Laboratory Studies
For any patient thought to have a neck injury, obtain the standard trauma blood studies (CBC count, electrolytes, other warranted blood chemistry levels, blood type and crossmatching).
Generally, a CBC count and blood typing suffice in a previously healthy individual, but patients with comorbid disease or those in shock may require additional studies, including a determination of coagulation profiles.
Obtain alcohol and toxicology screens, when indicated.
Imaging Studies
Any imaging study is associated with delay, and transport to the operating room should not be delayed when the patient's condition warrants emergent surgery. Determining the specific study and order of testing depends on institutional preferences, mechanism of injury, and the clinical scenario. Detection of pharyngoesophageal injuries poses many problems, requiring a high index of suspicion. The failure to diagnose these injuries can lead to significant morbidity and mortality. [11, 15, 25, 26]
Cervical radiography
Unless indicated otherwise, most patients who have sustained significant injury to the neck require plain-film radiography. [25] Although not helpful in most cases of vascular or related soft tissue injury to the neck, anteroposterior (AP) and lateral films may help localize a foreign body. However, in many trauma centers, helical CT scans are supplanting plain cervical films for all patients with significant neck injuries.
Review the cervical radiographs for emphysema, fractures, displacement of the trachea, and presence of a foreign body (eg, missile fragments).
Chest radiography
Any finding suggestive of a zone I wound or damage to the thoracic cavity mandates obtaining a chest radiograph.
Circumspectly review the film for hemothorax, pneumothorax, widened mediastinum, mediastinal emphysema, apical pleural hematoma, and foreign bodies.
Open injuries bring the greatest risk of foreign body contamination. Commonly encountered materials include gravel debris, glass fragments, wooden splinters, and metal particles. Foreign body presence is obvious in some injury patterns, but others may not suggest contamination with foreign body materials. Foreign objects that have not been detected and removed introduce risk of severe wound infections and chronic wound healing disorders. Besides these severe health issues, medicolegal consequences should be considered. Although accurate clinical examination is the first step for the detection of foreign body materials, choosing the appropriate radiologic imaging is decisive for detection or non-detection of foreign material. When impaired wound healing continues over time, the presence of an undetected foreign object must be considered. [27]
Supplementary tests
Obtain supplementary tests in the stable patient if specific system injuries are suggested by the history, physical, or prior ancillary studies. Additional imaging studies include CT, MRI, color flow Doppler studies, contrast studies of the esophagus, interventional angiography, and endoscopic images.
CT scans prove most useful when bony or soft tissue damage is a consideration. Requesting a CT scan of the neck when a laryngeal fracture is suspected is especially important because clinically subtle injuries of the larynx often escape detection but become readily identifiable on CT scan.
Although conventional angiography remains the criterion standard for evaluation of vascular trauma in the neck, CT angiography (CTA) offers advantages. [15, 26] CTA is readily accessible in most centers, can be rapidly performed, and causes fewer complications. Additionally, some experts assert that subtle disruptions of the vessel wall that are difficult, if not impossible, to detect on angiography (if they are not prominent enough to alter the contrast column) may be detected on CTA through planar reconstruction. [28, 29, 30, 31, 32, 33]
Penetrating neck injury can have potentially devastating consequences because many vital structures are contained within the neck. In patients who do not require immediate surgery, CTA of the neck is the test of choice for characterizing the injury. A systematic approach to assessment will ensure thorough evaluation and give the reporting radiologist the best chance of identifying significant findings, which can often be subtle. Clear communication with the trauma team is needed at the time of the request and after imaging has been evaluated; relaying significant findings to the team is vital for ensuring the best patient outcomes. [34]
CTA alone may not be sufficient to exclude esophageal injuries in penetrating neck trauma. Because delayed diagnosis is associated with increased morbidity, additional diagnostic interventions should be undertaken if the clinician is concerned about esophageal injury. [35]
In addition to providing visualization of traumatic vascular lesions such as partial or complete occlusion, pseudoaneurysm, dissection, intimal flaps, and traumatic arteriovenous (AV) fistulas, CTA additionally provides useful information about the cervical soft tissues, aerodigestive tract, spinal canal, and spinal cord. Artifacts secondary to metal, specifically bullet fragments, which can obscure vascular detail, can limit CTA. Likewise, shoulder artifacts may limit diagnostic information from CTA. In these cases, angiography is necessary for optimal assessment. [28, 36, 37]
In 23 patients with penetrating injury and hard signs, the addition of CTA to the management of hemodynamically stable patients significantly decreased the rate of negative neck explorations without increasing missed injury rate. Sensitivity, specificity, positive predictive value, and negative predictive value for CTA in the presence of hard signs were found to be 83%, 100%, 100%, and 94%, respectively. [29]
Consider an emergent MRI and/or magnetic resonance angiography for evaluation of the patient exhibiting neurologic impairment with minimal or absent abnormalities on plain radiographs of the cervical spine.
