During right thyroid lobectomy, a nerve is found taking a direct transverse course across the lower neck instead of ascending in the tracheoesophageal groove. The surgeon should suspect:

• A A double aortic arch with vascular ring
• B An aberrant right subclavian artery arising directly from the aortic arch ✓
• C Persistent left superior vena cava
• D Retrosternal extension of the goitre displacing the nerve medially

Explanation

B non-recurrent right laryngeal nerve arises directly from the vagus and crosses the neck horizontally to enter the larynx. Its anatomical prerequisite is an aberrant right subclavian artery arising from the descending aorta and passing behind the oesophagus, so the nerve never loops around the vessel. It occurs in about 0.5 to 1 percent of individuals and is a recognised cause of inadvertent nerve division, since the surgeon expects the nerve in the tracheoesophageal groove. It is almost exclusively a right-sided anomaly.

Reference: Schwartz's Principles of Surgery, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.