Penetrating Neck Trauma

C McCrossin, R1

Objectives• Anatomy

• Clinical Features

• Diagnosis

• Management

• Disposition

Not Covered:• C-Spine injuries

• Blunt neck trauma

Definition• Penetrating neck trauma is any injury

that penetrates through the platysma

Zones of the Neck

Neck Zones-The Basics• Zone II is the most exposed and accessible to

direct surgical visualization and easier vascular control

• Zones I and III have structures that lie deeper making diagnosis and management of vascular injury more difficult.

• Important to note which zone contains the injury and if the platysma is penetrated (without deep probing)

Neck Zone I• Proximal carotid artery• Vertebral artery• Subclavian artery• Major vessels of the upper mediastinum• Apices of the lungs• Esophagus• Trachea• Thyroid• Thoracic duct• Spinal cord

Neck Zone II• Carotid artery

• Vertebral artery

• Larynx

• Trachea

• Jugular vein

• Recurrent laryngeal nerve

• Spinal cord

Neck Zone III• Distal carotid artery

• Vertebral artery

• Distal jugular vein

• Salivary and parotid glands

• Cranial nerves IX-XII

• Spinal cord

Pretracheal layer of the deep cervical fascia inserts on the anterior pericardium putting patients with penetrating aerodigestive injuries at risk for mediastinitis

Diagnosis

Clinical Features• Rarely do you have an isolated injury to

the neck (polytrauma more common)

• Anatomical injuries to look for:– Vascular– Laryngotracheal– Esophageal– Neurological

“Soft” Signs• Hemoptysis/hematemesis• Oropharyngeal blood• Dyspea• Dysphonia/dysphagia• Subcutaneous air• Chest tube air leak• Non-expanding hematoma• Focal neurologic deficits

Vascular Injuries (Common Exam Question)

• “Hard” Signs of Vascular injury:– Shock– Airway obstruction– Inspection

• Pulsatile bleeding• Expanding hematoma

– Palpation• Thrill• Absent radial pulse

– Auscultation• Bruit

– Ischemia• Cerebral (stroke symptoms) • Upper limb (pulse deficit)

Vascular Injuries• Morbidity and Mortality:

– Exsanguination– Hematoma and airway compromise– Direct vascular injury and subsequent occlusion– Bullet embolization– Air embolism

• Late complications:– Traumatic aneurysm– AV fistula formation (may present a few weeks

after trauma)

Laryngotracheal injuries• Signs of Tracheal Injury

– Subcutaneous emphysema (most common)

– Respiratory distress– Hemoptysis– Hoarseness– Air bubbling from wound

(hard sign)– Deformities of landmarks– Deformity of neck

landmarks– Mediastinal air– Stridor

Esophageal Injuries• Clinical Features

– Dysphagia– Oral bleeding/blood in NG– Subcutaneous emphysema– Resistance to ROM of neck

• May be asymptomatic

Esophageal Injuries• Least common injury to occur

• Most common injury to miss

• Mortality secondary to mediastinitis

Neurological Injuries• Spinal cord• Cranial Nerve• Peripheral Nerve• CNS• Be wary of associated arterial injuries with

neurological deficits because most nerves are located close to large arteries

Cranial Nerves

1.Glossopharyngeal

2.Hypoglossal

3.Vagus

4.Sympathetic Trunk

5.Phrenic Nerve

Diagnosis• Physical Exam

• Vitals• Evaluate patients for “hard” and “soft” signs of injury

• Radiology• Mandatory CXR and Neck views• CT Angio• Angio• U/S• Esophagography

• Scopes• Esophagoscopy (rigid/flexible)• Laryngoscopy• Bronchoscopy

Physical Exam• Will miss 1/4 vascular injuries with

physical exam alone (all neck zones)

• Better at ruling out airway injuries

• Most commonly miss esophageal injuries

X-Ray• CXR to rule out pneumothorax,

chylothorax, hemothorax

• Lateral neck films• Can demonstrate retropharyngeal air, tracheal

deviation• Cervical spinal injuries

Angiography• Gold standard for evaluating possible

vascular injuries

• Invasive

• Potentially therapeutic

MR-Angiography• Used for assessment of vascular

injuries

• Not good for bony structures

• Limited use in trauma patient b/c of need for proper monitoring and MR-incompatible equipment

