Penetrating Injuries of the Neck Treatment & Management

Patients with penetrating neck wounds without evidence of aerodigestive or vascular injury on clinical evaluation are admitted and observed for at least 24 hours. Ideally, these patients are monitored in the intensive care unit by nursing staff experienced in the care of patients with traumatic injuries, and repeat examinations are performed by a physician every 8 hours. Coverage with broad-spectrum antibiotics is standard, and treatment with H2 blockers is recommended.

Laryngotracheal injuries that do not require surgical repair are managed with serial examination, elevation of the head end of the bed, and corticosteroids. Esophageal tears are the most common injuries to be diagnosed late after a penetrating neck wound. Signs and symptoms suggestive of an occult esophageal injury include fever, tachycardia, chest pain, and widening of the mediastinum on chest radiographs. Mediastinitis is a potentially life-threatening complication of an undiagnosed esophageal injury that requires immediate attention and surgical intervention. Most vascular injuries present in the first 48 hours following injury with delayed bleeding, neurologic deficit, or hematoma development.

A study by Christian et al indicated that in properly selected patients, nonoperative management of penetrating injuries to the internal jugular vein carries a similar risk of morbidity and mortality as does operative management (although the rate of pneumothorax occurrences and ventilator days were higher in the study’s operative management patients). ^[19]

At the authors' institution, patients with penetrating neck injuries are treated according to a protocol of selective exploration. The decision to move a patient to the operating room is based on the initial presentation, physical examination findings, and results of the previously discussed imaging and diagnostic procedures. Patients with life-threatening injuries undergo immediate surgical exploration, followed by triple endoscopy (laryngoscopy, bronchoscopy, and esophagoscopy). Patients in stable condition undergo thorough investigation and then proceed to either surgical exploration and endoscopy or close observation.

The condition of all patients with penetrating neck injuries should be stabilized prior to any surgical procedure, emergent or elective. Stabilization includes the establishment of an airway, by means of intubation or tracheotomy, and resuscitation with intravenous fluids or blood products as needed. At minimum, preoperative radiologic studies should include anteroposterior and lateral plain radiographs of the neck. This allows evaluation of the cervical spine as well as estimation of the path and location of the missile in the neck. Further preoperative evaluation, as previously discussed, depends on the presentation and stability of the patient's condition. In the event of emergent exploration, blind clamping should not be exercised and hemostasis may require direct pressure or balloon tamponade until transfer to the operating room. ^[20]

Vascular injuries

The approach for vascular repair depends on the zone of injury. Zone 1 injuries are usually exposed via an oblique supraclavicular incision. Resection of the middle portion of the clavicle may be required for adequate visualization of the subclavian artery. Additionally, mediastinotomy extension or formal lateral thoracotomy may be necessary to control intrathoracic hemorrhage. Consultation with a thoracic surgeon is appropriate with zone 1 vascular injuries.

Vascular injuries in zone 2 are exposed through a standard neck dissection incision that follows the natural skin-tension lines in the middle portion of the neck. All veins in the neck may be ligated, although repair of one internal jugular vein should be considered if ligation of both veins is necessary. The external carotid artery and its branches may be safely ligated, if needed, for control of hemorrhage. Techniques for repair of the common and internal carotid arteries include lateral arteriorrhaphy, end-to-end anastomosis, and grafting. Ligation is considered only when attempts to repair the artery have failed. Shunt creation may be necessary to visualize and repair the carotid artery.

Zone 3 vascular injuries are difficult to access surgically and may require mandibular subluxation or mandibulotomy for exposure. The incision is similar to that used in zone 2, although it should be placed 2 cm below the mid mandible and 1 cm below the facial notch to avoid injury to the marginal branch of the facial nerve in a patient with a long neck. Vascular repair techniques are similar to those used in zone 2, but they are inherently more difficult because of the limited access. The digastric muscle may be split to provide access to the internal carotid. Angiography with embolization may be more successful in controlling arterial disruption at the skull base than surgical exploration and repair.

Laryngotracheal injuries

If a laryngotracheal injury is identified with physical examination or flexible laryngoscopy or if exploration is performed for another injury, direct laryngoscopy and bronchoscopy should be performed. Esophagoscopy should also be performed in patients with these injuries, because as many as 50% of patients with an airway injury also have a digestive tract injury. All laryngotracheal injuries may result in airway compromise; delayed compromise is possible. Physicians must be aware of the airway status at all times during the evaluation of patients with laryngotracheal injuries, and they must be prepared to secure the airway with tracheotomy if necessary.

The degree and type of injury must be carefully evaluated during endoscopic examination. Laryngeal injuries are classified by location (supraglottic, transglottic, cricoid, or tracheal) and type (hematoma, mucosal tears or lacerations, cartilage fractures and/or dislocations, or laryngotracheal disruption).

The surgical management of laryngeal trauma is based on the extent of injury during initial and endoscopic evaluation. Minor lacerations, small hematomas, and nondisplaced single fractures may be managed with observation and serial examination. Lacerations involving the anterior commissure or with exposed cartilage, multiple or displaced cartilage fractures, vocal cord immobility or arytenoid dislocation, or other injuries sufficient to cause airway compromise should be managed with exploration and repair. Occasionally, small lacerations and minor dislocations can be repaired endoscopically.

Timing of the repair of laryngotracheal injuries remains controversial. Some authors recommend waiting 3-5 days to allow swelling to subside, but better results have been obtained with earlier repair. Exploration of laryngeal injuries begins with an apron incision, and a midline thyrotomy allows entry into the larynx. Mucosal lacerations are repaired, and fractures are reduced and fixated with wire or permanent suture. Large tissue losses may be repaired with skin grafts or regional muscle flaps. The thyrotomy incision is closed, and drains are placed in the neck. Massive laryngeal injuries may require total laryngectomy in rare cases.

