Carotid web (CW) was first described in 1968 as a focal shelf of tissue in the posterior wall of the carotid bulb with the absence of calcification or atherosclerosis [8]. It has been referred to as an atypical variant of fibromuscular dysplasia, characterized by tunica intima hyperplasia and tending to expand into the arterial lumen [6]. The etiology of CW is still uncertain, but some factors have already been proposed in the literature, including genetic factors, chronic vascular injury, hormonal factors, contraceptive pills, and trophoblastic vascular abnormality [2,6]. Despite being a rare disease with an incidence of 0.62% [1,5,9], this is already demonstrated as a high-risk lesion with a high rate of stroke recurrence (29%) [4]. The disruption of normal laminar blood flow distal to the CW is the source of thrombus formation and the stroke mechanism [3]. Corroborating with this theory, in 67% of cases thrombus is visualized on the web [7]. All descriptions demonstrate the location in the carotid bulb but one case report demonstrating the presence in the common carotid artery [2] was described as presented in our case.

A patient in their 30s with no risk factors for cardiovascular diseases had a history of having had multiple ischemic strokes all on the left hemisphere. During the first investigation a digital subtraction angiography (DSA) was done with no carotid bulb abnormalities with thrombus on the left middle cerebral artery, anterior cerebral artery, and the external carotid artery (Fig.1). He had no cardiac abnormalities, and all the coagulopathy investigation was negative (factor V Leiden; prothrombin g20210A; protein C and S deficiency; antithrombin deficiency; homocysteine and antiphospholipid antibodies; anti lupic antibody) but received anticoagulation with warfarin for 5 months with the international normalized ratio between 2-3. He had stroke recurrence and the possibility of vasculitis was suspected due to a cerebrospinal fluid pleocytosis and he received cyclophosphamide for 3 months. He had another stroke and was admitted to our hospital for further investigation.

During this investigation, a common CW was diagnosed on the computed tomographic angiogram (CTA) (Fig. 2) and was confirmed by the DSA (Fig. 3). Thrombus was visualized on the web position and a mechanical thrombectomy was done. The aspiration technique was applied to “clean” the web and after that, an angioplasty was done to treat the common CW with double protection for distal embolization (distal embolic protection - Filterwire EZ Embolic Protection System (Boston Scientific, MA USA) and a balloon guide catheter-FlowGate2 (Stryker Neurovascular Fremont, California USA) ). A Wallstent (Boston Scientific, MA USA) was delivered (Fig. 4). The patient received double antiplatelet therapy (aspirin and clopidogrel) for 3 months.

After the treatment, the patient had no further ischemic events and had a National Institute of Health Stroke Scale of 1 at the 3 months follow-up besides all the ischemic events prior to the treatment.

Carotid bulb web, although rare and not well known, is a well-established etiology of recurrent stroke in young patients, with a recurrence rate of 29% [4]. Diagnosis can be challenging in classic cases of CW. This becomes even more challenging when presented in an atypical location, such as the common carotid artery. In young patients with ischemic stroke, the investigation must be exhaustive in search of the etiology of the stroke. In the young population (under 55 years old), the prevalence of CW is 37% in undetermined stroke etiology [4]. The best method to make the diagnosis is with the CTA which can help to identify the presence of thrombus and atherosclerotic changes. In this case, we used the XperCT tool from Allura Xper FD20 x-ray system (Phillips, Netherlands) during the DSA to better demonstrate the web (Fig. 4). This tool might increase our CW diagnostic power during DSA and help to make the differential diagnostic.

As in our case, anticoagulation may not decrease the risk of stroke recurrence in long-term follow-up [4]. Although some articles demonstrate that carotid artery stenting (CAS) is safe and effective in preventing stroke recurrences [4] the best therapeutic strategy (antiplatelet therapy, anticoagulation or interventional treatment - carotid endarterectomy or CAS) for treating the web is still a point of debate [3]. After the CAS treatment, the patient had no further recurrences of stroke and was maintained for 3 months with dual antiplatelet therapy.

Our experience can provide the following insights: Firstly, in young patients (under 55 years old), the CW should be thoroughly investigated during a stroke. Secondly, the web might be demonstrated on the common carotid artery. Thirdly, long-term anticoagulation may not effectively prevent recurrent strokes associated with CW. Finally, CAS could be a viable treatment option for CW.

CW is an important source of thrombus with a high rate of stroke recurrence and it might be present not only on the carotid bulb but also on the common carotid artery as we described in this case. This diagnosis can only be confirmed by a histopathologic study, but we demonstrated many web characteristics in our patient with the CW.