The recurrent laryngeal nerve does not usually lie within the tracheo-oesophageal groove

Background: Traditionally, it has been taught that the recurrent laryngeal nerve (RLN) is anatomically located within the tracheo-oesophageal groove (TEG). However, a recent paper concluded that the RLN does not lie in the TEG. Notably, in this mentioned study, all data were taken intra-operatively in patients with pathological findings with a preponderance of thyromegaly or parathyroid disease. Aim: Accurate identification of the RLN is essential during surgical management of neck disease as nerve injury carries significant disability. We sought to examine the course of the RLN in necks devoid of pathology, to define the true anatomical course of the nerve. Materials and Methods: Neck dissections were performed on 26 cadavers, to expose a total of 52 RLNs. The angle of the RLN to the TEG was measured bilaterally in each neck. This was done by way of photography of each nerve in relation to the trachea, followed by digital measurement of the RLN: TEG angle (RTA). Any cases with neck pathology or previous surgery were excluded from this study. Results: In only 3 cases, all found on the left side, did the RLN run within the TEG. One non recurrent laryngeal nerve was found and in all other 48 cases, the RLNs coursed cranially and medially toward the TEG with a mean RTA of 27.9 and 21.5° on the right and left sides respectively. Conclusion: Our findings indicate that the RLN most often does not lie in the TEG but runs well lateral to it. Thus, during intraoperative neck dissection, in order to minimise RLN injury, the surgeon should expect to find the nerve well lateral to the TEG as it ascends to the cricothyroid joint.