Penetrating injuries to the neck is a great summary of how to assess and manage neck wounds from lacerations to the airway to gunshot wounds. The talk covers relevant anatomy, the zones of the neck and how to investigate vascular, tracheal and oesophageal injuries. A comprehensive understanding of the relevat anatomy is essential to recognising associated injury patterns. The improvements in the accuracy of helical CTA scans has meant that the delineation of the zones of the neck has become less relevant to the further investigation and management of pemetrating neck wounds. Oesphageal injuries remain difficult to detect and require a high level of clinical suspicion to identify these.
21. Key points
âą Exan
âą Leading cause of immediate death is exsanguination
âą Esophageal injuries represents the most frequently
missed injury and may be leading cause of delayed
death
âą Compound difficulties in evaluation & Mx is the
complicated anatomy - dense concentration of vital
structures in a small space
âą Ongoing debate : mandatory vs selective exploration
Hinweis der Redaktion
Clint Malarchuk â1989
Goaelie for Sabre â Ice hockey team from Buffalo New York
It is a topic where anatomy is criticalâŠâŠ.anatomy trumps pathophysiology for once, so as a surgeon, I really lke this topic.
It Makes up 10-15% of trauma pts so its important to have a good understanding of the mx
While mx of the unstable pt is exciting but pretty straight forward, the management of the stable pt remains a source of debate.
Historically, penetrating neck injuries is quite an interesting topic.
Largely the domain of the military surgeons
Initially mortality was huge â higher than 30%. During the first world war, there wasnât too much that could be done.
WW2 - surgical advances meant that all patients with neck injuries were explored.. As injuries to imporant sturctures began to be pciked up earlier and treated, mortality began to drop.
So by the time of the korean war and vietnam way, âŠâŠ.
With mandatory exploration of everyone with a PNI as well as mobile army surgical hospitals, the mortality rate was as low as 3%
More recentlyâŠâŠ mortality has started to rise again⊠âