Carotid webs associated with ischemic stroke. Updated general review and research directions.

Carotid web (CaW) is an intimal variant of fibromuscular dysplasia strongly associated with ipsilateral cerebral infarction. Although considered rare, it is a recent and increasing concern for physicians involved in stroke diagnosis and management. The present general review relies on a systematic literature analysis and aims to update readers on the latest knowledge in the field of symptomatic CaW (syCaW). CaW associated with ipsilateral cerebral infarction or transient ischemic attack has been identified in 189 patients. Ischemic strokes (IS) mostly occur in middle age (mean 46 years) and predominately in females (66%). The high frequency of African descendant patients among case reports and series (58%) suggests an ethnic susceptibility for CaW development. CaW features are characterised by a shelf-like intraluminal defect on contrast sagittal imaging, a linear defect that splits the lumen on axial section, a post-contrast stagnation rostral to the lesion and a frequent contralateral mirrored CaW (26.6%). An artery-to-artery embolism mechanism is widely accepted via CaW blood stasis, thrombus formation and clot fragmentation scattered by blood flow. Therefore, cerebral infarctions are often large related to a high proportion of proximal occlusion (62.5%). CaW confers a high rate of IS recurrence despite standard anti-platelet treatment that reaches 33.3% of patients prospectively followed with a median time to event of one year. Although no randomised therapeutic studies are available, surgery (n=39) or stenting (n=50) have been often proposed and seem to avoid recurrences. CaW clearly emerges as a cause of cryptogenic embolic stroke and should be systematically investigated in routine. A large number of points remain to be elucidated and CaW patients should be steadily included in registries and randomised therapeutic studies.