Laryngeal trauma

Laryngeal trauma is uncommon in the setting of external blunt or penetrating trauma. The larynx may also be injured internally, for example during endotracheal intubation.

Clinical presentation

Symptoms include hoarseness, laryngeal pain, dyspnea, and/or dysphagia. Also, stridor, hemoptysis, subcutaneous emphysema and tenderness/deformity of the larynx skeleton may be present. Laryngeal trauma in a significant number of patients may be clinically occult ⁶.

Pathology

Etiology

The larynx may be injured in a number of ways ^1,2,6:

• external blunt: motor vehicle accidents, "clothesline" accidents, strangulation, falls, sporting injuries
• external penetrating: stabbing, shooting
• internal blunt: iatrogenic during endotracheal intubation or fibroendoscopic examination

Location

The following laryngeal structures may be injured in isolation or combination ^1,2:

• laryngeal edema, hematoma and/or mucosal lacerations
• thyroid and/or cricoid cartilage fracture
• laryngeal rupture
• cricotracheal separation
• cervical tracheal injury

The hyoid bone, although technically not part of the larynx, can also be fractured.

Associations

Other injuries are common ¹:

• base of skull or facial fractures (~20%)
• cervical spine fractures (~10%)
• thoracic and abdominal injuries

Radiographic features

CT is the modality of choice. Review of airway obstruction includes evaluation of edema, hematoma, foreign body or displaced fractures.

CT review for larynx function should also include close inspection for lacerations especially to the vocal cord and anterior commissure, and arytenoid cartilage dislocation or avulsion.

Treatment and prognosis

The key goals of management are:

• maintaining airway: preserve life
• restoring function to larynx: voice quality

Blunt trauma has a worse prognosis than penetrating trauma with increased length of stay and short-term mortality (40% vs 20%) respectively ⁶. 

Complications

Complications include ⁶:

• airway stenosis
• respiratory tract infection
• aspiration
• tracheo-esophageal fistula

Practical points

1. Uncooperative or unstable patients may not be in the normal anatomical position on the CT scanner. Often useful to use a 3D workstation to facilitate proper review of soft tissue injuries to the true cords versus the false cords, and position of the cricoid cartilages. 
2. CT is superior to laryngoscopy and clinical exam for:
   • detection of cartilage fractures
   • evaluation of the subglottic and anterior commissure regions which are poorly visualized on endoscopy
3. Do not forget to assess for associated cervical spine and vascular injuries.
4. A key indirect sign of laryngeal injury is subcutaneous emphysema. If this is present look for subtle laryngeal and tracheal injury. There can be a ball-valve derangement that forces massive amounts of air into the neck and chest leading to tracheal displacement and pneumothorax. Thus, patients with laryngeal trauma should not have excessive mask ventilation.
5. Look for tracheolaryngeal separation: should not have intubation, but require tracheostomy.