Current Understanding and Gaps in Research of Carotid Webs in Ischemic Strokes: A Review.

Importance: A succession of research has explored the linkage between carotid webs (CaWs) and ischemic strokes. Imaging and pathologic analysis have defined CaW as an intimal variant of fibromuscular dysplasia, which appears as a shelflike lesion on the posterior aspect of the carotid bulb, more specifically at the origin of internal carotid artery. Reported findings of carotid webs in young patients with recurrent ischemic strokes without an otherwise determined cause have raised questions about the mechanism, natural history, and need for intervention. This review addresses the current understanding of CaW and highlights findings that prompt further investigation into this unique vascular entity as a modifiable stroke risk factor. Observations: Imaging analysis demonstrates hemodynamic disturbance in the presence of CaWs. The protuberant shelflike structure creates a pocket therein that may subsequently lead to local thrombosis and cerebral embolism. Computed tomographic angiography is an accurate and often used noninvasive diagnostic modality. Although treatment paradigms have not been systematically evaluated, antiplatelet monotherapy may not be sufficient to reduce recurrent ischemic events in the small series of patients with stroke and symptomatic CaWs. Conclusions and Relevance: The limited clinical data on CaWs, although complicated by selection bias, suggest an increased prevalence of these vascular entities in cerebral ischemic events among patients younger than 60 years. Imaging suggests CaW to be a possible nidus for cerebral thromboembolism. Physicians should consider CaW as a cause of stroke in younger patients with anterior circulation ischemic strokes of an otherwise undetermined cause. Treatment options in CaWs with ischemic strokes have not been extensively investigated. Multicenter observational studies evaluating the natural history of CaW are warranted.