Key Points
Î Voice disturbance may be identified at least temporarily in up to 80% of
patients after thyroid surgery.
Î About 1 in 10 patients experience temporary laryngeal nerve injury after
surgery, with longer lasting voice problems in ≤1 in 25.
Î The most common site of neural injury is the distal recurrent laryngeal nerve
(RLN), which can be nonrecurrent in 0.5%-0.7% of cases (See figures below).
• The other nerves of major interest, and frequently less directly addressed during thyroid
surgery, are the bilateral superior laryngeal nerves (SLN), injury to which can impair the
ability to change pitch and reduce voice projection.
• Another less common surgical cause for post-thyroidectomy voice change may be cervical
strap muscle injury.
• Nonsurgical causes may include laryngeal irritation, edema, or injury from airway
management.
Figure 4: Variations of Non-Recurrent Recurrent Laryngeal Nerve
From Stewart, Mountain, and Colcock. (1972) Non recurrent laryngeal nerve, Brit. J. Surg. 59:379-381
Course and branches of RLN and SLN
From Randolph GW, ed. Surgery of the yroid and Parathyroid Glands. 2nd ed. Philadelphia, PA: Elsevier
Saunders; 2013. Reprinted with permission.
From Stewart GR, Mountain JC, Colcock BP. Non-recurrent laryngeal nerve. Br J Surg. 1972;59(5):379-381.
Relationship of RLN and SLN to thyroid
lobe and tracheoesphageal groove
Variations of nonrecurrent recurrent laryngeal nerve
