Penetrating Neck Trauma

Authors: Dennis Hanlon, MD, FAAEM, Vice Chairman, Academics, Department of Emergency Medicine, Allegheny General Hospital, Pittsburgh, PA; Rick J. Sumrok, MD, Senior Resident, Emergency Medicine, Allegheny General Hospital, Pittsburgh, PA.

Peer Reviewer: Perry W. Stafford, MD, FACS, FAAP, FCCM, Head, Pediatric Surgery, Jersey City Medical Center, Jersey City, NJ.

Penetrating neck trauma continues to be a challenging subset of trauma care. This area is loaded with potential high-risk injuries and controversies about the optimal management. The literature favors a more selective approach to these patients, however, the fundamental principles of resuscitation still apply because airway compromise and exsanguination are the greatest immediate life threats. This article reviews the medical literature on the diagnosis and management of these complex injuries.

– The Editor

Introduction

The management of penetrating neck trauma presents a significant challenge to emergency personnel. Penetrating injuries to the neck present a challenging diagnostic and therapeutic dilemma because the spectrum of injuries ranges from minor to acutely life threatening. Successful management requires a practical understanding of the anatomy of the neck and the tremendous number of vital structures in close proximity. A thorough diagnostic and management strategy must be implemented in the emergency department (ED) to avoid missing potentially devastating injuries. Optimal strategy remains controversial, and there remains substantial institutional variation.

Epidemiology

Although there has been a decrease of penetrating neck injury in the United States in the past years, it remains a significant public health concern.1 This is due to the epidemic numbers of firearm-related injuries from interpersonal violence that still occur, particularly in highly populated urban areas. Most injuries are secondary to stabbings or gunshot wounds. Penetrating neck trauma accounts for 5%-10 % of all traumatic injuries in some urban trauma centers.2-4 Most penetrating injuries to the neck involve zone II, which extends from the cricoid cartilage to the angle of the mandible. As with most penetrating trauma mechanisms, males are affected more commonly than females by approximately fourfold.2 Mortality from penetrating neck trauma ranges from 2% to 10%.2,3

In the neck, vascular structures are the important anatomical structure most often injured.2 Venous injuries occur more often than arterial injuries. The common carotid artery is the most common arterial injury, with the subclavian artery being the next most commonly injured.2 Laryngotracheal and esophageal injuries occur almost equally with esophageal injuries being less common.2,5

Historical Perspective

Historical accounts of penetrating neck injury date to antiquity. One of the first works involves an esophageal injury from a stab wound 5000 years ago.6 Ambrose Pare described the first repair of a cervical vascular injury.7 Both the common carotid artery and internal jugular vein were lacerated and subsequently ligated. The battlefield gave rise to many accounts and advances in diagnosis and management of penetrating neck trauma. During the Civil War, penetrating neck trauma management focused primarily on observation. Mortality rates were approximately 15%.8 World War I management also focused primarily on observation, although exploration and ligation became more prevalent. Mortality rates remained essentially unchanged. By World War II through the Vietnam conflict, mandatory exploration with vascular repair was the accepted practice.9 Although this strategy missed very few injuries, it resulted in numerous negative surgical explorations. Today's modern diagnostic capabilities have given rise to new management strategies, some of which focus on nonoperative management following diagnostic testing or observation alone.

Etiology

The etiology of penetrating neck injuries can be divided into three categories: gunshots, stabbings, and miscellaneous. Each category has different predisposing factors and injury patterns. Gunshot wounds and other high-velocity injuries generally produce greater damage and thus are more likely to require surgical exploration. Injuries from gunshots and stabbings most often have a clear etiology, and their epidemiological patterns vary according to causal factors (e.g., crime rates, hunting accidents, military activity). Concomitant injury patterns obviously must be diagnosed and managed. The miscellaneous category represents a broad spectrum of injury by various other penetrating objects — from automobile glass secondary to car collisions to impalement from airborne objects. Associated injury patterns can be as broad and unpredictable as the mechanism of injury itself.

The pediatric patient with penetrating neck trauma represents a unique management challenge. This type of injury is uncommon in the pediatric population, but the potential injuries and complications can be devastating.10 Literature on diagnosis and management regarding the pediatric patient is also scant. One study demonstrated motor vehicle collisions to be the most common mechanism of injury at 32.2%. Gunshot wounds and animal bites followed at 22.8% and 12.9%, respectively.10 A specific mechanism of concern is penetrating neck injuries from air-guns because physicians and other personnel may mistakenly consider BB gun injuries as somewhat trivial. Significant injuries have been reported, including an expanding spinal hematoma.11 Mortality rates were similar to the adult population. Zone II injuries were most common, a fact also seen in the adult studies.10 Associated injury patterns remain very broad, depending upon the mechanism of trauma and whether the injury is isolated or associated with multiple injuries.

Pathophysiology

The pathophysiology of penetrating injury is relatively straightforward. Traditionally, gunshot wounds are divided into low-velocity weapons (< 1000 ft/sec) and high-velocity weapons (>2500 ft/sec).12,13 Low-velocity weapons, which includes most handguns, tend to cause direct vascular injury. High-velocity weapons (e.g., hunting rifles and assault rifles) cause cavitation or disruption of tissue well removed from the tract. Types of direct vascular injury include intimal flap (most common), (Figure 1) transection, laceration, puncture, arteriovenous fistula, and pseudoaneurysm (Figure 2).12 Types of indirect vascular trauma include spasm, external compression, mural contusion, and thrombosis.12 Although the ballistics may be relatively straight forward, the path of the bullet may be difficult to predict.

Figure 1. Gunshot Wound to Zone II of the Neck

Figure 1. A 59-year-old man who attempted suicide by gunshot to zone II left neck. Lateral view from common carotid arteriogram confirms the pseudoaneurysm (thick arrow) and intimal flap (thin arrow).

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.


Figure 2. Arteriogram of Patient with a Stab Wound to the Neck

Figure 2. A 21-year-old man who presented with stab wound to right neck traversing zones I and II. Anteroposterior view from arteriogram shows pseudoaneurysm (arrow) of proximal right common carotid artery.

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.

The injuries from stab wounds are directly related to the characteristics of the weapon used, although the path and depth of penetration are often difficult to predict. Apparently minor wounds may be associated with significant underlying injuries.

Anatomy

The anatomy of the neck is complex. There are many important structures in proximity to each other. Traditionally, the neck is divided into three zones for the management of penetrating trauma. (See Table 1 and Figure 3.) Zone I extends from the sternal notch to the cricoid cartilage. Injuries to zone I have the highest mortality due to associated injuries to intrathoracic structures (Figure 4).2 Zone II lies between the cricoid cartilage and the angle of the mandible. Zone II injuries are the most common. Zone III consists of the upper neck above the angle of the mandible to the base of the skull. Surgical exposure is difficult in zones I and III.

Table 1. Anatomic Contents of the Zones of the Neck

 
Figure 3. Zones of the Neck

Illustration courtesy of Marcus Eubanks, MD.


Figure 4. Penetrating Trauma to Zone I of the Neck

Figure 4. A patient who presented following penetrating trauma to zone I of the neck.

Figure courtesy of Howie Werman, MD, FACEP, Professor of Clinical Emergency Medicine, The Ohio State University College of Medicine and Public Health; Medical Director, Med-Flight, Columbus, OH.

Another classification separates the neck into triangles. The sternocleidomastoid muscle is the anatomical landmark that divides the neck into anterior and posterior triangles.13 The anterior triangle lies between the anterior midline of the neck, the inferior aspect of the angle, and the anterior border of the sternocleidomastoid. The posterior triangle is bordered by the posterior aspect of the sternocleidomastoid, the middle third of the clavicle, and the anterior aspect of the trapezius. Injuries to the posterior triangle have a lower incidence of significant injuries than those to the anterior triangle.14

The fascial and muscle planes of the neck are extremely important in the evaluation of penetrating injuries. The platysma is a thin, broad muscle that originates from the deep fascia that covers the upper chest and inserts on the inferior aspect of the mandible.13 It is covered anteriorly by the superficial fascia and by the deep fascia posteriorly. Any violation of this muscle defines penetrating neck trauma and mandates surgical consultation. The deep fascial layers may help contain a hematoma. These fascial layers also may provide a route for spread of infection in case of injury, especially the pretracheal fascia, which connects to the anterior pericardium.2,4

Clinical Features of Penetrating Neck Trauma

Isolated penetrating neck injuries are uncommon. Penetrating neck injuries occur most often in the setting of multiple trauma.4 The presentation may range from relatively asymptomatic to dramatic and acutely life-threatening depending upon the structures involved. To avoid missing subtle findings, the search for injuries must be systematic. The history and physical examination should be directed to the areas of potential injury including vascular, laryngotracheal, esophageal, and neurological injuries.15

