Carotid Web Case Report: A Carotid Bifurcation Disorder Causing Stroke Without Localised Significant Stenosis

A 33-year-old gentleman presented to the Emergency Department with headaches and vertigo following neck manipulation with a chiropractor and was discharged following an unremarkable CT. Three weeks after the initial presentation, the patient re-presented within 24 h of a secondary neck manipulation, experiencing dysphasia and dysarthria.

An MRI demonstrated an embolic infarct, and further investigations were requested. Multiple modalities excluded dissection; however, an intraluminal filling defect supported thrombus in the right proximal internal carotid artery (ICA). Subsequent ultrasound imaging demonstrated a mobile thrombus at the origin of the ICA arising from the posterior wall. Intraoperative notes suggested the presence of a carotid web associated with thrombus formation, and subsequent histopathology confirmed this finding.

Carotid webs represent focal septum-like luminal protrusions, usually at the level of the ICA ostium. Strokes associated with carotid webs are considered rare, with an incidence of 0.7%-2.5%. However, the stroke re-occurrence rate in this population is 44% on best medical therapy. This case demonstrates the potential difficulty of discerning a web in the presence of thrombus on CTA, MRI and ultrasound. Furthermore, it highlights the high-risk properties of carotid webs for thrombus formation and as a potential cause of stroke. Carotid webs should be excluded as a potential cause of stroke, particularly in young and African populations where the incidence of carotid webs is suspected to be higher. Sonographer education specific to carotid webs is needed for accurate and timely detection of this rare disease.