Chapter 34. Laryngeal Trauma

• Hoarseness, neck pain, crepitus, loss of normal midline neck landmarks.
• Fiberoptic examination is a key to the diagnosis; computed tomography scans are extremely helpful.
• Consider concomitant injuries with penetrating trauma.

The larynx serves three important functions: airway protection, regulation of respiration, and phonation. Injury to the larynx resulting from trauma can therefore be devastating. Fortunately, laryngeal trauma is rare and occurs in only a small percentage of trauma victims. Standardized protocols have been developed to help guide the accurate evaluation and identification of injuries requiring operative intervention. Early diagnosis and treatment are critical to prevent dire consequences, including death.

External Laryngeal Trauma

The relatively low incidence of laryngotracheal injuries results from the natural defenses that the body has to protect the vital structures that allow us to breathe. The relatively high position of the sternum and low position of the mandible along with the thick musculature of the lateral neck allow only a relatively short segment of the airway to be exposed.

Furthermore, there is a naturally protective reflex that causes the head to be flexed downward when startled, allowing for further protection of this region. Injury typically occurs when the body cannot protect this area. This generally occurs in motor or recreational vehicle accidents, assaults (including domestic violence), sports injuries, or strangulation. In motor vehicle accidents, the laryngeal skeleton and/or cricoid cartilage may be shattered between the steering wheel and the cervical spine. Clothesline injuries, although rare, may result classically in cricotracheal separation and bilateral recurrent laryngeal nerve injuries.

The pediatric age group deserves special mention because children have anatomic differences that make the management of laryngeal injuries a distinct entity when compared with the management of similar injuries in adults. Although children are less prone to laryngeal fracture owing to the high position of the larynx in the neck and the increased pliability of the laryngeal cartilage, their diminutive anatomy makes them more vulnerable to life-threatening complications from the injury.

Penetrating Neck Trauma

Penetrating trauma to the neck is challenging because up to 30% of patients have multiple structures injured. Penetrating neck trauma usually results from stabbings or gunshot wounds. The severity of a penetrating injury is determined by the mass and velocity of the missile. Therefore, generally, high-velocity, large-caliber bullets will create more damage. However, a variety of bullet types are available that can increase local tissue damage, either by breaking up or exploding on contact or by spiraling in the tissues.

Intubation Injury

Because of sophisticated intensive care units, critically ill patients are being sustained longer on ventilatory support with the potential long-term consequences of affected speech and airway patency. Such complications may include scarring of the laryngeal structures, subglottic or tracheal stenosis, formation of granulation tissue, and vocal fold paralysis/paresis. Although the true incidence is unknown, complication rates of 4–19% have been reported after prolonged intubation; therefore, converting an intubated patient to a tracheotomy is often contemplated after 5–7 days. The benefits of tracheotomy as a management strategy for the prolonged intubation patient include the ability to (1) decrease dead space, (2) improve pulmonary toilet, (3) increase comfort and decrease the need for sedation, (4) ease the process of weaning, and (5) lessen the risk of long-term complications.

Many factors determine the severity of intubation injury. Anatomic variations predispose some patients to a difficult or traumatic intubation. Underlying illness, infection, and reflux laryngitis all may exacerbate the injury. Although glottic edema and superficial ulceration may be seen within just hours of intubation, the use of large-diameter endotracheal tubes, excessive patient movement, repeated self-extubation, overinflated endotracheal tube cuffs, and prolonged intubation increase the risk of long-term damage.

Intubation-related injuries may be reduced by eliminating or controlling the above-listed factors. We routinely ensure that patients are maintained on antireflux medications while intubated. In addition, we attempt to ensure that cuff pressures are kept low. However, as we demonstrated in a recent paper, serial measurement of cuff pressures does not ensure proper pressure maintenance.

