Traumatic Neck Injuries – Causes, Symptoms, Treatment

The management of neck trauma can be challenging and sometimes overwhelming, as this anatomical region contains many vital structures. These structures may pose a diagnostic and therapeutic dilemma in the emergency department.[rx][rx][rx]

Neck Anatomy

For descriptive and clinical management purposes, the neck is divided into three zones: zones 1, 2, and 3. In penetrating trauma, zone designations have anatomic, diagnostic, and management implications. Since the zone system is helpful in guiding management decisions, it is preferable to employ the zone system when describing traumatic injuries. Understanding of the anatomy of the neck, especially the location of important structures, is essential to providing optimal care.

Zone 1

• This is the area between the clavicles and the cricoid cartilage?. This zone contains vital structures which include the innominate vessels, the origin of the common carotid artery, the subclavian vessels and the vertebral artery, the brachial plexus, the trachea, the esophagus, the apex of the lung, and the thoracic? duct. Furthermore, surgical exposure and access can be difficult in this zone, because of the presence of the clavicle and bony structures of the thoracic inlet.

Zone II

• This is the area between the cricoid cartilage? and the angle of the mandible. The following structures are located here: the carotid and vertebral arteries, the internal jugular veins, trachea, and the esophagus. This zone has comparatively easy access for clinical examination and surgical exploration. It is the largest zone and the most commonly injured in the neck.

Zone III

• This is the area between the angle of the mandible and the base of the skull. This area contains the distal carotid and vertebral arteries and the pharynx. Since it is very close to the base of the skull, this area is less amenable to physical examination and difficult to explore during surgical evaluation.
• Anatomically, the neck is also described in triangles. The sternocleidomastoid muscle separates the neck into two triangles. The anterior triangle contains most of the major anatomic structures of the neck including larynx, trachea, pharynx, esophagus, and major vascular structures. The posterior triangle contains muscles, the spinal accessory nerve, and the spinal column.

Pathophysiology

The pathophysiology of neck injury depends on the mechanism of injury. The neck contains many critical organ systems adjacent to one another. It is for this reason that even innocuous-appearing wounds have the potential to cause either immediate or delayed life-threatening injuries or complications. It is rare to have a cervical? injury without a neurological deficit in patients with penetrating neck trauma.[rx]

With a low-risk National Emergency X-radiography Utilization Study I (NEXUS I) criteria, spinal cord injuries are unlikely to occur. These criteria obtain only if the patient is:

• Alert and awake
• Not intoxicated
• Has no signs or symptoms of neurologic injury
• Has no spinous process pain? when an area is touched or pressed. সহজ বাংলা: চাপ দিলে ব্যথা।" data-rx-term="tenderness" data-rx-definition="Tenderness means pain when an area is touched or pressed. সহজ বাংলা: চাপ দিলে ব্যথা।">tenderness?.

Zone 1 is a dangerous area and injuries in this region are potentially lethal. There is a potential for injury to the following important structures:

• Great vessels in the neck
• Mediastinum
• Cervical? and thoracic? esophagus

A high mortality rate accompanies zone 1 injuries. Vascular injuries are the most common of cervical? injuries and occur in up to 40% of patients with penetrating neck trauma. A vascular injury should be suspected in the presence of the following hard signs. (Hard signs suggest the presence of a serious injury that needs immediate attention or intervention).

Signs suggestive of vascular injury:

• Rapidly expanding or pulsatile hematoma
• Severe hemorrhage or difficult to control bleeding
• Shock refractory to fluid resuscitation
• Decreased or absent pulse
• Vascular bruit or thrill
• Neurologic deficit (On physical examination, this is suggestive of cerebral ischemia?)

Signs suggestive of esophageal injury:

• Massive hemoptysis
• Significant hematemesis
• Respiratory distress

The soft signs of penetrating neck trauma include minor hemoptysis, hematemesis, dysphonia, dysphagia?, subcutaneous, or mediastinal air, non-expanding hematoma. Beware that penetrating injuries involving zones 1 and 3 have a higher risk for occult vascular injury. Also, beware of the possibility of significant concurrent wounds in these zones to the head, chest, or abdomen. Suspect airway injury if dyspnea?, hemoptysis, subcutaneous air, stridor, hoarseness, and dysphonia are present. Esophageal injuries may not be clinically apparent initially. In addition, beware that normal radiographs do not exclude esophageal injury.

