During thyroid surgery, the recurrent laryngeal nerve is at greatest risk at which specific anatomical location, and what vocal cord finding results from its complete bilateral division?
- A At the cricothyroid membrane; bilateral division causes bilateral cord paralysis in abducted position with no voice compromise but dysphagia
- B Near the upper pole of the thyroid; bilateral damage causes adducted cords with intact voice but swallowing difficulty
- C At the Beahrs' triangle near the inferior thyroid artery and tracheoesophageal groove; bilateral complete section causes bilateral vocal cords in median position with aphonia and severe dyspnea requiring emergency tracheotomy ✓
- D At the cricothyroid joint; bilateral section causes bilateral cords in paramedian position with intact voice and mild stridor
Correct answer: C. At the Beahrs' triangle near the inferior thyroid artery and tracheoesophageal groove; bilateral complete section causes bilateral vocal cords in median position with aphonia and severe dyspnea requiring emergency tracheotomy
Explanation
The RLN is most vulnerable where it enters the larynx near Berry's ligament (posterior suspensory ligament of the thyroid) at the Beahrs' triangle, where it crosses the inferior thyroid artery — in ~50%, the nerve passes posterior to the artery; in 25% anterior; in 25% between branches. Bilateral complete RLN division leaves both vocal cords in the median/paramedian position (Semon's law: abductors paralyzed first, then adductors), causing acute bilateral cord adduction with a silent voice and severe inspiratory stridor requiring emergency tracheotomy.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
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Written and medically reviewed by the StethoPrep medical team.