Introduction: Carotid web is an intraluminal projection in the posterior aspect of the internal carotid bulb and represents an intimal variant of fibromuscular dysplasia. It may serve as a source of thrombus formation leading to embolic strokes and has been poorly described. We aim to study the prevalence of carotid webs among patients with cryptogenic ischemic strokes (CIS).
Methods: This was a retrospective analysis of patients aged 18-60 years who presented to two comprehensive stroke centers with CIS (TOAST criteria) and underwent neck CTA, from January 2016 to May 2017. Carotid web was defined as a shelf-like projection with linear/smooth filling on the posterior bulb without superimposed atherosclerosis (defined as adjacent calcifications or wall thickness >3mm). CTAs were reviewed by a neurointerventionist blinded to clinical and other radiological studies. CIS patients with carotid webs (with strokes within the vascular territory) were then compared to the remaining CIS patients.
Results: Of 162 CIS patients within the study period, 43 patients met the inclusion criteria. Thirteen patients had carotid webs (29.5%), 10 of whom had a stroke in the same vascular territory as the web (22.7%). Median length of the intraluminal web projection was 1.6[1.5-2.0]mm. Age, gender and comorbidities were similar between the patients with stroke within the carotid web territory (n=10) and the remainder of the CIS patients (n=33)(Table). None of the patients with ischemic stroke in the carotid web territory were white, while 90% were black (compared to 18% and 74% of the 43 CIS patients, respectively). The NIHSS in the carotid web group was 14.2 [7.9-20.5] as compared to the other CIS arm 10.1 [3.3-16.9]; p=0.09.
Conclusion: Carotid webs are an under-recognized etiology in CIS affecting the young. Routine and careful vascular imaging analysis of the carotid bulb in young CIS patients is indicated. Further studies are needed.