Some institutions now substitute color flow Doppler ultrasonography or use it as a screening test in low-risk patients or those thought to have a carotid injury. However, its sensitivity remains variable (especially with zone I and zone III injuries), and its use is controversial.
Duplex ultrasonography can be obtained in stable patients. However, this noninvasive and relatively inexpensive modality is operator-dependent. In addition, non-occlusive injuries may be missed if flow is preserved, as occurs with intimal flaps and pseudoaneurysms. The role of this imaging approach is limited in zone III evaluation. [3]
Although a normal Gastrografin study occasionally proves useful in the evaluation of the cervical esophagus, it does not rule out a pharyngoesophageal leak. Deciding which contrast agent to use when studying the esophagus remains a subject of dispute among the experts. Advocates for Gastrografin use note that it is less likely than barium to cause an inflammatory response if extravasation through a breach occurs. However, barium induces less inflammation in the lungs; therefore, it poses less of a risk in the patient predisposed to aspiration.
Esophagography should be performed if an esophageal perforation is suspected. [3]
Procedures
Endoscopy
Laryngoscopy, bronchoscopy, pharyngoscopy, and esophagoscopy may be useful in the assessment of the aerodigestive tract. Rigid endoscopes are superior to flexible scopes.
Before inserting any scope, confirm that the airway is patent, intact, and protected (usually ensured by placement of an endotracheal tube). Ecchymosis of the posterior or lateral pharyngeal wall implies concealed neck damage.
Endoscopy, especially indirect laryngoscopy, often becomes problematic in the apprehensive trauma patient, and it may be best to defer examination until the airway is protected and the patient is anesthetized.
Angiography
Angiography routinely is used to evaluate stable patients sustaining penetrating wounds to zones I and III that pierce the platysma. Angiography remains preferred over alternative contrast studies because angiography is less likely to obscure vascular damage.
A 4-vessel study is a prerequisite.
Preoperative arteriograms facilitate operative decision making, particularly when a question of intrathoracic involvement exists (such as with zone I injuries necessitating a thoracotomy). Otherwise, consider confirming adequacy of the collateral circulation if carotid artery ligation is contemplated (as may be necessary in zone III arterial wounds).
Occasionally, surgical exposure and access to bleeding vessels proves challenging, if not unattainable or impractical, and selecting therapeutic embolization or occlusion of the harmed vasculature remains a better option. This is achieved by placing an intravascular balloon tip catheter or shunt. However, discretion is critical because forceful placement of a catheter or shunt may dislodge a clot (eg, causing a stroke) or may risk causing or exacerbating intimal damage, and even risk inauspicious perforation of the blood vessel.
Drawbacks include cost and the inherent danger of any vascular, particularly arterial, invasive procedure.
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Neck trauma. Zones of the neck.
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Neck trauma. Zone I injury.
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Neck trauma. Zone II injury.
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Neck trauma. Zone III injury.
