|Year : 2022 | Volume
| Issue : 1 | Page : 48-50
A case report of carotid web: A hidden fiend of stroke
GG Sharath Kumar, Chaitra Parameshwara Adiga, Lakshmikanth N Goolahally, Prakash P Iyer
Department of Radiology, Apollo Hospitals, Bengaluru, Karnataka, India
|Date of Submission||20-Oct-2021|
|Date of Decision||07-Dec-2021|
|Date of Acceptance||10-Dec-2021|
|Date of Web Publication||24-Jan-2022|
Chaitra Parameshwara Adiga
Department of Radiology, Apollo Hospitals, Sheshadripuram, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
Web at the carotid bulb is overlooked in routine practice. Carotid web is to be thought of as the causative factor in the absence of major risk factors or in cryptogenic stroke and familiarity of this entity is important among the radiologists and treating physicians. We report a case of recurrent ischemic stroke in young man who presented with limb weakness despite best medical therapy without any risk factors. There was left middle cerebral artery infarct on computed tomography (CT) scan. The evaluation of the cause of his stroke revealed carotid web on CT angiogram which was further confirmed by digital subtraction angiography and treated by carotid stenting to prevent further episodes of stroke.
Keywords: Carotid web, computed tomography angiogram, large vessel occlusion, recurrent stroke
|How to cite this article:|
Sharath Kumar G G, Adiga CP, Goolahally LN, Iyer PP. A case report of carotid web: A hidden fiend of stroke. Apollo Med 2022;19:48-50
| Introduction|| |
Carotid web, a potential risk factor of large vessel occlusion is a thin linear membrane at the posterior wall of carotid bulb. It is not too rare; however, it is an unrecognized entity which is commonly missed in day-to-day practice. General radiologists and fellows come across stroke patients more than neuroradiologists in developing countries. It is very important to identify and treat this entity as it may increase the rate of progression of acute ischemic stroke in a short interval of time. It is one of the treatable and/or preventable causes of stroke. Repeated stroke episodes and strokes in young should rise a possibility of carotid web. Computed tomography angiogram (CTA) and digital subtraction angiography (DSA) are the imaging modalities of choice for the diagnosis and further management of this occult culprit.
| Case Report|| |
A 47-year-old man came to the emergency department with a history of right lower limb weakness within 3 h. He was diagnosed to have acute left middle cerebral artery (MCA) infarct on computed tomography (CT) [Figure 1] at a secondary health care facility and was referred to our center for further management. He had repeated episodes of transient ischemic attacks (TIA) in the past with complaints of mild weakness and numbness in the right upper and lower limbs lasting for few minutes to an hour each and was on single antiplatelet drug named aspirin for the same prescribed by a general practitioner outside. Though he fits into the stroke in young, he was not evaluated further. CT of the brain without angiogram was the only investigation he had undergone before his entry to our center. A note of National Institutes of Health Stroke Scale of 16 and power of right upper limb of 1/5 was made at his arrival and was immediately thrombolysed with intravenous alteplase of 0.9 mg/kg with 10% of the dose given as initial bolus and the rest as infusion over the next 60 min. Complete cardiac evaluation including transthoracic and transesophageal echocardiography and 24 h holter monitoring were normal. CTA performed to look for the cause of stroke, showed a small smooth shelf like intraluminal protrusion from the posterior wall of left carotid bulb suggesting a carotid web [Figure 2]a. Differential diagnoses of dissection flap and atheromatous plaque were ruled out as these conditions are commonly seen more distal along the internal carotid artery and with irregular borders with or without calcifications. Volume rendering technique CT image shows post web dilatation [Figure 2]b. There was left M1 occlusion for which he was simultaneously shifted to the cath-lab to perform mechanical thrombectomy. DSA was performed. It confirmed carotid web showing significant contrast turbulence followed by stasis in arterial and venous phases [Figure 3]a and [Figure 3]b and also complete recanalization of the left MCA territory. As there was recanalization, no further intervention was done at this setting. According to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, the luminal stenosis at the region of carotid web was approximately 20%–30%. He was discharged and prescribed with dual antiplatelet drugs, i.e., 75 mg of clopidogrel and 150 mg of aspirin daily. After a month of follow-up, there was mild residual right lower limb monoplegia with modified Rankin score of one. Two months later, he had an episode of TIA with complaints of right upper limb weakness and dysarthria lasting for few minutes for which magnetic resonance imaging brain was performed. It did not reveal any acute infarct. There were further similar recurrent episodes of TIAs. The patient was then advised for interval endovascular carotid stenting to prevent recurrent/further episodes of stroke. He underwent left carotid artery stenting after 4 months. Post stenting check angiogram was unremarkable with adequate forward flow without in-stent thrombosis [Figure 3]c. He withstood the procedure well and postoperative period was uneventful. He was discharged with dual antiplatelet therapy namely 75 mg of clopidogrel and 150 mg of aspirin daily for 6 months, from then on, continuation of aspirin daily indefinitely. He is on regular follow-up and no further stroke has been documented till date.
