Relative direction and position of recurrent laryngeal nerve for anatomical configuration

The present study aims to describe the course of the recurrent laryngeal nerve (RLN) using the tracheoesophageal groove (TEG) at the cricothyroid joint as a base line, and the configuration of RLN and inferior thyroid artery (ITA) for careful dissection in thyroid surgery. The RLN of left side is likely to be found posterior to ITA and course mainly from 0° up to 30° based on TEG near cricothyroid joint while the nerve of right side is likely to be found anterior to ITA in right side and course mainly from 15° up to 45° based on TEG. The contacting point of RLN with ITA locate from the tip of cricoid cartilage at about three tenth of the distance from the tip of cricoid cartilage to sternal notch without reference to individual body size. 70 cadavers were investigated. The angle of RLN from TEG was measured at the cricothyroid joint. The relative position of RLN to ITA was classified. The location of the contacting point of RLN with ITA was measured and converted as an index. These findings suggest the area for careful dissection near cricothyroid joint, the configuration of RLN for identifying the nerve.