Carotid Webs in Cryptogenic Ischemic Strokes: A Matched Case-Control Study

Background: Young individuals with symptomatic carotid webs may be predisposed to ischemic strokes. However, evidence remains scarce. This investigation reports the frequency of carotid webs among patients with cryptogenic strokes compared to a control group. Methods: Consecutive cryptogenic ischemic strokes and trauma patients were identified. Additional inclusion criteria required age 18-60 years and availability of head/neck computed tomography (CT) angiography. CT angiogram (CTA) neck images were evaluated independently by 2 fellowshiptrained specialists. A carotid web was defined by a shelf-like, linear filling defect in the posterior internal carotid artery bulb. Results: Of 1877 patients presenting with ischemic strokes in 2015-2017, 165 were diagnosed with cryptogenic strokes, 51 of whom met the inclusion criteria of age and CTA availability. Fifty one trauma cases were matched for age and sex. After imaging analysis, 13 carotid webs (25%) were identified in the 51 cryptogenic stroke group versus 0 (0%; P < .001) in trauma subjects. Thirty-nine of the 51 cryptogenic ischemic stroke patients were found with carotid anterior distribution infarcts, of which 9 (23%) were found with ipsilateral carotid webs. There were more proximal large vessel occlusions in the cryptogenic patients with carotid webs, compared to those without (P = .04). All carotid webs led to less than 30% degree of stenosis. Conclusions: Carotid webs were found at a significantly higher frequency in patients with cryptogenic ischemic strokes compared to controls, indicating a potentially thrombogenic nature of these lesions in young patients. Additionally, intracranial large vessel occlusions were more common in patients with symptomatic carotid webs, presenting with ipsilateral strokes.