Prospective Anatomical Study To Determine the Site of Insertion of Recurrent Laryngeal Nerve Into the Larynx

OBJECTIVES Determine whether the insertion site of the recurrent laryngeal nerve (RLN) occurs at a predictable distance from the midline trachea, to help guide safe dissection during thyroid surgery. DESIGN Prospective clinical trial. At the inferior edge of the cricoid cartilage, we measured the distance from mildline trachea to the RLN insertion site. SETTING Single institution. PARTICIPANTS 50 consecutive patients undergoing thyroid surgery. MAIN OUTCOME MEASURES Distance from midline trachea to laryngeal insertion of RLN. RESULTS The study population included 36 women and 14 men, with 72 total nerves measured. The average distance-to-midline + standard deviation (range) of the RLN was 20.7 + 2.3 (17-26) mm in women compared to 26.3 + 2.1 (22-32) mm in men. CONCLUSION The insertion point of the RLN into the larynx at the level of inferior border of the cricoid cartilage can be reliably predicted, to facilitate early identification of the RLN during thyroid surgery.