Vascular injuries occur in approximately 25% of patients with penetrating neck injuries.15-17 Exsanguination is the most common cause of immediate death after a vascular injury.17 Morbidity and mortality also result from hematomas compromising the airway, direct vascular injury with subsequent occlusion, and bullet embolization.17 Mortality from these injuries ranges from 5% to 50%.2,4,13,15 The clinical features of a vascular injury may be quite obvious, such as pulsatile bleeding or an expanding hematoma. These signs, believed to demonstrate a definite vascular injury, are referred to as "hard signs".2,13 (See Table 2.) Vascular injuries also may present with subtle neurologic or pulse deficits, therefore, a rapid yet vigilant exam is necessary. Late complications include traumatic aneurysm and arteriovenous fistula.5

Table 2. Clinical Features of a Vascular Injury

Laryngotracheal injuries complicate 10% of penetrating neck injuries.15,17 With penetrating trauma, these injuries are rarely occult.3 The most common signs and symptoms include dyspnea, stridor, dysphonia, hemoptysis, laryngeal tenderness, subcutaneous emphysema, and air bubbling from the wound.2,3,13,15 (See Table 3.) Any of the above findings mandate laryngoscopy.

Table 3. Clinical Features of Laryngotracheal Injury
• Hoarseness/ altered voice
• Anterior neck pain / tenderness
• Hemoptysis
• Stridor
• Subcutaneous emphysema / crepitance
• Deformity of neck landmarks
• Air bubbling from wound

Esophageal injury occurs less frequently than vascular or laryngotracheal injuries due to the relatively protected location of the esophagus.17 Some authors have noted dyspnea, hemoptysis, and air-bubbling through wounds as "hard signs" of aerodigestive tract injuries.18 Most esophageal injuries are associated with laryngotracheal injuries due to its location.5 Signs and symptoms of esophageal injury include dysphagia, oropharyngeal hemorrhage, nasogastric tube bleeding, subcutaneous emphysema, and resistance to movement of the neck. As with laryngotracheal injuries, crepitance is a strong indicator of esophageal injury.2,3,4,17-19 (See Table 4.) Despite these signs, esophageal injuries are the most commonly missed injuries in the neck.17,20 A delay in the diagnosis of these injuries increases mortality.13 An early diagnosis is required to prevent the development of mediastinitis due to para-esophageal contamination.

Table 4. Clinical Features of Esophageal Injury
• Dysphaglia
• Oral bleeding / nasogastric tube bleeding
• Anterior neck pain / tenderness
• Subcutaneous emphysema / crepitance
• Resistance to range of motion of the neck

Injuries to the nervous system include direct spinal cord injury, cranial nerve injury, peripheral nerve injury, and deficits in the central nervous system. Approximately 10% of patients with penetrating neck trauma will have an associated spinal cord or brachial plexus injury.13 The clinical presentation will depend upon the involved structure and the extent of the injury. In a recent study, almost 10% of asymptomatic patients with gunshot wounds to the trunk, head, or neck had spinal injuries.21 This percentage is much higher than had been reported in previous studies, and its results have been challenged.22,23 In Connell's study, no spinal injuries were found among nonintoxicated patients with a normal neurological examination who had penetrating trauma.22 Also, the presence of a peripheral nerve injury should alert the evaluating personnel to the possibility of an associated arterial injury because most nerves are located close to large arteries.5

Diagnostic Studies

A successful diagnostic approach to penetrating neck injury must include evaluation of the three individual organ systems: vascular, laryngotracheal, and para-esophageal. Also, the nervous system, such as the spinal cord/column and nerves and nerve root, must be evaluated. The venous structures that may be potentially injured include the internal and external jugular veins along with the subclavian veins. Arteries at risk of injury include the carotid, subclavian, and vertebral arteries. The vertebral artery is the least injured due to its well-protected position.13,17 Visceral structures with injury potential are the pharynx, larynx, trachea, esophagus, and pleural cavity.

