What Is the Recurrent Laryngeal Nerve?

It originates from the thoracic segment of the vagus trunk, but immediately returns to the neck. It is the main motor nerve of the laryngeal muscle. Divided into left recurrent laryngeal nerve and right recurrent laryngeal nerve.

It originates from the thoracic segment of the vagus trunk, but immediately returns to the neck. It is the main motor nerve of the laryngeal muscle. Divided into left recurrent laryngeal nerve and right recurrent laryngeal nerve.

Chinese name

Recurrent laryngeal nerve

Definition

The main motor nerve of the larynx

Features

The left side is longer than the right side and the left side is vulnerable

Damage situation

Hoarseness caused by unilateral injury

Anatomy of the recurrent laryngeal nerve group

The right recurrent laryngeal nerve leaves the right vagus nerve in front of the first segment of the right subclavian artery, loops behind it, and then ascends into the trachea and esophagus groove. The left recurrent laryngeal nerve is located on the anterior and lateral side of the aortic arch, leaving the left vagus nerve close to the distal end of the arterial ligament, bypassing the aortic arch, and then ascending into the ipsilateral tracheoesophageal groove. After that, the recurrent laryngeal nerves traveled similarly until the level of the lower edge of the hypopharyngeal contractile muscle continued to the sublaryngeal nerve. The recurrent laryngeal nerve is a mixed nerve. Its muscles innervate the laryngeal muscles other than the ciliary thyroid muscle, and its sensory fibers are distributed to the laryngeal mucosa below the glottis.

The recurrent laryngeal nerve is longitudinally distributed, with a width of (1.85 ± 0.5) mm, white fibrous tissue, no tension, a small network of blood vessels on the surface, and nerve branches in a tree-like distribution.

Recurrent laryngeal nerve injury

Recurrent laryngeal nerve injury during thyroid surgery is a common clinical complication. Patients are mainly presented with hoarseness caused by unilateral recurrent laryngeal nerve injury, and poor breathing or even suffocation caused by bilateral recurrent laryngeal nerve injury. Especially with permanent nerve damage, once a nerve rupture occurs, it is often difficult to recover.

Recurrent laryngeal nerve injury is a common complication of neck surgery, which causes more injuries. We believe that insufficient understanding of the recurrent laryngeal nerve branch variation and its relationship with the inferior thyroid artery is the main cause of damage to the recurrent laryngeal nerve trunk or branch. The recurrent laryngeal nerve has many branches and has large variations. The recurrent laryngeal nerve usually appears in the right neck of the human body, such as:

(1) Sent from the vagus nerve, walk to the back of the lower angle of the thyroid cartilage and enter the throat.

(2) It is emitted from the hyoid bone of the cervical section of the vagus nerve, and walks from the outside to the inside to the throat under the lower angle of the thyroid cartilage.

(3) After branching from the vagus nerve trunk, it directly crosses the thyroid gland and enters the throat at the lower edge of the ring bone.

(4) The recurrent laryngeal nerve may be double or even three nerve trunks.

(5) Anastomoses are formed between the branches of the recurrent laryngeal nerve or between the branches and the cervical sympathetic nerve chain. The branch is issued at a high position and does not hook around the right subclavian artery. The vagus nerve branches directly into the throat, which is the so-called non-recurrent laryngeal nerve. Because the non-recurrent laryngeal nerve travels with the inferior thyroid artery when it enters the larynx, it is very easy to accidentally injure when ligating the inferior thyroid blood vessels. The recurrent laryngeal nerve can not only have variations in position and movement, but also its branches and traffic. If there is no understanding of this, it is easy to cause damage to the recurrent laryngeal nerve trunk or its important branches during surgery.

Variations of the recurrent laryngeal nerve are not only reflected in its location and branches, but also in the external shape of the recurrent laryngeal nerve itself, such as the recurrent laryngeal nerve crest, double recurrent laryngeal nerve, and non-recurrent laryngeal nerve. It is dendritic, and some recurrent laryngeal nerve branches and branches or branches and sympathetic nerve chains synthesize , and some recurrent laryngeal nerve branches emit planes above the lower thyroid plane, so two or three can appear on the thyroid plane. Nerve trunk; the recurrent laryngeal nerve exit site is high and does not hook up around the aortic arch or subclavian artery, and is branched out by the cervical vagus nerve directly into the throat. .