Helical CT Angiography• Highly sensitive and specific for vascular

injuries (NPV 98%, PPV 100%)» Trauma Reports Nov/Dec 2006

• Cannot treat the vascular injury and patients may still require angiography

• Difficult to assess the subclavians

• Widely used in neck trauma

Helical CT• CT alone is a highly sensitive diagnostic

tool

• Negative CT does not rule out aerodigestive injuries

Helical CT• Inaba et al 2006 evaluated the use of CT in

penetrating neck trauma in all zones• 91 patients (34 GSW, 57 Stab)• Compared CT against a gold standard of

surgery/followup/all other imaging• CT was 100% sensitive, 94% specific• No injuries were missed with 85% follow-up

Endoscopy• Flexible endoscopy is primary means to

investigate laryngotracheal trauma (average FN rate of 20%)

• More difficult to evaluate esophagus and pharynx than the laryngotracheal system

• May require contrast swallow imaging to detect esophageal injuries in the cervical region (sensitivity reportedly as low as 60%)

• Rigid endoscopy is more sensitive but technically more difficult and not always available

Color Flow Doppler• Non invasive• Highly operator dependent• May not be available at night or on

weekend• Lots of artifacts (ie Bone)• Difficult to examine smaller vessels• Only real use is as an alternative in

stable patients with zone II injuries

Summary Of InvestigationsDIGESTIVE VASCULAR LARYNGOTRACHEAL

Physical Exam Physical Exam

Angio (gold standard)

Physical Exam

Lateral neck xray/CXR

Lateral Neck xray CT Angio sensitive and specific

Endoscopy

CT cannot rule out

Esophagoscopy

CXR, Lateral Neck

Color Flow US

Laryngoscopy

Bronchoscopy

Contrast Swallow

Management: The Debate• Long historical debate over mandatory exploration

and selective management• Prior to WWII expectantly watching stable patients

resulted in a mortality rate of up to 35%• Mandatory exploration reduced mortality rates to 6%• Mandatory exploration results in a 50-60% negative

exploration rate• However there is little morbidity or mortality with a

negative surgical neck exploration• Need to strike a balance that minimizes both mortality

rates and the rate of negative surgical explorations

Management• Airway

– RSI is considered safe

• Breathing– Beware of pneumo– Hemothorax/

chylothorax also possible

• Circulation– Don’t clamp– Direct pressure to control

bleeding

• Exposure– Look for other injuries– Do not probe neck injury

• Disability– C-spine precautions if

indicated

Quick word on airway• RSI is safe• Neck is a tight

compartmentalized space which may appear ok externally but significant airway compromise can be secondary to edema or hematoma

Management Approach (Common Exam Question)

No further work-up

Platysma Not PenetratedStable

Immediate OR

Platysma Penetrated-Unstable

-Expanding hematoma-Severe active/pulsatile bleeding

Zone I or IIITriple Scope + CT Angio

or OR exploration

Zone IIIf no physical findings -> No Tests

If any soft findings then triple scope plus CT Angioor Exploration in OR

Selective Management-based on zone

-hard and soft signs

Platysma PenetratedStable

Neck Trauma

Zone I• Managed selectively because of difficulty

obtaining intra-operative exposure• Investigations

– Arteriogram to exclude great vessel injury– Bronchoscopy to identify laryngotracheal injuries– Combination of esophagography and

esophagoscopy to evaluate for potential esophageal injuries

Zone I (cont.)• Is routine arteriography mandatory for

penetrating injuries of zone 1?– 138 pts, 10 year retrospective study– Results demonstrated CXR and PE have a

NPP of 100% at ruling out arterial injury– Conclude that routine arteriography may

not be necessary » Eddy et al 2000

Zone II• Controversial Region in stable patients

• Trend is towards selective management vs mandatory surgery

• Easiest zone to both diagnose injury and best for gaining adequate intraoperative exposure

How Good is P/E at Detecting Zone II Vascular Injury?