If the integrity of the platysma muscle is not compromised throughout the entire wound and the physical examination is otherwise normal, one can assume no serious penetration occurred. No further tests need be performed to detect internal injury due to penetrating trauma. Any violation of the platysma indicates penetrating neck trauma has occurred and mandates both surgical consultation and further diagnostic evaluation. The hemodynamically unstable patient may require immediate operative exploration. As discussed in the historical perspective, the management has evolved from mandatory exploration to a more selective management if the patient is stable.2,13 This evolution has not been without controversy. Some authors have advocated a mandatory exploration of all significant penetrating neck trauma to avoid missing any important injuries. This approach yields a range of 30% to 89% negative explorations.24-28 This high negative exploration rate has produced the selective management of penetrating neck trauma. Currently, the controversy focuses on the selection of diagnostic testing needed to exclude the potential injuries.13 The choice of diagnostic tests will depend upon the resources available at an individual institution.

Advanced imaging technologies have enabled the detection of vascular and other injuries in penetrating neck trauma. Diagnosing vascular injuries remains paramount in penetrating neck trauma. Angiography has traditionally been considered the gold standard in evaluating such injuries (Figure 5). However, it is an invasive study and is not without risk. At the other end of the diagnostic spectrum, some have advocated the use of physical examination alone. Generally, it is believed to be insufficient.29 Bishara documented that almost 25% of vascular injuries were missed when relying on physical examination alone.29 Mohammed and colleagues reported a negative predictive value of 67% for the absence of signs of vascular injury on physical exam in patients with gunshot wounds to the neck.30 Diagnostic studies are clearly required to exclude potentially life-threatening injuries. Recently, noninvasive techniques have emerged, such as computed tomographic angiography (CTA), magnetic resonance angiography (MRA), and color flow ultrasound (US).

Figure 5. Common Carotid Arteriogram in a Patient with a Zone III Penetrating Injury of the Neck

Figure 5. A 22-year-old man with gunshot wound to zone III right neck in whom neurologic examination findings were normal. Lateral view from common carotid arteriogram confirms total occlusion (arrow) of internal carotid artery.

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.

In patients who are not deemed to require emergent surgical intervention, four main imaging modalities are considered: angiography, MRA, US, and CTA. MRA has been used for imaging vascular injuries. However, it is limited in the assessment of bony structures. In addition, it is not practical in the acute assessment of the trauma patient because of the need for proper monitoring and MR-incompatible equipment. The availability of emergent MR also is limited in many hospitals and trauma centers. Thus, MRA will not be further discussed. However, MR/MRA (Figure 6) remains a potential diagnostic modality if it becomes more efficient and more readily available.

Figure 6. MR Imaging of Zone II Penetrating Trauma


Figure 6a. A 14-year-old boy with gunshot wound across zone II who presented as C4-level quadreplegic. Axial T1-weighted MR image shows horizontal fracture extending through vertebral body and both transverse foramina. Note normal signal void in right vertebral artery (arrow) but lack of flow void in region of left vertebral artery (arrowhead).

  Figure 6b. A 14-year-old boy with gunshot wound across zone II who presented as C4-level quadreplegic.Coronal maximum-intensity-projection image from two-dimenstional time-of-flight MR angiogram, acquired with axial slices, reveals absent flow-related enhancement of left vertebral artery beyond origin consistent with occlusion (short arrow). Also note external compression of right vertebral artery at level of fracture (long arrow).
Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.

Color flow US offers a viable noninvasive alternative to angiography. US allows a noninvasive evaluation of the vascular bundles and adjacent tissue and a real-time analysis of blood flow velocity (Figure 7). US, like MRA, does have several significant limitations: It requires a trained technician and is highly operator dependent. In many hospitals, US is not available at night or on weekends. Imaging artifact may be generated by bone, and examination of smaller arterial branches may cause errors. Studies have been promising in the use of US, however, and its sensitivity was approximately 90%-91% compared with angiography, and its specificity was 100%.31 Positive predictive value was found at 100%, and negative predictive value was 99%.31 In spite of these encouraging numbers, the limited availability of US and the inter-operator variability make US less feasible in the reliable evaluation of vascular injury in penetrating neck trauma. Also, US may be misleading in zone III due to artifact.32

Figure 7. Sonogram of Penetrating Trauma to Zone II of the Neck

Figure 7 A 59-year-old man who attempted suicide by gunshot to zone II left neck. Longitudinal color sonogram of left common carotid artery shows pseudoaneurysm (PSA) with partial thrombus (T) and intimal flap (F).

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.

