Carotid Bulb Webs as a Cause of "Cryptogenic" Ischemic Stroke

Abstract

Background and purpose: Carotid webs are intraluminal shelf-like filling defects at the carotid bulb with recently recognized implications in patients with recurrent ischemic stroke. We sought to determine whether carotid webs are an under-recognized cause of "cryptogenic" ischemic stroke and to estimate their prevalence in the general population.

Materials and methods: A retrospective review of neck CTA studies in young patients with cryptogenic stroke over the past 6 years (n = 33) was performed to determine the prevalence of carotid webs compared with a control group of patients who received neck CTA studies for reasons other than ischemic stroke (n = 63).

Results: The prevalence of carotid webs in the cryptogenic stroke population was 21.2% (95% CI, 8.9%-38.9%). Patients with symptomatic carotid webs had a mean age of 38.9 years (range, 30-48 years) and were mostly African American (86%) and women (86%). In contrast, only 1.6% (95% CI, 0%-8.5%) of patients in the control group demonstrated a web. Our findings demonstrate a statistically significant association between carotid webs and ischemic stroke (OR = 16.7; 95% CI, 2.78-320.3; P = .01).

Conclusions: Carotid webs exhibit a strong association with ischemic stroke, and their presence should be suspected in patients lacking other risk factors, particularly African American women.

Fig 1.

Algorithm of inclusion criteria.

Fig 2.

A patient presenting with right-sided weakness demonstrating an acute, large left MCA territory infarct as seen on diffusion-weighted imaging (A), with coronal CTA MIP image (B) showing abrupt occlusion involving the M1 segment of the left MCA (yellow arrowhead). Sagittal and axial neck CTA images (C and D) reveal a shelf-like intraluminal protrusion arising from the posterior wall of the left carotid bulb (red arrows), compatible with a carotid web.

Fig 3.

Low-magnification photomicrograph (A) shows extensive fibromuscular proliferation (scale bar = 500 μ). High magnification (B) shows proliferating smooth muscle cells (arrow) and myxoid degeneration (asterisk).