The Recurrent Laryngeal Nerve does not lie in the Tracheo-esophageal Groove

Traditional anatomic textbooks suggest that the recurrent laryngeal nerve (RLN) ascends in the tracheoesophageal groove (TEG). However, during thyroid and parathyroid surgery, we have noted that the RLN is often not in the groove. In this study, we objectively measured the course of 41 RLNs in relation to the TEG. We found that the RLN was in the groove in only one case. On the right, the angle ranged from 0 – 50°(mean 27.5°) and on the left the range was 15 – 45°, (mean 25.5°) away from the TEG. In conclusion, it was unusual for the RLN to lie in the tracheo-esophageal groove. Thus, in mobilizing the thyroid lobe medially during thyroidectomy, one must exercise care as it is likely that one will encounter the RLN well lateral to the groove. We propose a new technique of objectively measuring the deviation of the RLN from the TEG.