Neck trauma

Anatomy

• Posterior triangle
  • Anterior border of trapezius, posterior surface of SCM and middle third of clavicle
• Anterior triangle
  • Borders of SCM, inferior mandible and midline of neck
  • Contains most vital structures
  • Zone I – Clavicles to cricoid cartilage
  • Zone II – Cricoid cartilage to angle of mandible
  • Zone III – Angle of mandible to base of skull
  • Historically, zone II get mandatory surgical exploration and I/III get further diagnostic evaluation
  • 50% of penetrating injuries cross multiple zones and trajectory can be difficult to identify

Anatomy

• Zone I
  • Proximal carotid/vertebral vessels
  • Major thoracic vessels
  • Superior mediastinum
  • Lungs
  • Oesophagus
  • Trachea
  • Thoracic duct
  • Spinal cord

Anatomy

• Zone II
  • Carotid and vertebral arteries
    Jugular veins
  • Oesohpagus
  • Trachea
  • Larynx
  • Spinal cord
• Zone III
  • Distal carotid and vertebral arteries
  • Pharynx
  • Spinal cord

Anatomy

• Penetration of platysma = deep wounds
• Wounds that do not penetrate platysma are NOT life threatening
• Deep fascia beneath platysma prevents exsanguination but can lead to airway compromise from raised pressures as well as conduits for infection to the mediastinum
• Includes investing, pretracheal, prevertebral and carotid sheath fascia

Airway

• Indications for early intubation
  • Stridor
  • Respiratory distress
  • Obstruction from blood/secretions
  • Expanding neck haematoma
  • Profound shock
  • Extensive subcutaneous emphysema
  • Altered mental status
  • Tracheal shift

Airway

• Relative indications for early intubation
  • Progressive neck swelling
  • Voice change
  • Progressive symptoms
  • Massive subcutaneous emphysema of the neck
  • Tracheal shift
  • Altered mental status
  • Expanding neck haematoma
  • Need to transfer
  • Symptomatic patient with anticipitaed prolonged time away from ED

Airway

• Assume difficult airway in all cases
• RSI oral intubation is 98% successful
• Can consider awake intubation if difficult BVM or video laryngoscopy
• LMA is a bridging device but is relatively contraindicated in distorted airway anatomy
• Surgical or needle cric is plan D (or sometimes plan A)
  • Needle if <8yo and preferred if <12yo

Breathing

• Pneumothorax and haemothorax seen in 20% of penetrating neck trauma

Circulation

• Exsanguination is the most common cause of death in penetrating neck injury
• Massive bleeding from trauma kills more rapidly than unstable airway
• If not controlled by simple pressure, insert a Foley catheter into the wound and inflate until bleeding stops or resistance felt
• Haemostatic dressings combined with direct pressure may decrease blood loss and improve patient survival
• If not controlled – urgent surgery
• If subclavian vessels involved, uncontrolled zone I injury may require emergent thoracotomy

Disability

• Unstable C-spine injury is uncommon in awake patients with isolated penetrating neck injury
• C-spine collar placement may in this situation actually be counter-productive due to obscuration of view of wound and difficulty in haemorrhage control and intubation
• After gunshot wound, C-spine/spinal injury is more common so can place collar after neck examined for penetrating wound, vascular bruits or bleeding/haematoma
• Blunt neck trauma requires cervical spine immobilisation from arrival

Initial radiology

• CXR then multidetector CT angiography

Diagnosis

• Check depth of wound (platysma)
• Ask to cough (haemoptysis), swallow saliva (dysphagia) and speak (laryngeal fracture) if able
• In penetrating neck trauma, careful exam is 95% sensitive for detecting significant vascular and aerodigestive tract injuries
  • Oesophageal and venous injuries most commonly missed
• 90% of patients with hard signs will have injury requiring repair and should be rapidly transferred to OT or angiography suite
• Soft signs warrant further investigation but only a minority will have a significant injury

