Characteristic travelling patterns of non-recurrent laryngeal nerves

The non-recurrent laryngeal nerve is subject to potential injury during thyroid surgery. Intra-operative identification and preservation of this nerve can be challenging. Its presence is associated with an aberrant subclavian artery and the developmental absence of the brachiocephalic trunk. This study aimed to evaluate the incidence of non-recurrent laryngeal nerves and present a new classification system for the course of these nerves.

Non-recurrent laryngeal nerves were identified on the right side in 15 patients who underwent thyroidectomy. The incidence of non-recurrent laryngeal nerves (during thyroidectomy) and aberrant subclavian arteries (using neck computed tomography) was evaluated, and the course of the nerves was classified according to their travelling patterns.

The overall incidence of non-recurrent laryngeal nerves was 0.68 per cent. The travelling patterns of the nerves could be classified as: descending (33 per cent), vertical (27 per cent), ascending (20 per cent) or V-shaped (20 per cent).

Clinicians need to be aware of these variations to avoid non-recurrent laryngeal nerve damage. A retroesophageal subclavian artery (on neck computed tomography) virtually assures a non-recurrent laryngeal nerve. This information is important for preventing vocal fold paralysis. Following a review of non-recurrent laryngeal nerve travelling patterns, a new classification was devised.