Causes of Traumatic Neck Injuries

Three major mechanisms have been described in neck trauma:

• Blunt trauma: This includes motor vehicle accidents and sports injuries. There may be delayed presentation of laryngeal, vascular, and digestive tract injuries if blunt trauma occurs. Also, beware that occult cervical? spine injury may be present in patients with blunt neck trauma. In addition, a shoulder harness (seatbelt) may also be responsible for shearing trauma to the anterior neck.
• Penetrating trauma: This comprises as much as 5% to 10% of all trauma injuries. Examples include gunshot wounds and stab wounds. It is the violation of the platysma that determines penetrating injury. Wounds which penetrate the platysma have the potential for severe injury. Consequently, it is wise to consider damage to the vital structures if the platysma is violated. Stab wounds involve low-energy penetration.
• Near-hanging or strangulation: External neck pressure causes cerebral hypoxia due to venous and arterial obstruction.

The most commonly injured area is zone 2, which can easily be accessed surgically. However, in zones 1 and 3 injuries, exposure and vascular control are more difficult to achieve.[rx]

Diagnosis? of Traumatic Neck Injuries

History and Physical

The most important part of the evaluation is a careful and thorough physical examination. Obtain essential information about the mechanism of injury, is vital. This should include responses the following considerations:

When: Timing of the injury

Where: Location of both the injury and number of wound sites (suspected entry and exit wounds), as well as their nearness to vital structures.

How: The type of wounding agent used, such as a knife, handgun, etc.

Events surrounding the timing of the injury: This information can be obtained from the emergency management report and the law enforcement report.

Any other existing or underlying medical condition(s).

It is important to determine the extent of the injury and identify any associated injuries. Beware that are uncommonly isolated injuries, particularly in cases involving blunt trauma. Always attempt to identify any associated injuries.

Evaluate the neck for hemorrhage, hematoma, ecchymosis, edema?, or any anatomic distortion. Auscultate for carotid bruits, stridor. Examine the neck for any pain? when an area is touched or pressed. সহজ বাংলা: চাপ দিলে ব্যথা।" data-rx-term="tenderness" data-rx-definition="Tenderness means pain when an area is touched or pressed. সহজ বাংলা: চাপ দিলে ব্যথা।">tenderness? or subcutaneous emphysema. The presence of certain findings provides clues for clinically significant vascular and aerodigestive injuries. Beware that signs and symptoms may be delayed. Bubbling or air emanating from a wound may suggest a tracheal injury. Crepitus may indicate that air has moved into the soft tissue space and should suggest prompt evaluation for injury to the trachea, esophagus, or pulmonary tree. A careful evaluation of the wound to determine the extent of the injury is required. Assess for penetration of the platysma. However, wounds should never be probed blindly, as this may cause uncontrolled bleeding. A full neurologic examination should also be performed.

Evaluation

Evaluation of neck injuries warrants notification of a trauma team or surgeon if either is available. Since physical examination may not be reliable in ruling out injuries in patients with neck trauma, one should consider a low threshold for obtaining additional imaging studies and/or a surgical consultation. Periodic examination is required to identify deterioration in clinical status as well as any ongoing. The value of a thorough secondary survey to evaluate for additional injuries cannot be over-emphasized in such patients. Diagnostic testing is performed for stable patients manifesting soft signs of injury and, sometimes even for those who are asymptomatic at initial presentation. [rx][rx]

Chest Radiography

Obtain anterior and lateral neck and chest radiographs in any patient presenting with significant neck trauma and look for hemothorax, pneumothorax, or pneumomediastinum. These should be obtained especially for patients with zone 1.

Angiography

Angiography is the initial study to evaluate for vascular injury. This may provide information about injuries to additional structures and may delineate the path of the projectile. Since it is less invasive, it is more commonly used to define vascular neck injury.

Conventional Angiography

A four-vessel angiography with venous-phase imaging has a sensitivity of greater than 99%. This is the “gold standard” for evaluating the vascular injury. If performed, should include the carotid and vertebral vessels, the intracranial portion of the carotid artery in zone 3 injuries, and the aortic arch with its branches in zone 1 injuries.

Duplex Ultrasonography

Duplex ultrasonography can be obtained in stable patients. It is noninvasive and relatively inexpensive, but it is operator dependent.  In addition, non-occlusive injuries may be missed if the flow is preserved, such as with intimal flaps and pseudoaneurysms. Its role in zone III evaluation is also limited.

Esophagography

Esophagography should be performed if an esophageal perforation is suspected.

Treatment of Traumatic Neck Injuries

Since the neck houses vital structures, prompt evaluation, and rapid intervention are required. The initial assessment should be performed according to the ATLS protocols. An immediate trauma service consultation should be obtained for patients with suspicion of vascular, tracheal, or esophageal injury.[rx][rx][rx]

Priorities in the management of patients with neck trauma are like those for any other patient with a life-threatening condition.  The primary priorities are securing the airway, maintaining ventilation, controlling hemorrhage, and treating shock.  At the same time, check vital signs and determine the stability of the patient. Patients with neck may have other life-threatening injuries that may take precedence.