• Prospective use of physical exam (P/E) in 145 patients with zone II injuries

• F/U included repeated P/E over 23 hours plus 2 week post injury F/U

• Use of “hard signs” to decide on surgery:

» Active bleeding, expanding hematoma, thrill over the wound, pulse deficit, central neuro deficit

Role of Physical Exam alone in Zone II Vascular Injuries

Use of Physical Exam in Penetrating Zone II Injuries

Immediate OR3 False Positives/

2 of 3 had non vascinj requiring repair

28 (90%)Major Arterial

or venous injuryrequiring repair

31 (21%) Hard Signs

3 Showed arterialabnormalities

2 abn were benign1 small lac in carotid identified

23 underwent angio5 b/c of prox to vert art

18 b/c injury in other zone

91 observedwith no consequence

114 (79%)No Hard Signs

145 PatientsType Title Here

Zone II Vascular Injuries (cont.)

• Authors concluded that physical exam alone can be used to exclude significant vascular injuries in zone II with a FN rate comparable to angiography.

Role of CT in Zone II Injuries• Prospective; 42 patients with Zone II injuries• All pts had CT, esophagography, then OR• 2 esophageal injuries (out of 4) missed by

P/E, CT and esophagography• All patients with tracheal and carotid injuries

were identified by CT alone• Conclusions: CT has little impact on

diagnosis and management » Gonzalez et al 2003

Zone II (cont.)• The debate over mandatory OR vs selective

management of zone II injuries is ongoing however most centers have adopted a selective approach

• Physical exam alone may be sufficient to exclude significant vascular injury

• CT may be beneficial at identifying bullet trajectory

Zone III Vascular Injuries• Require studies of the cerebral

circulation, upper airway, and esophagus

• All symptomatic patients with zone III injuries require diagnostic evaluation of both esophagus and arteries

Zone III• Absence of hard signs reliably excludes

surgically significant vascular injuries in zone III suggesting angiography is not necessary

• Hard signs in a stable patient should mandate angiography because these vascular injuries may be amenable to endovascular therapy

» Ferguson et al 2005

Laryngotracheal Injuries• 10% of penetrating neck injuries include

a laryngotracheal injury

• Rarely are these injuries occult

• Mandatory laryngoscopy with any of the previous mentioned signs

• Bronchoscopy for symptomatic injuries in zones II and III

Esophageal Injury• Found in ~ 7% of penetrating neck trauma• Combination of physical exam, endoscopy,

and esophagography can reliably diagnose all significant injuries

» Demetriades et al 2001

• Most of these injuries require EARLY operation to decrease morbidity and mortality secondary to mediastinitis

Neurological Injuries• 10% of asymptomatic patients with gunshot

wounds to the trunk had associated spinal injury

• Actual prevalence of spinal cord and neurological injury is controversial but bad outcome if overlooked

• Approach varies depending on signs/symptoms and mechanism of injury

Does Mech of Injury matter?

Harry Whittington

Why is his pic in my presentation?

Shot in the neck by this evil man:

Great example of penetrating neck trauma reaching all three anatomical

zones!

Ballistics• Tissue penetration and trajectory dependent

upon many different factors (muzzle velocity, bullet design, etc) therefore difficult to predict internal injury and imaging warranted (angio, CT angio)

• Gun-shot wounds to the neck are not absolute indications for exploration

» Demetriades et al 1996

• CT is very useful at tracking path of bullet

What should we be doing in Calgary?

• Zone I & III injuries: If stable and regardless if symptomatic or asymptomatic then triple scope (esophagoscopy/laryngoscopy/bronchoscopy + CT angio)

• Zone II injuries: If stable and asymptomatic then observe for 24 hours (no investigations), if any soft signs then triple scope plus CT angio or OR

Practical Tips• CXR to r/o Pneumo• IV’s and Central lines

on opposite side of injury

• Trendelenberg to decrease air embolism

• Ancef to decrease risk of infection (esp mediastinitis)

• Consult early

The “Do Nots”• Never clamp vessels (direct pressure)

• Don’t poke/probe (may release hematoma)

• Don’t remove impaled objects

• Don’t place an NG

SUMMARY• Does the injury penetrate the platysma?• Management based on stable/unstable,

zones, and presence of “hard” and “soft” signs

• RSI is considered safe• Evidence suggests that physical exam is a

powerful tool which can rule in and rule out significant vascular injury

• Imaging required in high velocity penetrating trauma

Summary (Cont.)• Angio is gold standard for vascular

injuries, CT angio also highly sens/spec

• Esophageal injuries most commonly missed =>risk of mediastinitis (deep fascia anatomy)

The End