW.

The Value of Contrast-Enhanced Ultrasound in the Evaluation of Carotid Web

Objectives

The purpose of this study was to investigate whether contrast-enhanced ultrasound (CEUS) is more advantageous than conventional ultrasound in the diagnosis of carotid web (CaW) and to compare the clinical characteristics of patients in different age groups.

Methods

Seventeen patients admitted to the hospital from October 2019 to December 2021 were included in our study. Patients were initially diagnosed with CaW using digital subtraction angiography (DSA), and conventional ultrasound and CEUS were completed. Baseline patient data were analyzed and compared between the <60 years old CaW group and the ≥60 years old CaW group to explore the differences between the two groups. Then, comparing the accuracy of conventional ultrasound and CEUS.

Results

A total of 17 CaW patients participated in this study, including 4 female patients (23.5%) and 13 male patients (76.5%), with an average age of 59.41 (±10.86) years. There were 9 patients (52.9%) with left CaW and 8 patients (47.1%) with right CaW. Acute ischemic stroke (AIS) occurred in 14 patients (82.4%). Thrombosis occurred in five of 17 patients (29.4%). There was a significant statistical difference about the thrombosis between the <60 years old CaW group and the ≥60 years old CaW group [<60 years group: 0 (0%), ≥60 years group: 5 (62.5%), P = 0.005]. Seven patients (41.2%) received medical management, nine patients (52.9%) had carotid artery stenting (CAS), and one patient (5.9%) had carotid endarterectomy (CEA). None of the patients had recurrent stroke during the follow-up period. The diagnostic rate of CaW and thrombus by CEUS was higher than that by conventional ultrasound, and there was a significant statistical difference in the diagnosis of thrombus between CEUS and conventional ultrasound (χ2 = 4.286, P = 0.038).

Conclusions

CEUS may have a higher diagnostic accuracy for CaW with thrombosis, and it has a higher clinical application prospect.

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 stent for the prevention of recurrent stroke: Case report and literature review

Carotid web has been identified as one of the missed causes of recurrent stroke. The diagnosis and management of such cases impose a challenge to medical practitioners. This etiology should be kept in mind, especially in case of recurrence of stroke in a similar cerebral territory.

Delayed Thrombus on Carotid Web: Case Report With Escalation of Treatment

Carotid artery web is an underrecognized source and is found in about 1-2% of patients with acute ischemic stroke. Although, first described four decades ago, optimal therapy for carotid web is not yet known. Carotid stenting and endarterectomy are increasingly used for carotid web treatment, given its definitive treatment and avoiding the complications associated with anticoagulation. The case reported here is of an ischemic stroke secondary to a mobile thrombus on a carotid web evident on CT angiography and successful definitive treatment with delayed carotid wall stent placement. In young patients who have a diagnosis of ischemic stroke, the carotid web should be on the differential and adequate neuroimaging with either CTA or DSA should be pursued.

Assessment of association between the carotid web and dissection in spontaneous internal carotid artery dissection patients using vessel wall MRI

BACKGROUND

Internal carotid artery dissection (ICAD) is the major cause of ischemic stroke in young to middle-aged people. Recognition of predisposing factors may facilitate in early individual risk prediction and expand treatment.

PURPOSE

To evaluate the association between a carotid web and dissection in patients with ICAD using vessel wall magnetic resonance imaging (VW-MRI).

MATERIAL AND METHODS

A retrospective study was conducted of 223 patients who underwent VW-MRI. Of these patients, 58 patients with craniocervical artery dissection (CCAD) (33 ICAD and 25 vertebrobasilar artery dissection [VBAD]) were included. The control group (n = 165) consisted of patients without arterial dissection who had undergone VW-MRI . The presence of a carotid web in the posterior aspect of carotid bulb was recorded. The distance between the carotid web and start of dissection in ICA was recorded.

RESULTS

The presence of a carotid web showed a significant difference between the ICAD, VBAD, and control groups (19 [57.6%] vs. 5 [20%] vs. 36 [21.8%], respectively; P < 0.001). In multi-nominal analysis, the presence of a carotid web showed a significant difference between the ICAD and VBAD groups and the ICAD and control groups (P < 0.05), with odds ratios of 5.41 (95% confidence interval [CI]=1.634-17.973) and 4.81 (95% CI=2.176-10.651), respectively. Out of 19 ICAD patients with carotid web, 16 had occurrence of dissection in the C1 segment of the ICA with a mean distance of 1.91 ± 1.71 cm from the carotid web.

CONCLUSION

Presence of a carotid web was more frequent in patients with ICAD. The carotid web may be one of the predisposing factors for development of dissection in patients with ICAD.

Embolectomy of acute embolic stroke associated with ipsilateral carotid web: a case report and literature review

A carotid web is a thin intraluminal protrusion located in the posterolateral wall of the carotid bulb, which might be a risk factor for cryptogenic stroke. The mechanism of ischemic stroke caused by carotid web is still unclear, but it might be related to hemodynamic changes distal to the web, resulting in flow forces and remote embolization of fibrin-based clots. The diagnosis of a carotid web mainly depends on carotid artery imaging examinations. The main therapeutic strategies include medical treatment with oral antiplatelet agents and anticoagulants, and operative treatment, such as carotid endarterectomy and carotid artery stenting. Few cases of acute large-vessel occlusion undergoing mechanical thrombectomy in the setting of carotid web as the etiology have been reported. We report here a case of a 37-year-old woman who underwent stent retriever embolectomy after acute ischemic stroke. Carotid artery imaging examinations, including digital subtraction angiography and magnetic resonance imaging, and pathology showed that a carotid web was located at the proximal right internal carotid artery. We also discuss the clinical pathophysiological and imaging features, and the treatment of carotid web as described in the currently available literature.