Helical CT angiography has been studied at several centers and has shown very promising results (Figure 8). Its sensitivity and specificity compared with angiography was 90%-100%. Munera and colleagues demonstrated a sensitivity of 90%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 98%.33 Several other studies have shown similar results making helical CT angiography an attractive alternative to standard angiography.34-36 In addition, CT may reveal aerodigestive injuries, bony injuries, and the tract of the bullet. When combined with physical examination, CT can reveal damage to the spinal column and spinal cord (Figure 9). There is no evidence that a negative CT study will exclude aerodigestive injuries, although it may sometimes diagnose these injuries. Some of the limitations of CTA include motion and foreign body artifact. Vascular abnormalities or congenital anomalies may be confused with pathologic lesions. Subclavian arteries may not be adequately visualized due to the imaging plane in some CT scanners, but greater spatial resolution in machinery is overcoming this deficit. Small lesions of questionable significance may be missed. Lastly, CT imaging is only diagnostic, and not therapeutic such as angiography. Nevertheless, CT imaging to detect vascular injuries remains an excellent choice in the initial assessment of vascular injury in penetrating trauma (Figures 10 and 11). Depending on the CT result, angiography may be indicated for confirmatory testing or intervention.

Figure 8. Penetrating Trauma to Zone III of the Neck

Figure 8. A 22-year-old man with gunshot wound to zone III right neck in whom neurologic examination findings were normal. Axial helical CT angiogram reveals normal enchangement in right internal carotid artery (solid arrow) and no enhancement in region of left internal carotid artery (clear arrow), indicating occlusion.

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.


Figure 9. Axial Helical CT Angiogram

Figure 9. A 14-year-old boy with gunshot wound across zone II who presented as C4-level quadreplegic. Axial helical CT angiogram filmed in bone windows shows path of bullet and fractures across C4 vertebral body involving both transverse foramina. Note contrast-enhanced right vertebral artery (white arrow) and nonvisualization of left vertebral artery (black arrow) in left transverse foramen.

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.


Figure 10. Penetrating Trauma of Zone I and II of the Neck

Figure 10. A 21-year-old man who presented with stab wound to right neck traversing zones I and II. Axial slice from helical CT angiogram reveals irregular contour of proximal right common carotid artery with contrast material extending outside confines of vessel lumen (large straight arrow) corresponding to site of pseudoaneurysm formation. Note hematoma surrounding artery (small arrows) and fracture through right lobe of thyroid gland (curved arrow).

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.
 
Figure 11. Axial Helical CT Angiogram of Patient with a Dog Bite to the Neck

Figure 11. A 34-year-old man who presented with a dog bite to zone II of left neck. Axial helical CT angiogram shows focal filling defect in left common carotidy artery (arrow).

Reprinted with permission from the American Journal of Roentgenology. LeBlang SD, Nunez, DB Jr. AJR 2000;174:1269-1278.

Evaluation of the aerodigestive structures of the neck, specifically the laryngotracheal and para-esophageal systems, requires the same rigorous approach as mandated for vascular injury. Injuries may be silent initially, and serious complications can result. Careful clinical examination remains the focal point in the diagnosis of aerodigestive tract injuries. Demetriades and colleagues propose that in awake, alert patients who are able to be evaluated clinically, physical examination alone can exclude or raise suspicion for significant injuries.37 In another study, all patients eventually proven to have an injury to aerodigestive structures were initially symptomatic.17 In a study with contrarian results, Gonzales and colleagues reported 4 esophageal injuries that were missed by a combination of physical examination and helical CT study.38

As in vascular injury, a chest and lateral neck radiograph should be a standard initial tool in the aerodigestive system evaluation. Flexible fiberoptic endoscopy is the desired modality for identifying laryngotracheal trauma. CT scanning of the neck can reveal laryngeal structural damage and fractures and dislocations of bone and cartilage. However, a negative CT study does not exclude aerodigestive injury. The evaluation of the esophagus and pharynx is not as straightforward as the laryngotracheal system. While the evaluation of the pharynx can be done via direct endoscopy with satisfactory results, the cervical esophageal evaluation remains much more complex, especially compared with the thoracic and abdominal esophagus. Flexible endoscopy has a lower sensitivity in the cervical region than compared with other esophageal areas, thus injuries may be missed in this area. Radiological imaging may be performed in the form of a swallow study or, in the case of intubated patients, with contrast injected via a tube. Sensitivities vary widely in radiological imaging from 60% to 100%, while sensitivity with endoscopy ranges in the 80th percentile in the cervical esophagus.39-42 Rigid endoscopy provides a higher sensitivity, but it must be done by experienced operators under general anesthesia. The combination of endoscopy and esophagoscopy has a synergistic ability to diagnose para-esophageal injuries. Demetriades and colleagues recommend this approach in the evaluation of the pharynx and esophagus in penetrating neck trauma.37

