Systematic review and meta-analysis of ipsilateral and contralateral carotid web prevalence in embolic supratentorial strokes of undetermined source.

OBJECTIVES: A carotid web isdefined as an abnormal shelf-like projection of intimal fibrous tissue into the carotid bulb. Its presence may be an under-recognised source of embolic stroke of undetermined source (ESUS). The aim of this study was to investigate its prevalence in previously reported studies. MATERIALS AND METHODS: A systematic literature review of Pubmed, EMBASE, and Scopus was conducted up until the 4/12/2021 using variations of the search terms - 'carotid web' and 'ischemic stroke'. Inclusion criteria were studies reporting carotid web prevalence in an ESUS cohort aged >18 years with adequate imaging. Secondary measures such as age, gender, ethnicity, and laterality were recorded. A meta-analysis of proportions was used to summarise the prevalence of webs along with a random-effects model to calculate the relative risk of ipsilateral and contralateral webs in ESUS. RESULTS: The initial search yielded 361 articles, with 11 remaining post the inclusion and exclusion criteria. A meta-analysis of allage groups yielded a total carotid web prevalence among patients with stroke of unknown cause of 9.58 % (95 % CI 5.62 - 15.85). Carotid webs were more often detected in females (76.5 % ± 22.3 %), and in those of African heritage (58 % ± 39 %). In comparison with patients without an ischemic stroke, there was a significant association found for an ipsilateral carotid web (risk ratio of 2.74 (95 % CI: 2.14 - 3.51)) but no association found for contralateral webs (risk ratio of 1.50 (95 % CI: 0.94 - 2.40)). CONCLUSION: The prevalence of ipsilateral carotid webs associated with ESUS is substantial, and may be more common in females and in individuals of African descent.