Head and Neck Imagingarteria lusoria
aberrant right subclavian
artery leaving the
aorta below the left subclavian
artery, crossing the midline behind the
oesophagus; in very rare cases, this aberrant
artery may run between the trachea and
oesophagus (
Fig. 1). The reported incidence of this anatomical variant varies between 0.4 and 3%. Sometimes, this anomaly may cause dysphagia (see
vascular impression, oesophageal
), but most persons with this aberrant
artery have no related symptoms.
Normally, the right laryngeal recurrent nerve passes below the right subclavian
artery. As the normal right subclavian
artery is absent, the right inferior laryngeal nerve will move further cranially during elongation of the neck, passing more or less directly from the vagal nerve to the larynx. This is of importance in neck surgery, particularly in
thyroid and
parathyroid surgery, as non-identification of this variant is associated with a higher risk of iatrogenic neural injury. Damage to the right recurrent nerve will cause permanent right vocal cord paralysis (see
distal vagal neuropathy
). Therefore, if a preoperative imaging study, such as
CT or
MRI, is performed in these patients, identification of an arteria lusoria and reporting its presence (and its association with a non-recurrent inferior laryngeal nerve) are important.
A left-sided arteria lusoria is extremely rare, only occurring in cases of
situs inversus
.
RH