As previously mentioned, literature in the management of pediatric penetrating neck injury is sparse. One retrospective study done by Abujamra and Joseph examined 31 children with penetrating neck trauma.10 Most had only minor physical examination findings and did not merit exploration or diagnostic imaging. Observation alone was sufficient for the stable patient. Larger multicenter studies are needed before specific conclusions can be made; however, currently, the overall management of penetrating cervical injuries in children should follow the adult guidelines above.

Management

The initial management of a patient with penetrating neck trauma is similar to any potential major trauma patient. Of primary concern in a patient with this type of injury is airway compromise and extensive bleeding. The status of the airway can deteriorate precipitously due to edema and bleeding. The primary survey is rapidly performed with concurrent evaluation and management using a team approach if such resources are available. Supplemental oxygen should be provided, monitoring performed, and vascular access should be established. This access should be established on the opposite side of the injury.

Airway and Breathing

Airway management in penetrating neck injury patients is potentially very problematic. Approximately 10% of these patients will present with airway compromise, either partial or complete.5 There is not a universal consensus for either the indications for active airway management or the appropriate technique. The emergency medical literature in this area is somewhat scarce.

Orotracheal Intubation. Early intubation has been the rule if there is any question of airway compromise or anticipated problems. Orotracheal intubation using a rapid sequence intubation (RSI) technique is the method of choice in most patients with penetrating neck trauma. Concerns with using RSI in the patient with a neck injury include the difficulties or failure to intubate due to anatomic distortion and the potential conversion of a partial laryngotracheal injury into a complete transaction.43 Mandavia and colleagues reported a 100% success rate with this technique.43 Awake intubation is often recommended due to these potential complications. Despite these concerns, in one retrospective study, three cases had failure of fiberoptic intubation, yet these patients were successfully intubated using an RSI technique.43

Nasotracheal Intubation. Nasotracheal intubation has been relatively contraindicated in penetrating neck trauma due to concerns of dislodging a hematoma and lack of visualization of the airway. A prehospital study demonstrated a 90% success rate in a well-trained emergency medical services system.44 Also, these patients did not experience any complications related to this technique of airway management.44 Despite previous concerns, blind nasotracheal intubation may be a reasonable alternative for airway management by appropriately trained personnel in patients with penetrating neck trauma. Further study in this area is required.

Fiberoptic Intubation. Fiberoptic intubation may be considered in the management of these patients. This technique is time consuming and difficult if the airway is bloody. Awake fiberoptic intubation is considered the safest technique in cooperative patients with suspected airway injury at some trauma centers.45 Desjardins reports that his trauma center uses a rapid sequence technique with fiberoptic intubation in uncooperative patients who did not appear difficult to intubate.45

Direct Intubation. Direct intubation into the distal segment of an injured larynx may be possible in penetrating trauma. The trachea is held with hemostats, tracheal hook, or towel clip, and the endotracheal tube is placed directly into the trachea. Placement of an endotracheal tube through the wound is not universally successful depending upon the characteristics of the wound. A gum elastic bougie has been used to establish the airway through the wound in such a case.46 This device is usually used as an airway adjunct when the laryngoscopic view is suboptimal. The bougie is passed to the cords without direct visualization. If it finds the trachea, a clicking can be felt from the tracheal rings. This device also may become caught at the carina, and the resistance ensures tracheal insertion.46

Cricothyrotomy. Cricothyrotomy may be used as a rescue method if the injury is above the level of the cricothyroid membrane. Also proceed with this technique if the patient's condition does not allow time for a tracheostomy.

Tracheostomy. Tracheostomy may be used as a rescue method and usually will be performed by surgical colleagues. It should be performed at least one tracheal ring below the level of the injury.45

The method of stabilizing the airway will depend upon the skills of the practitioners available, the condition of the patient, and the resources of the institution.

Circulation: Hemorrhage Control. Direct pressure is used to control bleeding. Clamping of vessels should be discouraged. Wounds should be covered with an airtight dressing because lacerations involving the venous system may lead to air embolus.2 Fluid resuscitation and blood product replacement should follow standard guidelines.

