1. Penetrating Neck Trauma
C McCrossin, R1

2. Objectives Anatomy Clinical Features Diagnosis Management Disposition
Anatomy: How injuries are classified based on anatomy, what structures are at risk of injury
Clinical features: What signs/symptoms we might see that will affect how we manage the patient
Diagnosis: What investigative strategies we have at our disposal to rule in/rule out particular injuries
Management
Disposition

3. Not Covered:
C-Spine injuries
Blunt neck trauma

5. Definition
Penetrating neck trauma is any injury that penetrates through the platysma

6. Zones of the Neck Zone 1: Sternal notch to the cricoid cartilage
Zone 2: Region between the level of the cricoid and the angle of the mandible
Zone 3: Extends from the angle of the mandible to the base of the skull

7. 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)
1. Zone II is easiest zone to gain access to in OR
2. Zone I injuries may also involve mediastinal structures
3. Two of the most important things to note when assessing penetrating neck injury is which zone contains the injury and whether or not the platysma is penetrated because this will direct how you will be managing the patient.

8. 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
What structures will you be worried about when assessing a zone 1 neck injury (define zone 1)

9. Neck Zone II Carotid artery Vertebral artery Larynx Trachea
Jugular vein
Recurrent laryngeal nerve
Spinal cord

10. Neck Zone III Distal carotid artery Vertebral artery
Distal jugular vein
Salivary and parotid glands
Cranial nerves IX-XII
Spinal cord

11. Pretracheal layer of the deep cervical fascia inserts on the anterior pericardium putting patients with penetrating aerodigestive injuries at risk for mediastinitis
Fascial planes: Superficial and Deep Fascia
Deep Cervical Fascia is divided into three parts: 1. Investing layer (surrounds the neck and splits to cover the SCM and Trapezius), 2. Pretracheal layer (adheres to cricoid and thyroid cartilage and travels caudally behind the sternum to insert on the anterior pericardium, 3. Prevertebral layer (envelops the cervical prevertebral muscles and extends to form the axillary sheath which covers the subclavian artery.
Deep layers may help contain a hematoma or provide a pathway of infection into the mediastinum.

12. Diagnosis

13. Clinical Features
Rarely do you have an isolated injury to the neck (polytrauma more common)
Anatomical injuries to look for:
Vascular
Laryngotracheal
Esophageal
Neurological

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

15. 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)
The so called “hard signs” of penetrating neck trauma seem to vary depending on what text you read
***Ischemia in upper limb: Pulselessness, pallor, paralysis, poikilothermia, pain.
***Presence of a nerve injury in the upper limb should also make you think of a potential vascular injury because nerves tend to travel close to the arterial circulation.
** Also shock not responding to fluids

16. Vascular Injuries Morbidity and Mortality: Late complications:
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)
A lot of the morbidity and mortality is related to vascular injuries
2.Reports in the literature of hematomas causing airway compromise

17. 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
*Only “hard” sign of laryngotracheal trauma is air leaking through wound, often more pronounced during coughing. Other signs suggestive of but not diagnostic include: subcutaneous emphysema, hemoptysis, and hoarseness. Dyspnea alone without associated subcutaneous emphysema may be due to laryngotracheal trauma or an external hematoma compressing the airway.
**Bolded are the most common signs
***From Demetriades 2001

18. Esophageal Injuries Clinical Features May be asymptomatic Dysphagia
Oral bleeding/blood in NG
Subcutaneous emphysema
Resistance to ROM of neck
May be asymptomatic

19. Esophageal Injuries Least common injury to occur
Most common injury to miss
Mortality secondary to mediastinitis
Least common injury because of the esophagus’s relatively protected location. Most of these injuries are associated with tracheal injuries as well because of proximity.
Most common injury to miss and there is a correlation between delay of diagnosis and mortality so important injury to rule out.

20. 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
Approx 10% of patients with penetrating neck trauma will have an associated spinal cord or brachial plexus injury. In EMR they comment on a report that showed that 10% of asymptomatic patients with gunshot wounds to the trunk, head, or neck had spinal injuries.
Case report in EMJ 2006 of an isolated horner’s syndrome occuring from an intraoral gunshot wound (Dec 2006)

21. Cranial Nerves 1.Glossopharyngeal 2.Hypoglossal 3.Vagus
4.Sympathetic Trunk
5.Phrenic Nerve
To keep the anatomy in mind
CN’s XI, X, XII (symptoms: Dysphasia, tongue fasciculations, autonomic instability)
Phrenic nerve and sympathetic trunk (decreased A/E ? Mimic pneumo, horner’s - mimic stroke)
How close nerves run with arteries

22. Diagnosis Physical Exam Radiology Scopes 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
World J Surg 18:

23. 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
1/4 of vascular injuries missed according to EMR
Will have more to say on physical exam when we get to the individual neck zones and management

24. X-Ray CXR to rule out pneumothorax, chylothorax, hemothorax
Lateral neck films
Can demonstrate retropharyngeal air, tracheal deviation
Cervical spinal injuries

25. Angiography Gold standard for evaluating possible vascular injuries
Invasive
Potentially therapeutic
Risks of angiography

26. 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
Not really used

27. 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

28. Helical CT CT alone is a highly sensitive diagnostic tool
Negative CT does not rule out aerodigestive injuries
Generally accepted that a negative CT does not rule out aerodigestive injuries because most studies demonstrating its high sensitivity have involved low patient numbers

29. 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
*I included this study in my presentation because it is one of the larger studies looking at penetrating neck trauma and investigative modalities, it is recent (not in rosen’s or EMR)
**11 patients were discharged home at 6-24 hours after a negative CT and not available for follow up

30. 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
*Cervical esophagus is very difficult to evaluate (lower sensitivity with flexible endoscopy compared to other esophageal areas)
**Choice of study will depend upon specific center and experiene however most centers use a combination of esophagography and esophagoscopy for diagnosis
****mixed reports on the sensitivity of swallow studies an its ability to pick up significant injuries.
Statistics are from Demetriades 2001.