Airway

As always, the priority is airway stabilization, particularly in patients with neck trauma, while maintaining cervical? spine immobilization. Remember that in-line stabilization should always be maintained when there is a concern for a cervical spine injury. Up to 10% of patients with penetrating neck injuries may present with airway compromise. Be aware that despite a stable initial appearance, airway compromise can ensue rapidly.

Beware that swelling?, distorted anatomy, and hematoma formation may contribute to impending airway obstruction in facial or neck trauma. Therefore, early airway control should be considered as the conditions may rapidly worsen.

Breathing

Evaluate the breathing and assess for any hemothorax or pneumothorax, particularly with penetrating zone 1 injuries

Circulation

A direct, simple pressure on the open wounds should be used to control bleeding in the emergency department. Wounds that have air sucking or bubbling should be covered with Vaseline gauze. No blind probing of the wound and no clamping of the vessels should occur in the emergency department. It is important not to occlude both carotid arteries or obstruct the patient’s airway. Avoid nasogastric tube placement in patients with penetrating neck injury because of the risk of hematoma rupture. The agitation of the patient during tube insertion may precipitate bleeding.

Further management of the patient with penetrating neck trauma depends on the anatomic zone of injury, clinical presentation, and hemodynamic stability. Determine the zone of injury, as this will determine evaluation and management strategy.

Zone 1

Since up to one-third of patients with a clinically significant zone 1 injury may have no symptoms at their initial presentation, many centers advocate vascular evaluation of the aortic arch and great vessels, with an esophageal evaluation.

Zone 2

This area has easier surgical access and poses a low risk for adverse sequelae from exploration. The decision for surgical exploration depends on the symptoms.

Symptomatic penetrating zone 2 injuries should undergo neck exploration.

Asymptomatic patients with penetrating zone 2 injuries may be treated with either mandatory exploration or directed evaluation and serial examinations.

Indications for an angiogram: a stable patient with persistent hemorrhage or neurologic deficits. The presence of Horner syndrome (sympathetic nerve plexus injury) and hoarseness (recurrent laryngeal nerve injury). This suggests a violation of carotid sheath.

Zone 3

In this zone, there is potential for injury to major blood vessels and the cranial nerves close to the skull base. Beware that patients with arterial injuries may be asymptomatic at their initial presentation, and surgical exposure and control of bleeding in this location may be quite difficult.  In addition, many vascular injuries are amenable to definitive treatment by an interventional radiologist. Therefore, the injury can be potentially treated in the same setting like the one in which the diagnostic angiogram is done.

Bottom Line

• Zones 1 and 3:  Difficult access, and exposure, vascular control may be challenging
• No mandatory exploration, however, angiography is suggested.

For Unstable Patients

All unstable patients with evidence of vascular or aero-digestive injury should receive further evaluation by performing an invasive intervention. These patients should be transferred to the operating room for definitive care depending on the type and location of injury as well as associated injuries.

For Stable Patients

1. Whether to perform mandatory exploration of all zone 2 injuries
2. Whether to obtain invasive intervention.in all zone 1 and 3 injuries

With improvements in multidetector  (angiography, “mandatory” neck exploration for platysma violation and “mandatory” arteriography for zones 1 and 3 injuries are falling out of favor. It is important that all patients with platysma muscle violation be admitted to the surgical service or the observation unit for ongoing observation, regardless of their stability.

Blunt Trauma

Up to 5% of traumatic injuries to the neck are due to blunt trauma. Motor vehicle accidents are the most frequent cause. It occurs when an unrestrained passenger may strike the neck on a dashboard or steering wheel.

Blunt trauma can damage the vessels by the following mechanisms

• Direct damage
• Excessive rotation and/or hyperextension: This causes stretching of the arteries and veins resulting in a shear injury.

It is often associated with other significant injuries. Beware that there are uncommonly isolated injuries, particularly in blunt trauma; therefore, always identify any associated injuries.

diagnosis?: Differential diagnosis is a list of possible conditions that may explain symptoms. সহজ বাংলা: একই লক্ষণের সম্ভাব্য রোগের তালিকা।" data-rx-term="differential diagnosis" data-rx-definition="Differential diagnosis is a list of possible conditions that may explain symptoms. সহজ বাংলা: একই লক্ষণের সম্ভাব্য রোগের তালিকা।">Differential Diagnosis?

• Injury to the spinal cord
• Strangulation

Complications

• Airway obstruction
• Aspiration
• Vocal cord paralysis
• Perforated esophagus
• Severe vascular injury
• Necrotizing infection
• Stroke?
• Air embolism?
• Pneumothorax, hemothorax