Diagnostic Strategies

After stabilization, the initial key question is: Does the wound penetrate the platysma? If the answer is yes, a surgical consultation is mandatory. (The penetration of the platysma defines penetrating neck trauma.) The next question is: Should these wounds be managed with mandatory operative exploration or selective operations? The approach will vary by hemodynamic stability, the zone involved, mechanism of injury, and institution. Definite signs and symptoms of vascular or aerodigestive injuries requires urgent operative intervention.4,13 (See Table 5.)

Table 5. Absolute Indications for Mandatory Exploration
• Airway compromise
• Extensive subcutaneous emphysema
• Pulsatile hematomas
• Shock or active, uncontrollable bleeding

Unless the patient is very unstable, zone I and zone III injures are managed selectively due to the difficulties in examining these areas as well as obtaining good intra-operative exposure.13 The controversy primarily concerns the management of a stable patient with a zone II injury and no significant symptoms. Most experts favor selective management over mandatory exploration.4,13 All such patients should have a chest x-ray and soft-tissue neck radiography both anterior-posterior and lateral views in addition to the routine trauma laboratory studies. Patients with zone I injuries often have an associated pneumothorax or hemothorax. After these initial tests are performed and stabilization is obtained, the management of the stable patient with penetrating neck trauma proceeds based upon the involved zone, the mechanism, and the resources available.

Stable patients with a zone I injury require studies of the great vessels, airway, and esophagus. An arteriogram is performed to exclude great vessel injury. Bronchoscopy will identify laryngotracheal injuries. The combination of esophagram and esophagoscopy may evaluate potential esophageal injuries.

A stable patient with a zone II injury may require studies of the great vessels, airway, and esophagus. These patients are managed based on the mechanism and the presence of signs or symptoms of injury. A patient with transcervical wounds (wounds that cross the midline) is explored if symptomatic and undergoes selective management if asymptomatic. Some trauma centers practice expectant management of asymptomatic zone II injuries caused by stab wounds or low-velocity gunshot wounds.13 Patients with zone II injuries have a lower mortality rate because the access for surgical exploration is good and direct pressure can control hemorrhage. 46

A stable patient with a zone III injury requires studies of the cerebral circulation, upper airway, and esophagus. Ferguson and colleagues have questioned the need for an angiogram in patients with zone III injuries lacking hard signs of vascular trauma.47 All symptomatic patients with zone III injuries require diagnostic evaluation of the esophagus and arteries.2

Disposition

All patients with penetrating neck wounds—which by definition violate the platysma—require admission to a qualified surgeon with appropriate resources, preferably at a trauma center. A facility that does not have adequate resources should have transfer guidelines in place with a trauma center to facilitate transfer. ED physicians should be familiar with their facility's resources and should transfer patients, following stabilization, as appropriate.

Summary

Injuries to the neck present a difficult challenge in both diagnosis and management (See Table 6.). Successful management requires a thorough understanding of the complex anatomy of the neck. Clinical presentations and physical examination findings also must be reviewed. Some injuries may present dramatically and catastrophically, while others may be more insidious. A thorough and structured approach must be implemented for every patient.

Table 6. Pearls and Pitfalls
• Never clamp vessels in the neck.
• Don't probe neck wounds.
• Don't remove impaled objects.
• Earlier intubation is often the safest choice.

The controversy over mandatory exploration versus selective, nonoperative management is being replaced by discussion about the optimal nonoperative strategy for each zone realizing which structures are at risk for injury. Selective evaluation is based on the symptoms and physical findings, unlike routine imaging in which all patients undergo a complete battery of studies. The diagnosis of injuries in penetrating neck trauma should focus on evaluating vascular, laryngotracheal, and esophageal trauma. Spinal cord and other nervous system trauma must not be overlooked, although there is some controversy about its prevalence.21-23 Similar to adults, the selective management of penetrating neck injuries is a safe, effective strategy in the pediatric population in an experienced pediatric trauma center.48

Angiography remains the gold standard for vascular injury diagnosis, but newer imaging modalities—primarily helical CT angiography— provide an excellent alternative for initial screening and soon may become the primary imaging modality. MRA and US offer comparable results, but these diagnostic tools are not as practical in the acute injury setting due to operator dependency and limited after-hours availability. Aerodigestive injury can be suggested from physical examination findings, but the combination of endoscopy and esophagography along with bronchoscopy provides a reliable diagnostic modality to identify or rule out esophageal and laryngotracheal injury.

References

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