Penetrating neck injury

• 1% of traumatic injuries but 10% mortality rate
• Vascular injuries are the most common cervical injury and leading cause of death
• Historically, all zone II went for mandatory surgical exploration but in the era of MDCTA this has changed
• All unstable patients go to OT or interventional angiography
• If stable
  • Injury does not violate platysma – Observation
  • Injury violates platysma and hard signs exist – OT or interventional angiography
  • If injury violates platysma and no hard signs – MD CTA
    • If suspicion for pharyngo-oesohpageal injury – Oesophagogram + oesophagoscopy 100% sensitive
    • If suspicion for laryngotracheal injury – Panendoscopy
    • If suspicion for vascular injury – OT or interventional angiography

Penetrating vascular injuries

• Seen in 40% of penetrating neck injury
• Arterial injuries make up 45% of penetrating neck vascular injuries and usually involve the carotid artery (most frequent cause of death)
• Carotid artery injury
  • 15% stroke
  • 22% death
• Venous injuries seen in 20% of patients with penetrating neck wounds
  • Difficult to appreciate on exam
  • Most do not require operative repair
• 1/4 of those with soft signs only will have injury on CTA but only 3% undergo vascular repair

Penetrating vascular injury

• MDCTA if first-line
• Angiography performed if inconclusive
• Disadvantages of angiography
  • Cannot evaluate non-vascular neck structures, limited availability, contrast-induced nephropathy, mobilisation of additional personnel, have to leave ED, puncture site haematoma, thrombosis, embolism, vascular spasm, ischaemia and arterial dissection
• Colour flow doppler
  • Highly sensitive for clinically important injuries
  • Can be performed in ED, non-invasive, no radiation and decreased capital expense
  • Disadvantages – Cannot scan through subcut emphysema, cannot scan intrathoracic or intracerebral vessels, interoperative variability and limited availability

Blunt neck injury

• 5% of traumatic neck injuries
• MVA, assault, pedestrians struck by vehicles, falls and hanging
• Vascular injury seen in only 1% of blunt neck injuries
• Aerodigestive injuries are very rare
• Airway occlusion rather than haemorrhage is the most rapidly fatal injury

Blunt cerebrovascular injury

• Mortality rate of blunt cerebral vascular injury is around 60%
• Mostly initially asymptomatic and do not develop neurology for hours/days
• Angiographic screening of patients at risk can increase diagnostic rate by 10-fold
• Early identification and treatment reduces the rates of stroke and death
• 20% occur without an established risk factor
• Screening criteria (see over)
• Mechanism is cervical hyperextension and rotation or hyperextension during rapid deceleration
• Results in intimal dissections, thromboses, pseudoaneurysms, fistulas and transections
• Intimal tears lead to thrombosis with subsequent embolisation, stenosis, occlusion or pathway for dissection

BCVI – Denver modification

• Signs and symptoms
  • Arterial haemorrhage from nose, neck or mouth
  • Cervical bruit <50yo
  • Expanding cervical haematoma
  • Focal neuro deficit: TIA, hemiparesis, vertebrobasilar symptoms, Horner’s
  • Stroke on CT
  • Neurological deficit unexplained by head CT

BCVI – Denver Modification

• Risk factors: High-energy MOI with any one of:
  • LeFort II/III, mandible, frontal skull or orbital fracture
  • C-spine subluxation/transverse foramen involvement or C1-3 fracture
  • Any basilar skull fracture or occipital condyle #
  • Petrous bone fracture
  • DAI with GCS <9
  • Concurrent traumatic brain and thoracic injuries
  • Neck hanging with anoxic brain injury
  • Clothesline type injury with significant swelling/pain or altered LOC

BCVI

• Biffl et al. for blunt carotid artery injury
  • 4 risk factors
    • GCS <6
    • Petrous bone fracture
    • LeFort II/III
    • Diffuse axonal injury
  • If any one of above = 41% risk of BCVI
  • If all four = 91% risk of BCVI
• Biffl et al. for blunt vertebral artery injury
  • Only 1 risk factor found = Cervical spine fracture

