Abstract
- The trachea is 10–12 cm long and 2–2.5 cm wide, extending from C6 to T5.
- The trachea is composed of 16–20 incomplete rings with a flattened posterior wall of muscle and fibrous tissue.
- The anatomic borders of the trachea include the isthmus of the thyroid and paired strap muscles anteriorly. The common carotid arteries, thyroid lobes, and recurrent laryngeal nerves form the lateral borders.
- The paired strap muscles are in front of the trachea and larynx. These include the sternohyoid muscles and the underlying sternothyroid and thyrohyoid muscles.
- The thyroid cartilage is suspended from the hyoid bone by the thyrohyoid membrane. The cricothyroid ligament connects the inferior portion of the thyroid cartilage to the cricoid cartilage. Inferior to this is the first tracheal ring.
- The larynx is composed of three paired (arytenoid, corniculate, and cuneiform), and three unpaired (cricoid, thyroid, and epiglottic) cartilages.
Surgical Anatomy
The trachea is 10–12 cm long and 2–2.5 cm wide, extending from C6 to T5.
The trachea is composed of 16–20 incomplete rings with a flattened posterior wall of muscle and fibrous tissue.
The anatomic borders of the trachea include the isthmus of the thyroid and paired strap muscles anteriorly. The common carotid arteries, thyroid lobes, and recurrent laryngeal nerves form the lateral borders.
The paired strap muscles are in front of the trachea and larynx. These include the sternohyoid muscles and the underlying sternothyroid and thyrohyoid muscles.
The thyroid cartilage is suspended from the hyoid bone by the thyrohyoid membrane. The cricothyroid ligament connects the inferior portion of the thyroid cartilage to the cricoid cartilage. Inferior to this is the first tracheal ring.
The larynx is composed of three paired (arytenoid, corniculate, and cuneiform), and three unpaired (cricoid, thyroid, and epiglottic) cartilages.
General Principles
Stridor, respiratory distress, blowing neck wound, hemoptysis, and subcutaneous emphysema are all signs and symptoms of a tracheolaryngeal injury.
Direct laryngoscopy is used to evaluate for suspected laryngeal injury; bronchoscopy is used to identify tracheal injury.
In the presence of tracheal trauma, there is a high incidence of associated injury, including vascular and digestive tract injury.
In suspected airway injury, obtaining a definitive airway should be of highest priority. This is often best achieved in the operating room.
Instruments
A standard instrument tray can be used for tracheal and laryngeal dissection. Weitlaner or cerebellar retractors and a tracheal hook are recommended for exposure, especially in the deep neck.
A size 6 and 8 tracheostomy tube should be available in the event of a large tracheal injury or lost airway.
Patient Positioning
In a patient with isolated neck and no cervical spine injury, it is ideal to place a bump or shoulder roll underneath the upper back and allow the patient’s head to extend, thus opening up the neck for improved exposure. This position elevates the trachea and allows for more distal access, above the sternal notch.
If there is concern for cervical spine injury, the patient must be kept in spinal precautions and no shoulder roll should be used. Cervical spine stabilization can be accomplished using bilateral sandbags.
Incisions
The choice of incision depends on the mechanism of injury (blunt or penetrating), the location of the injury, and the suspected presence of associated injuries (i.e. esophagus or major vessel).
For tracheal injuries, a collar incision is made approximately 2 fingerbreadths above the sternal notch, extending to the medial borders of the sternocleidomastoid muscles.
After the collar skin incision is made, the platysma is divided, and subplatysmal flaps are created superiorly and inferiorly to expose the strap muscles.
The strap muscles are divided in the avascular plane along the midline to expose the trachea, larynx, and thyroid gland.