|Figure 1: Computed tomography axial section of the brain shows acute infarct in the left fronto-temporal lobe (arrow)|
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|Figure 2: Sagittal reformatted computed tomography angiogram of the neck reveals carotid web (arrow) (a), volume rendering technique computed tomography image of the neck vessels showing post web dilatation (arrow) (b)|
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|Figure 3: Digital subtraction angiography showing stasis of contrast distal to the left carotid bulb (arrows) in arterial (a) and venous phases (b). Check angiogram shows stent across the web (arrow) (c)|
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| Discussion|| |
Carotid web, a variant of fibromuscular dysplasia, is described as a fibrous intimal thickening at the carotid bulb along its posterior wall. Carotid webs pose a potential risk of ipsilateral ischemic stroke, due to thrombus development associated with blood flow disruptions around the web. It may be detected incidentally on imaging. In this case, the patient had repeated episodes of limb weakness without dense hemi/paraplegia before his admission to our center. The cause of his TIA was not evaluated till then. Carotid web acts as a nidus causing recurrent ischemic strokes especially in young without any comorbidities. Pooling and stagnation of the blood distal to the site of the web increases the risk of thrombus formation causing large vessel occlusion by dislodging the thrombus distally., Recognizing and diagnosing this condition is challenging. TIAs are the most common presentation in patients with carotid webs. Although ultrasound of the carotids may reveal a small wedge-shaped echogenic area at carotid bulb without any significant flow-limiting stenosis. CTA is the initial diagnostic imaging modality which shows a smooth shelf-like filling defect along the posterior wall of the carotid bulb. This finding on CTA warrants DSA for the confirmation of the web. Although the role of MR angiogram is limited as compared to CTA due to its lesser spatial resolution compared to CTA, dephasing artifact, and CTA being readily available, a recent study has shown that MR angiogram yields few key facts with respect to the vessel wall mechanics, composition and blood flow in carotid webs. Although the luminal stenosis is lesser in carotid web according to the NASCET criteria, the hemodynamic disturbances are of a higher degree compared to mild to moderate carotid atheromatous disease resulting in thrombus formation. On DSA, stasis of contrast distal to the web is pathognomonic of this entity. The treatment includes endovascular carotid stenting or endarterectomy for prevention of multiple or recurrent strokes and endovascular stenting being commonly preferred among the two especially those who have failed medical management. In our case, though the patient was on dual antiplatelet therapy, the patient had recurrent episodes of TIAs. In such cases, intervention plays a major role for the prevention of stroke in future.
In conclusion, carotid webs are an increasingly recognized ischemic stroke etiology in young patients despite being commonly missed or misdiagnosed. Awareness of the carotid web and its imaging characteristics is essential and is increasing among the subspecialists but lacking among the general radiologists/fellow residents. DSA serves as the gold standard tool for the diagnosis and endovascular stenting being used commonly for the treatment.
- Carotid web needs to be considered in patients with cryptogenic stroke or recurrent TIAs without any high-risk factors
- DSA serves as the gold standard imaging tool for the diagnosis
- Treatment includes neurointerventional management by endovascular stenting of the carotid artery or endarterectomy.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]