Blunt cerebrovascular injury

• Diagnosis
  • Diagnostic four-vessel angiography is the gold-standard
  • Unfortunately, even MDCTA has low sensitivity for blunt cerebrovascular injury (<80%)
    • 97% specific however so do not need confirmatory formal angiography
  • USS has a low sensitivity
  • MRI/MRA is not quite as sensitive as four-vessel angiography so should not be used for screening

SCREENING MODALITY

• Four vessel cerebral angiography is gold-standard
• CT
  • Eastman et al.
    • 162 CTA’s followed by 146 confirmatory angiograms
    • 1 false negative (Grade I vertebral artery injury)
    • Sensitivity and specificity of 97.7% and 100% respectively
    • Need 16-slice multidetector CT as older technology not adequate
• CT-A Screening is recommended for all high-force mechanism injuries as studies have shown Denver criteria may miss up to 20% of BCVI in this group

PAEDIATRICS

• Chest trauma (clavicle fracture in particular) and severe head injury (basilar skull fracture, intracranial haemorrhage) were associated with BCVI in children
• Initial screening and treatment should be the same for children as for adults

SURGICAL TREATMENT

• If dense neurological deficit
  • Ligation or repair makes no difference
• If minimal or no symptoms and an accessible carotid lesion
  • Do well with operative intervention
  • Therefore, recommended to repair any more than minor intimal irregularities
• If do not have profound neurological deficit
  • Do better with repair versus ligation

MEDICAL THERAPY

• Antithrombotic medication recommended if not contraindicated
• Reduces rate of neurological sequelae
• Heparin improves mortality (Fabian et al.)
• Heparin appears to prevent cerebrovascular crash (CVC) better than aspirin (Biffl et al.)
  • However, follow-up studies (x3) showed no difference
• Aspirin typically used if heparin or antithrombotic medication contraindicated
• Biffl recommended no heparin loading dose and targeting APTT of 40-50s

Laryngotracheal injuries

• Seen in 2-5% of penetrating neck trauma and 0,5% of blunt neck trauma
• 2-15% mortality rate
• Significant injuries should be detectable on examination
• Hard signs warrant urgent OT
• Soft signs are seen in 18% of penetrating neck injury but only 15% of these will have a laryngotracheal injury diagnosed
• Blunt trauma patients with injuries may have quiescent phase with progressive subclinical airway oedema and haematoma leading to delayed airway obstruction
• Flexible fibreoptic laryngoscopy and MD CTA is warranted for history of significant anterior neck trauma or clinical signs

Laryngotracheal injuries

Pharyngoesophageal injuries

• Seen in 9% of penetrating neck injuries
• Exceedingly rare in blunt neck trauma
  • Any signs and symptoms are far more likely to arise from laryngotracheal injuries
• Typically more subtle and missed on examination alone
• No hard signs exist
• Deaths usually delayed from mediastinitis or sepsis
• Soft signs may exist or trajectory on CT shows close to aerophagic structures
• Prevertebral air is consistent with this also
• Suspect oesophageal injury in sudden accleration or deceleration injuries where neck was extended
  • Oesophagus becomes forced against the spine

Pharyngoesophageal injuries

• Diagnosis
  • Intraoperative endoscopy if hard signs in penetrating trauma and going to OT anyway
  • Direct oesophagoscopy and/or swallow studies if symptomatic without hard signs
  • Oesophagoscopy is more sensitive with benefit of quantifying size and extent of injury
  • Combined have 100% sensitivity
  • If asymptomatic, MDCT
    • If negative, can observe or if high suspicion exists, perform direct oesophagoscopy or swallow studies with water-soluble agent
• Treatment
  • IV antibiotics, nutrition via parenteral or NG route
  • Small pharyngeal perforations can be managed medically
  • Pharyngeal perforations >2cm and all oesophageal perforations require surgical repair