Arytenoid dislocation is a special consideration that has been reported as a result of intubation problems. The cause is likely either extreme force applied directly to the arytenoids by a laryngoscope or endotracheal tube or careless extubation with an inflated cuff. The diagnosis is controversial. Some clinicians propose that it is often misdiagnosed and may actually represent the appearance of new onset vocal fold paralysis.

Symptoms and Signs

Patient History

The evaluation of a patient with a suspected laryngeal injury begins with a detailed history (when possible) that specifically addresses the following items: (1) the development of symptoms, (2) the mechanism of injury, and (3) the trajectory of any involved weapons. This information is often difficult to elicit in a patient with multiple traumas because the ability to provide information is compromised by the severity of the injuries. These injuries can include communication deficits caused by concomitant head injuries or illicit substance abuse. Common symptoms include hoarseness, pain, dysphagia, odynophagia, and dyspnea. The failure to elicit these symptoms, however, does not ensure the integrity of the airway. Therefore, a high index of suspicion is mandatory in any patient with neck trauma.

Physical Examination

The physical examination begins with careful attention to the voice and breathing. The presence of hemoptysis, stridor, or crepitus should alert the physician to a high probability of airway injury. Point tenderness or flattening of the thyroid cartilage prominence is suggestive of an acute laryngeal fracture. Penetrating trauma may involve multiple vital structures such as the esophagus or the carotid neurovascular bundle. An expanding hematoma, a pulse deficit, or the presence of a bruit and thrill all are signs of vascular injury. The prompt diagnosis of these life-threatening injuries requires a methodical investigation. Further evaluation is directed by careful attention to subtle signs and symptoms (Figure 34–1).

One of the most important instruments in diagnosing laryngeal trauma is the fiberoptic nasopharyngoscope. In using this device, the larynx should be evaluated carefully for vocal cord mobility and arytenoid symmetry. Notation should also be made regarding findings of edema, hematoma, soft tissue tears, and exposed cartilage. An attempt should also be made to evaluate the upper trachea by direct examination if the patient tolerates the exam.

Imaging Studies

Conventional X-Rays and Soft Tissue Films

Plain-film x-rays of the chest and soft tissue neck films continue to be essential components in patient evaluation. Any abnormal air surrounding the trachea, mediastinum, or thorax may be the first sign of impending tension pneumothorax and airway embarrassment.

Computed Tomography (CT)

High-resolution fine-cut CT of the larynx is the best radiographic tool available to evaluate laryngeal trauma. It is especially helpful when the examination is normal but there is a high index of suspicion for occult laryngeal injury. A CT scan is not mandatory in patients with injuries that obviously require operative intervention or in asymptomatic patients with an unremarkable physical examination. However, CT scanning, especially with 3D reconstruction (Figure 34–2), may be valuable in helping to plan the operative procedure in a patient with a controlled and stable airway.

Rigid Esophagoscopy and Contrast Swallow Studies

Rigid esophagoscopy or contrast swallow studies are often used to rule out concomitant esophageal perforation in penetrating trauma. When used together, the sensitivity of these tests is approximately 90%. A water-soluble contrast may be preferred to barium because it is less inflammatory to soft tissues, especially if an injury is present or suspected. A negative study then may be repeated with barium, which provides more mucosal detail. A useful adjunct when not dealing with esophageal perforation is flexible esophagoscopy, either in the operating room or at the bedside using a transnasal esophagoscope. These instruments may offer more detail than is available with a barium swallow or rigid esophagoscopy.

Angiography

Angiography is often used in the diagnostic evaluation of penetrating neck trauma, especially when the injury involves Zones I and III. (See zone definitions in the section on Definitive Treatment.) Angiography is the gold standard for evaluating vascular injury and is therapeutic when used with interventional neuroradiology embolization. In some centers, duplex ultrasound or noninvasive angiography (CT or magnetic resonance angiography) has replaced conventional angiography for the evaluation of vascular injuries because of its lower cost and risk.

