Imaging of Aberrant Internal Carotid Arteries

Aberrant internal carotid arteries (ICAs) may take abnormal courses in the cervical region. We present the ICA imaging features that suggest the presence of a submucosal mass in the posterior pharyngeal wall caused by such an aberration.

Cervical computed tomography angiography images of 2400 patients obtained over 5 years were retrospectively reviewed. The ICA courses at the levels of the hypopharynx and oropharynx were evaluated. Aberrant ICAs running posterior to the pharynx were selected. Vessel location was classified into 3 types: lateral to the vertebral foramen (normal, type I); between the lateral foramen and the uncovertebral joint (type II); and medial to the uncovertebral joint (type III). Medical records were examined, and relationships between symptoms, the ICA variations, and imaging features evaluated.

Cervically aberrant ICAs of type II were detected in 45 patients and aberrations of type III in 18. In the latter group, the mean patient age was 66 years, 12 were men and 6 were women. Six (33%) patients (4 men) had clinical symptoms associated with their aberrant ICA courses. In 2 men (11%), both ICAs took aberrant courses. Otherwise, the right ICA was affected in 9 (50%) cases and the left ICA in 7 (39%).

Parapharyngeal ICA aberrations were both common and asymptomatic. Such ICAs may be damaged during pharyngeal surgery or intubation. The ICA location should be investigated before any interventional procedure.