Tracheal injuries are usually approached via a lateral or transverse neck incision, with extension to a sternotomy or thoracotomy if needed. Small tracheal tears are closed primarily. More extensive tracheal injuries must be débrided to expose healthy mucosa. Sections of the trachea with deficits as large as 2-3 cm can usually be closed without excessive tension, but wider gaps may require extensive mobilization. Prophylactic tracheostomy is discouraged in patients with small tracheal wounds because of the increased risk of infection-related complications, but a tracheotomy almost always is required in more extensive injuries. Stent placement in laryngotracheal injuries after repair is controversial; it is usually recommended in anterior commissure injuries, comminuted fractures, and unstable fractures following reduction. Recurrent laryngeal nerve injuries should be repaired to help maintain muscle tone.

Pharyngeal or esophageal injuries

If a pharyngeal or esophageal injury is suspected on the basis of findings from clinical and radiologic evaluation or exploration for another injury, the upper digestive tract should be carefully evaluated. Some centers advocate a combination of flexible and rigid esophagoscopy to examine the entire cervical and upper thoracic esophagus.

Occasionally, pharyngeal injuries can be repaired transorally, but most esophageal injuries should be approached through a standard neck incision overlying the anterior border of the sternocleidomastoid muscle. Esophageal tears should be thoroughly irrigated, débrided, and closed in two layers. A muscle flap may be placed over the suture line to minimize fistula formation. Drains should be placed prior to closure of the neck. Extensive esophageal injuries may require lateral cervical esophagostomy followed by delayed closure.

Postoperatively, patients are monitored closely in the intensive care unit. Serial examinations are performed to identify any missed injuries. Use of broad-spectrum antibiotics and H2 blockers is standard for all patients with penetrating neck wounds. Anticoagulants may be indicated following repair of vascular injuries, if their use is not contraindicated by other injuries. Patients who undergo repair of laryngotracheal injuries receive antibiotics and H2 blockers or proton pump inhibitors for several weeks to reduce granulation tissue formation. After repair of esophageal injuries, patients are not given anything by mouth for 7-10 days; a nasogastric tube is placed for feeding.

Depending on the type and degree of injury, patients with penetrating neck trauma are likely to require frequent outpatient follow-up care. If an injury to a major organ system is never identified and if recovery is uncomplicated, long-term follow-up is not necessary. Significant vascular injuries can result in neurologic sequelae requiring short-term or long-term rehabilitation. Major carotid injuries and repairs should be evaluated postoperatively with Doppler ultrasonography; possible stenosis or aneurysm formation should be assessed.

Patients with laryngotracheal injuries require frequent examination with flexible and/or direct laryngoscopy to assess healing. If a tracheotomy is present, decannulation should be attempted as soon as possible, and stents placed during repair of laryngotracheal injuries should be removed in a timely manner. Repeat examinations are indicated to assess long-term vocal cord function and the development of stenosis. Esophageal injuries may result in stenosis, which requires endoscopic evaluation and possible dilation.

Early complications in patients with penetrating neck injuries include those related to the type and degree of injury. Bleeding may manifest at the time of presentation or may be delayed in patients treated with observation or surgical exploration. The management of acute hemorrhage and hematoma is discussed in previous sections. All patients with neck trauma are at risk for wound infections and sepsis because of the mechanism of injury and the potential communication with the aerodigestive tract. Mediastinitis is perhaps the most significant acute complication in these patients; it usually results from the delayed diagnosis of an esophageal injury. The mortality rates from esophageal injuries were found to increase from 11-17% after a delay in diagnosis of only 12 hours.

Long-term complications following vascular injuries may include neurologic deficits, carotid stenosis, or aneurysm formation. Laryngotracheal injuries may result in long-term tracheotomy dependence, subglottic stenosis, vocal cord paralysis and voice changes, and dysphagia. Esophageal injuries also may result in long-term dysphagia, usually secondary to stricture formation.

The current mortality rate for penetrating neck injury is 3-6%, with 50% of deaths caused by hemorrhage from vascular injuries. Vascular injuries cause complications in 40% of cases of penetrating neck injury, and 10% of patients have an injury to the carotid artery. Aerodigestive tract injuries occur in 23-30% of patients with penetrating neck wounds, and esophageal injuries are associated with mortality rates of 11-17%.

A retrospective study by Forner et al of adult patients indicated that compared with penetrating neck injuries, the in-hospital mortality rate is lower and the length of hospital stay is shorter for blunt injuries to the neck. The crude mortality rates were 4.9% versus 6.0% for blunt versus penetrating injuries, respectively, with adjusted analysis confirming that mortality rates for blunt injuries were decreased (odds ratio = 0.66) and that length of stay was significantly reduced (rate ratio = 0.92). ^[21]

Controversy persists regarding the ideal treatment of patients with penetrating neck trauma. Advocates of mandatory exploration of penetrating neck wounds believe that surgery is a time-tested management strategy that allows rapid diagnosis of potentially life-threatening injuries that may be missed on physical examination. A prospective study of 393 patients with stab wounds by Apeffelstaedt and Muller revealed that clinical signs were absent in 30% of neck explorations with positive findings and in 58% of those with negative findings. ^[22] They also reported a very low complication rate and a mean hospital stay of 1.5 days. The authors concluded that mandatory exploration is safe, does not prolong hospital stays, and prevents unnecessary diagnostic procedures.

Advocates of selective management cite the high rates of negative findings at neck exploration, which range from 30-89%. Additionally, other studies have revealed a prolongation of hospital stay by 1.4 days in patients with negative findings at exploration. Most centers have adopted a form of selective management instead of mandatory exploration, but the criteria for surgical intervention, as well as the protocols for diagnostic investigations, vary widely.