Abstract DP133: Morphologic Features of Carotid Webs and Risk of Ischemic Stroke

Introduction: Carotid webs (CWs) are shelf-like projections arising from the posterior wall of the carotid bulb that may cause ischemic stroke, particularly in younger individuals without traditional vascular risk factors. We examined morphologic features of CWs on CT angiography (CTA) associated with risk of stroke or TIA. Methods: We retrospectively reviewed neck CTA imaging in adults with “web” mentioned in the radiology report from January 2021 to June 2024, excluding those with prior intervention on the same carotid artery, across 2 health systems. CWs were confirmed based on published diagnostic criteria. Morphologic features were independently measured by 2 experienced raters blinded to clinical history. Assessed features included web length, thickness, base width, angle relative to vessel wall, distance to bifurcation, web-to-bulb ratio, percent luminal stenosis, and presence of calcification in the carotid bifurcation (not on the web) (Table 1). The mean of the readers’ measurements was used for analysis. CWs were classified as symptomatic if an acute ischemic stroke or TIA occurred exclusively in the ipsilateral carotid territory without an alternative stroke etiology. Stepwise multivariable logistic regression modelling was used to identify baseline and morphologic variables associated with symptomatic CW. Variables with a p-value <0.20 in the univariable analyses were included in the model. Results: A total of 229 webs were identified among 214 included patients (mean age=55.8±15.6 years, 68% female), of which 24 (11.2%) were symptomatic CWs. Baseline demographics and vascular risk factors were similar between the groups (Table 2). Symptomatic CWs were longer (median IQR, 2.9 2.3-3.9 vs. 2.3 2.0-2.8; OR:1.57, 95% CI:1.11-2.22), thicker (1.6 1.2-2.0 vs. 1.2 1.0-1.5; OR:1.62, 95% CI:1.01-2.60) and had a larger base width (2.4 1.7-3.3 vs. 1.8 1.5-2.6; OR;1.28, 95%CI:1.00-1.65) compared to asymptomatic webs (Table 3). In multivariable analysis, only CW length remained independently associated with symptomatic status (OR:1.57 per mm, 95% CI:1.11-2.22; AUC: 0.66). Conclusions: Symptomatic CWs tend to be longer, thicker, and have a larger base width than asymptomatic webs, with length independently predicting symptomatic presentation. These morphologic features may inform risk stratification and guide treatment decisions.