The recurrent laryngeal nerve is a branch of the vagus nerve which on the right side arises in front of the subclavian artery and on the left side to the left of the arch of the aorta. On each side the nerve ascends in the groove between the trachea and the esophagus and enters the larynx, branches going to all the muscles except the cricothyreoideus. An injury to both recurrent nerves in the course of a thyroid operation is a calamity.
The prevailing attitude of surgeons toward the recurrent nerves, which is partly erroneous, has been unchanged from the beginning of thyroid surgery. Kocher's position in advocating that partial thyroidectomy be done under local anesthesia so that, in having the patient speak, the surgeon might learn that the recurrent nerves were not injured, was unsound. There are temporary changes in the voice in some patients immediately after and probably during