Superior laryngeal nerve injury

Introduction to laryngeal nerve injury The laryngeal nerve is derived from the vagus nerve. The node is located close to the jugular foramen and is divided into inner and outer branches on the plane of the hyoid bone. The outer branch is often accompanied by the superior thyroid artery on the way down, usually in front of the superior thyroid artery. Secondly, the superior laryngeal nerve is located on the lower side of the inferior pharyngeal muscle. Later, it is located under the sternohyoid muscle and thyroid cartilage, and the vulvar muscle is also accepted. Therefore, the outer branch is covered by the fascia of the inferior phlegm muscle before entering the ring muscle. basic knowledge Sickness ratio: 0.05% Susceptible people: no specific population Mode of infection: non-infectious complication:

Cause of laryngeal nerve injury

1. Neck trauma (knife wounds, gunshot wounds, etc.).

2. Secondary to thyroid surgery, the superior thyroid artery is closely associated with the nerve, so when the upper thyroid artery is ligated, the nerves can be ligated together.

3. Upper laryngectomy, easy to damage the superior laryngeal nerve.

Prevention of laryngeal nerve injury

1. Avoid large bundle ligation of the thyroid gland

Ligation of the thyroid gland in time, should be as close as possible to the gland, avoid large bundle ligation, a large part of the resection of a leaf, easy to stop bleeding after resection, for easy bleeding, rather for total leaf resection, the subtotal for hyperthyroidism should be done, it is best not to Most of the bilateral symmetry is removed, and one leaf is completely cut, and the other side is mostly or half cut.

2. The inferior thyroid artery is an important marker of exposed nerves

First, the anatomy is started from the lower part of the artery, and the nerve is inserted into the throat, and then the glandular tissue at the outer part of the annular cartilage is separated. The position where the nerve enters the throat is the most vulnerable part, and it is also the most prone to bleeding. Special attention must be paid when stopping bleeding.

3. Avoid bilateral laryngeal nerve injury

In order to avoid bilateral laryngeal nerve injury, when the bilateral thyroid is removed, the laryngeal nerve is exposed on one side, and one side of the thyroid is removed. The laryngoscope and electrostimulator are used to observe the movement of the vocal cord. If there is no movement on the side of the vocal cord, The contralateral thyroid cannot be removed.

Superior laryngeal nerve injury Complication

Neck nerve damage often occurs simultaneously with vascular injuries.

Symptoms of laryngeal nerve injury Common symptoms Difficulty breathing Difficulty swallowing speech frequency is small, no... The sound becomes lower and the ring muscle loses contraction...

1. Unilateral laryngeal nerve injury After the laryngeal nerve is separated from the vagus nerve, the stroke in the neck is shorter, the damage is less than the recurrent laryngeal nerve, and it is generally unilateral, easily injured and its external branches.

(1) Symptoms: The frequency range of speech is reduced, and high-pitched sounds cannot be made.

(2) Physical examination: the edge of the affected vocal cord is not neat and arched. The thyroid cartilage is twisted to the healthy side due to the contraction of the healthy side of the ring muscle, and the healthy side of the annular cartilage is lifted up.

Guttman test: When a normal person presses the thyroid cartilage from the front, the sound becomes low; if it is pressed from the side, the sound becomes high, and when the tendon tendon is rubbed, the above side has the above signs.

2. bilateral laryngeal nerve injury

(1) Symptoms: High notes cannot be made and the sound is monotonous.

(2) Physical examination: The vocal cords have wrinkles due to the action of the nail muscles, and the fingers are placed on the ring membrane to palpate. When the sound is heard, the affected side of the ring muscles loses contraction or traction. When the unilateral or bilateral superior laryngeal nerve is damaged, it does not cause difficulty in breathing and difficulty in swallowing.

Examination of laryngeal nerve injury

Laryngoscopy, unilateral injury showed that the glottis was oblique, the vocal cord on the affected side was lower than the healthy side; the longitudinal tension of the bilateral vocal cords disappeared and wrinkles appeared. patients do swallowing, if there is damage to the supraorbital nerve can cause cough. patients do vocal movements, if accompanied by laryngeal nerve damage can cause hoarseness and dysphonia. Comprehensive judgment can be made based on laryngoscopy and clinical symptoms.

Diagnosis and differentiation of laryngeal nerve injury

The superior laryngeal nerve injury is mainly distinguished from the recurrent laryngeal nerve injury, both of which are common complications after thyroid surgery. Recurrent laryngeal nerve injury mainly leads to a change in tone. If both recurrent laryngeal nerves are damaged, suffocation and inability to pronounce may occur. If it is found that immediate bedside rescue is required, tracheal intubation resuscitation sac assisted breathing may be performed, and mechanical ventilation may be performed if necessary.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.