Strangulation

• Mechanisms include hanging, postural strangulation, ligature strangulation and manual strangulation
• 10% of violent deaths due to this in US
• In all forms, death is due to cerebral anoxia and ischaemia
  • Obstruction of cerebral venous return rather than acute airway compromise is postulated to be the most common mechanism
• Clinical features
  • Venous obstruction with cerebral vascular congestion, oedema and unconsciousness with subsequent loss of muscle tone and carotid obstruction with cerebral anoxia
  • Airway obstruction and carotid body reflex-mediated cardiac dysrhythmia are minor mechanisms of death
  • Other injuries include laryngotracheal fractures, C-spine fractures, pharyngeal lacerations and carotid artery injuries
  • Hyoid bone fractures found in the minority
  • Mainly only judicial hangings result in C-spine or cord injuries
  • Carotid artery dissection is rare but should be suspected if lateralising neurological examination or bruising/tenderness over the carotid artery

Strangulation

• Clinical features
  • Petechiae and neck contusions
    • Palatine petechiae often missed
  • Self-induced scratch marks as patients grab at their neck to release pressure
  • Other signs of attempted escape/DV
  • 50% of victims have no signs of neck trauma
  • 2/3 are asymptomatic
  • Extensive laryngeal injury can have minimal physical signs
  • Symptoms include neck pain, voice changes, dysphagia and breathing problems
    • Can all herald acute airway compromise
  • If in cardiac arrest = dismal prognosis
  • Recovery of patients with neurological deficits is unpredictable
  • Most in-hospital, post-strangulation deaths occur due to laryngeal or pulmonary oedema or cerebral anoxia

Strangulation

• Most difficult part is knowing what to do with walking and talking patients
• May be intoxicated and be disregarded
• A small subset of seemingly asymptomatic patients may die after delayed cerebral or pulmonary oedema
• Decision to perform CT/CTA head/neck is a difficult one and there are no clear cut guidelines
• Evidence suggests those that receive imaging are more likely to result in a conviction
• Many case reports of patients without focal neurology suffering cervical dissections
• Diagnosis
  • CXR – Pulmonary oedema, larynx or hyoid fractures, tracheal deviation due to oedema or haematoma
  • CT – Intramuscular haemorrahge/oedema, swelling of platysma, subcutaneous bleeding or haemorrhagic lymph nodes
  • MD CTA or four-vessel angiography – Carotid artery imaging should be performed on patients with neurological deficits discordant with brain CT findings
  • Laryngobronschopy – Dyspnoea, dysphonia, aphonia, odynophagia

Strangulation

• Treatment
  • Intubation – Unconscious, progressive odynophagia/hoarseness/neurological signs/dyspnoea
  • Pulmonary oedema may benefit from PEEP
  • Cerebral oedema may require intubation, measures to limit ICP and seizure prophylaxis
  • Observe asymptomatic patients for delayed respiratory or neurological dysfunction
  • Social work and MH assessment if indicated
  • Only 5% of strangled DV victims seek medical attention within 2 days
    • High risk of death and harm from same abuser
  • Evaluate suicide attempts for other means e.g. paracetamol level, wrist lacerations, self-stabbing
• Documentation
  • This is key for conviction of offenders
  • Detail specific mechanisms e.g. cord, strangulation, suffocation, consenting/not and all relevant examination features

Hanging

• Non-judicial hanging has potential to cause complex array of injuries to hypopharynx, arteries and cervical spine
• Highly variable results in type and severity depending on duration of hanging and whether complete or incomplete suspension from the ground
• Schuberg et al. (2019) AJEM
  • 78 patient retrospective review of protocolized CT head non-contrast and CT angiogram head/neck for all hanging presentations
  • Excluded strangulations
  • 65% found hanging at scene
  • 87% GCS 15
  • >75% had advanced imaging of head and neck of some description
  • No significant pathology identified
  • Arrival GCS <8 = 67% mortality
  • Arrival GCS >8 = 0% mortality

Hanging

• Selective criteria recommended (in keeping with Subramaniam et al.)
  • GCS <15
  • Cervical spine tenderness
  • Symptoms of neurological, vascular or airway injury
  • Abnormal vital signs

Last Updated on June 8, 2021 by Andrew Crofton