Recurrent Laryngeal nerve anatomy

RLN arises from the vagus nerve
- passes beneath vessel derived from the primitive 4th aortic arch
- on the right it recurs around the subclavian artery
- on the left it recurs around the aortic arch
- 1% of patients have a retroesophageal right subclavian artery and the laryngeal nerve arises directly from vagus to the larynx

Association with the inferior thyroid artery is variable.  Most course anterior to all branches, some course between branches and a few course totally behind branches of the inferior thyroid artery.
- text advocates encircling inferior thyroid artery as it arises from carotid and lifting it up to try and help identify the RLN.

Most consistent location of RLN is its insertion between the thyroid and cricoid cartilage.  Even in cases of recurrent laryngeal nerves it inserts in this location.  Its location relative to the cornu of the thyroid cartilage is quite consistent.
- This is where DCW looks for RLN initially.

External branch of the superior laryngeal nerve runs along the cricothyroid membrane and care should be taken to avoid damaging the SLN.

Silver and Rubin Atlas of Head and Neck Surgery: pg 284