31. 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
Color flow doppler can be used to look at blood flow in the cervical vasculature. Lots of disadvantages but it is non invasive. Angio and CT angio are better.
One study that speaks in favor of using instead of CT in zone II injuries (really its only potential use)

32. Summary Of Investigations
DIGESTIVE
VASCULAR
LARYNGOTRACHEAL
Physical Exam
Angio (gold standard)
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
Difference between endoscopy and esophagoscopy

33. 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
The challenge has been finding the balance between minimizing mortality rates and minimizing the rate of negative surgical explorations. The mortality rate of 35% that I quoted you is primarily from military statistics which represented injuries from high velocity objects which might not be representative of the MVC / stabbing patients we would see in emerg with penetrating neck trauma.

34. Management Airway Breathing Circulation RSI is considered safe
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
No formal consensus on how the airway should be managed in these patients however RSI is considered safe.
Disability: Remember the incidence of spinal trauma in penetrating neck trauma is debatable and often initially occult.

35. 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
Case reports in the literature of patients with benign looking necks eventually undergoing cric because expanding hematomas have distorted the airway enough to make direct laryngoscopy impossible

36. Management Approach (Common Exam Question)
Patients fall into three general categories
Mandatory exploration of all significant penetrating neck trauma to avoid missing any important injuries yields a range of 30-90% of negative explorations.
Zone I or III may first go to angio depending on CT angio findings because of difficulty with OR exposure.

37. 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
1. Many zone I injuries will have associated pneumo or hemothorax.
2. Physical exam and Surgical exposure is difficult in these patients
3. Angio has traditionally been mandatory in patients with zone one injury however there is some debate around this issue
4. Zone associated with the greatest mortality when penetrated

38. 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
One study published in 2000 in the Journal of Trauma suggest that routine arteriography may not be needed in patients with normal PE and CXR. The study looked at 138 patients of which 38 had normal physical exam and CXR and none had an arterial injury. Couldn’t find any studies that have followed up on this one and so far this study certainly hasn’t changed clinical practice.

39. 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

40. 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
So how good is our physical exam at evaluating for serious arterial injury in zone II injuries?
Only 42% of patients followed up at 2 weeks.
Sekharan et al. J Vasc Surg 2000: 32(3):483-9

41. Role of Physical Exam alone in Zone II Vascular Injuries
J Vasc Surg 2000; 32(3):483-9

42. 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.
Penetrating trauma can cause occult arterial injuries that show no hard or soft signs of vascular injury in approx 10-15% of cases. These types of injuries include smooth narrowings, intimal irregularities, and small pseudoaneurysms and AV fistulas. If angio is not obtained routinely, these minimal injuries will be missed. Data regarding these injuries in the extremities amounts to Approx 1-2% of these types of injuries deteriorating into significant lesions requiring surgery (AV fistulas are the most likely to cause problems). However, these injuries normally occur within several weeks after the injury and can usually be repaired with no additional morbidity. Data regarding these sorts of injuries in the neck is not as plentiful. However multiple studies involving 1200 patients suggests that physical exam is able to diagnose significant vascular injury in over 99% of patients with zone II penetrating injuries. (J Vasc Surg 2000: 32(3):483-9)

43. 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
Primarily stab victims (36 pts, 86%), 6 gunshot (14%). Esophageal injuries that were missed were stab victims. All vascular injuries were diagnosed by physical exam alone and went directly to the OR. Esophageal injuries most likely of no clinical significance.
Authors conclude that CT has a limited role in assessing zone II injuries, however it is difficult to conclude from demographics that CT would play no role in identifying trajectory of a bullet (ie would prob do a CT in patients with bullet wounds)

44. 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

45. 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 injuries are much more difficult to explore surgically and stable patients with platysma penetration automatically undergo investigation to identify occult injuries.

46. 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
15 year retrospective study of 73 patients with zone III injuries (35 gun shot, 32 stab, 5 shotgun)
52 patients had no hard signs - 24 underwent angio - 18 angios were neg, rest had injuries not requiring intervention. Remaining patients were observed with no consequence prior to D/C.

47. 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

48. 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
*Demetriades et al World J Surg 2001:25: PE and symptoms can rule out
**Gonzales J Trauma 2003: 54: esophageal injuries missed by physical exam and CT and esophagography--> Small injuries missed by esophagography and CT are typically very small and may not be clinically significant (ie they would otherwise heal spontaneously)
***Some esophageal injuries have been reported to have been managed non operatively with only antibiotics, but anything below the arytenoids or if large then operating room plus antibiotics.

49. 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
Ref 21 in EMR - Klein et al, j trauma, 2005;58:833
Look at Connell’s study- ref 22.

50. Does Mech of Injury matter?
Harry Whittington
Why is his pic in my presentation?

51. Shot in the neck by this evil man:

52. Great example of penetrating neck trauma reaching all three anatomical zones!

53. 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
*CT is useful at tracking path of bullet. If path is away from the esophagus and trachea and there are no signs of aerodigestive injury then scoping is not necessary (Demetriades 2001)

54. 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

55. 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
Thanks to Rob Hall

56. 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

57. 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

58. 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)

59. The End