Emergent Management (for Unstable Patients)

The initial resuscitation begins with following three steps: (1) securing the airway, (2) obtaining hemodynamic stability while controlling the bleeding, and (3) immobilizing the cervical spine. The optimal choice of airway control is often debated. Intubation may be performed safely if the vocal folds are easily seen, there are no visible injuries, and the smallest tube possible is used. However, endotracheal intubation can cause further injury to an already tenuous airway, resulting in an emergent need for airway control. In addition, the extent of injury may not be known prior to attempted direct laryngoscopy. Surgical airway control such as an awake tracheotomy (performed under local anesthetic) or a cricothyroidotomy may often be more prudent in these situations. If a cricothyroidotomy is performed, it should be converted to a formal tracheotomy as soon as possible to prevent long-term sequelae (eg, subglottic stenosis).

In contrast to adults, pediatric patients are unlikely to cooperate with a tracheotomy while awake. In addition, their neck anatomy is often more challenging owing to a high laryngeal position and soft cartilage. Therefore, a pediatric airway is preferably secured with a rigid bronchoscope while maintaining spontaneous respiration before a tracheotomy is performed.

After stabilization of the airway, the patient should be examined and the injury stratified to help guide further management.

Definitive Treatment

External Laryngeal Trauma

Laryngeal injuries are grouped according to increasing severity (Table 34–1; Figure 34–3). Patients with Group I injuries have minor endolaryngeal hematomas or lacerations. These patients are treated successfully with medical management alone, typically. Group II injuries demonstrate airway compromise, more severe soft tissue injury, or single nondisplaced laryngeal fractures. These patients are usually managed with a tracheotomy followed by direct laryngoscopy and esophagoscopy. If an arytenoid dislocation is discovered, then closed reduction should be attempted. Group III injuries include patients with massive edema, mucosal tears with exposed cartilage, displaced fractures, or vocal cord immobility. Group IV describes the unstable larynx with comminuted fractures. A Group V classification is the most severe type of injury; these patients present with complete laryngotracheal separation. Injuries within Groups III–V require immediate operative repair and may involve the use of stent. The ability to restore the integrity of the larynx impacts a patient's long-term outcome with regard to voice, airway, and the quality of life. It must be noted that this classification system does not account for patients with significant injuries (displaced fractures with altered vocal quality) who have mild or no airway compromise. These patients will often present later with complaints of hoarseness alone. If the injury was relatively recent, repair may be attempted to improve long-term functional outcome.

Nonsurgical Measures

Group I and II injuries often heal spontaneously and have excellent outcomes. These injuries are usually managed nonsurgically with humidified air, head of bed elevation, and voice rest. To prevent complications from an undetected or progressive injury, the patient should be closely observed with serial fiberoptic examinations and continuous pulse oximetry for 24–48 h. Antibiotics are often prescribed when there is observable mucosal injury. The use of steroids is controversial. Steroids probably decrease edema if given within the first few hours after injury. The prophylactic treatment of laryngopharyngeal reflux is also recommended to prevent exposure of an injured larynx to acidic gastric contents.

Surgical Measures

In more severe injuries, the careful approximation of mucosal tears and the reduction of fracture segments are required to prevent long-term voice disturbance or airway compromise. Findings that tend to lead to a recommendation for surgery include: (1) lacerations involving the anterior commissure, injury to the free edge of the true vocal fold, or the finding of exposed cartilage; (2) displaced or comminuted fractures; (3) vocal fold immobility; or (4) arytenoid dislocation.

Some data indicate that patients with treatment delays of 48 hours have inferior outcomes when compared with patients whose injuries are repaired soon after the initial trauma. Early intervention is generally preferable since it allows an accurate identification of the injury, less scarring, and superior long-term results.

Fractures can affect the voice by changing the geometry of the larynx and glottal configuration. Therefore, the precise reduction and fixation of even minimally displaced or angulated fractures is often advocated. Fractures traditionally have been repaired with stainless-steel wires or absorbable sutures. Miniplates (titanium or absorbable) provide immediate stability and good results (Figure 34–4) although they are often difficult to place in the cartilaginous framework.

