Recurrent laryngeal nerve (RLN) anatomy during thyroidectomy revisited

Abstract

Objectives: Previous anatomic studies of the RLNs have described the variability in the course of the recurrent laryngeal nerve. The anatomy of the nerve is more constant along its distal third portion near the cricothyroid joint, which is our surgical approach to the initial identification of the nerve. Some of the advantages of identifying the nerve more distally include less chance of disrupting the blood supply to the inferior parathyroid gland, dissection along a shorter portion of the nerve, and less variability. Understanding the topographical anatomy of the nerve in this region facilitates quick and safe nerve identification. The topographical anatomy of the nerve in this region has not been studied in detail, which is the focus of this study. Methods: A total of 150 RLNs were studied during thyroidectomy and the course of the nerve was recorded, paying particular attention to the directional course along its distal portion. The angle in which it coursed in relationship to a line paralleling the tracheoesophageal groove was determined. Results: We observed that 65% of the nerves coursed at 5–30 degrees, 22% coursed greater than 30 degrees, and 13% coursed less than 15 degrees. It appears that the nerve is more likely to travel at a more obtuse angle with right-sided RLNs and in patients with a low lying cricoid. The nerve rarly coursed over the inferior thyroid artery in this region. Conclusions: Approaching the nerve along its distal portion is safe and effective. The topographical anatomy in this region is described in detail.