A unique variation with five branches of the aortic arch

Area of Science:

• Anatomy
• Vascular Biology
• Surgical Anatomy

Background:

• The aortic arch (AA) typically exhibits a standard branching pattern, with variations occurring infrequently.
• Understanding these variations is crucial for accurate diagnosis and surgical planning in cardiovascular and neck procedures.

Observation:

• A unique case of a five-branched aortic arch (AA) was identified.
• The branching pattern included the right common carotid artery, left common carotid artery, left thyrocervical trunk, left subclavian artery, and right subclavian artery (RSA).

Findings:

• The left thyrocervical trunk originated directly from the AA, deviating from the usual origin from the left subclavian artery.
• The RSA arose dorsally as the final branch of the AA, passing posterior to the esophagus to supply the right upper limb.
• The right vertebral artery originated from the right common carotid artery, not the RSA.

Implications:

• This case represents the first documented instance of a left thyrocervical trunk directly arising from the AA and a dorsal RSA as the last branch of a five-branch AA.
• The findings provide critical anatomical information for radiologists, anatomists, and surgeons operating on the neck and thorax.
• Awareness of such rare AA variations can prevent misdiagnosis and improve surgical outcomes.