When there is significant disruption of the endolaryngeal soft tissue, a midline thyrotomy to the level of the cricothyroid membrane is performed through a horizontal anterior neck incision. The arytenoids are palpated and reduced if dislocated or avulsed. Only obvious devitalized tissue is débrided. Mucosal lacerations are repaired with primary closure or local flaps to cover any exposed cartilage with the goal of preventing perichondritis, the formation of granulation tissue, and scarring. Grafts are rarely needed.

The use of stents is controversial because of the increased risk of infection and granulation formation. Stents provide structural stability and are indicated in patients with laryngeal instability following inadequate fracture fixation. In the presence of severe soft tissue disruption or lacerations involving the anterior commissure, stents may help prevent synechiae. After 1 or 2 weeks, they are typically removed endoscopically.

Penetrating Neck Trauma

Penetrating neck trauma is classified by the level of injury based on the clinical features and the ease of surgical access: (1) Zone I extends from the sternal notch to the cricoid; (2) Zone II extends from the cricoid to the angle of the mandible; and (3) Zone III extends cranially from the mandible to the skull base. This classification system directs the diagnostic evaluation and treatment.

With sophisticated ancillary tests and the accurate identification of localizing signs and symptoms, the surgical exploration of penetrating neck trauma is being used increasingly on a selective basis. Immediate operative exploration including triple endoscopy (direct laryngoscopy, bronchoscopy, and esophagoscopy) is used for all patients with hemodynamic instability or airway compromise. The hypopharynx should be closely inspected for injury. Injuries above the level of the arytenoids often heal spontaneously and may be expectantly managed. Lower hypopharyngeal and cervical esophageal injuries require open exploration, primary closure, and drainage due to the higher incidence of salivary leak, infection, and subsequent fistula.

The stable patient is stratified depending on the presence of other signs or symptoms such as expanding hematoma, dysphonia, hemoptysis, hematemesis, or dysphagia. This group of symptoms is explored more selectively.

Injuries crossing into Zones I and III of the neck are more difficult to examine clinically and approach surgically; therefore, imaging—including angiography—is often performed. Zone I injuries are studied with preoperative arteriography and often gastrograffin swallow studies because of the risk of occult injuries reported by some clinicians. Because of difficult surgical access to the vasculature at the base of the skull, patients with Zone III injuries are also studied with arteriography, with the therapeutic option of embolization should an injury be found. Patients with isolated Zone II injuries, however, are usually explored surgically, often without imaging.

The management of asymptomatic patients is controversial. With these patients, some evidence supports observation alone because the physical examination is extremely sensitive in detecting injuries that require operative intervention. In these patients, imaging and adjunctive testing are very helpful in guiding further management.

Intubation Injury

Intubation injuries may cause a wide variety of acute and chronic conditions. High endotracheal tube cuff pressures may cause progressive hoarseness or airway obstruction from glottic or subglottic edema. Compressive neuropathies caused by direct pressure of the cuff may lead to vocal fold paralysis. Mucosal injury is commonly seen, particularly in the posterior larynx and subglottis and usually results from pressure necrosis due to the presence of the tube and/or cuff or from traumatic intubation. These injuries may progress and lead to granuloma formation, fixation of the cricoarytenoid joint, web formation, or stenosis. The incidence of posterior glottic stenosis increases with the length of intubation and may occur in up to 14% of patients intubated for more than 10 days. Differentiating glottic stenosis from vocal fold paralysis can often be difficult, since both result in partial or complete vocal fold immobility. Typically, the cause of the immobility can be elucidated either by manual assessment of arytenoid mobility or by the use of laryngeal electromyography.

Most cases of granulation tissue formation seen after intubation trauma resolve spontaneously after some time. However, further treatment may be necessary in certain cases. This treatment typically involves a combination of voice therapy and antireflux medication. This combination reduces the impact of behavioral and local inflammatory factors that are presumed to cause ongoing laryngeal irritation. In certain refractory cases, botulinum toxin injections can be used to forcibly reduce the impact of ongoing phonotrauma. Pulsed-dye or pulsed potassium titanyl phosphate laser treatment has also been successful. Operative removal of the granuloma is rarely necessary except in cases of partial airway obstruction. It should be noted that surgical removal does not obviate the need for voice therapy and antireflux medications. Without controlling these factors, granulomas may recur after surgical excision alone.

The management of stenosis depends on its location and severity. It may be detected weeks or months after extubation, when a patient presents for the evaluation of recent exercise intolerance or stridor. Thin webs that tether the anterior glottis can be surgically divided. A keel may then be placed to prevent the web from reforming between apposed denuded mucosa. Posterior laryngeal stenosis and cricoarytenoid joint fixation are typically treated with repeated dilation through an endoscopic approach. However, occasionally, an open approach through a laryngofissure or the use of a stent is required. Other techniques utilized to treat failures or more severe cases include arytenoidectomy or partial posterior cordotomy.

Subglottic or tracheal stenoses may be initially approached with endoscopic laser incision and dilation. More severe stenoses may require laryngotracheal reconstruction or segmental resection with primary anastomosis. Tracheal segments 4–5 cm in length may be removed if performed with release maneuvers.

In unilateral vocal fold paralysis, patients with persistent dysphonia or significant aspiration—despite therapy—may benefit from vocal fold augmentation with a temporary injection material while awaiting the spontaneous return of function. A medialization laryngoplasty with or without arytenoid adduction or injection augmentation with a more permanent substance is typically recommended if the paralysis is likely to be permanent.

Patients with bilateral vocal fold immobility often present with stridor. Relieving the airway obstruction may require a partial posterior cordectomy, arytenoidectomy, or arytenoid lateralization procedure. In more pressing cases, airway relief is often provided via a tracheostomy.

The finding of arytenoid dislocation is suggested by an uneven vocal cord level seen on laryngoscopy. However, this appearance can also be seen with vocal fold paralysis, which occurs much more commonly. Laryngeal EMG and CT scanning can be used to clarify the diagnosis.

The initial goal in managing laryngeal trauma is to preserve life; the secondary goal is to prevent long-term sequelae to the voice and airway. Although the injuries to the larynx and trachea can be life altering, it has to be remembered that early aggressive intervention may also lead to long-term complications. In many instances of more minor injury, the best course is conservative observation, particularly with asymptomatic airway stenosis. Complications of more aggressive treatments, such as laryngofissure, laryngotracheal reconstruction, and tracheal resection may include worsening voice, restenosis, airway loss, pneumothorax, infection, vocal fold paralysis, and fistula formation.

Seatbelts, traffic safety devices, speed limits, technologic advances in automotive safety (eg, airbags), and neck protective devices used in sports continue to be the mainstay of accident prevention. These safety measures have resulted in a decrease in the incidence of blunt trauma. The adherence to careful intubation techniques, the early identification of patients who require tracheotomy for prolonged intubation, and the development of softer and relatively inert endotracheal tubes have also contributed to a decrease in the incidence of iatrogenic intubation-related injuries.

Postintubation injury occurs more frequently than is brought to clinical attention. Most injuries heal spontaneously and never require further intervention. As more factors that may contribute to these injuries are elucidated, the severity and incidence of complications may be minimized.

Penetrating neck trauma is associated with a 3–6% fatality rate. Management strategies evolve toward the selective exploration of these injuries.

The outcomes of laryngeal trauma in patients managed according to the protocols discussed earlier have been consistently satisfactory. Group I or II injuries heal almost uniformly with excellent results. However, some select injuries (eg, displaced cricoid cartilage, arytenoid subluxation, or recurrent laryngeal nerve injury) carry a more unfavorable prognosis. Study findings indicate that suboptimal results are only seen in patients with more severe injuries.

We would like to acknowledge Dov C. Bloch for his contribution to this chapter in the previous editions of CDT.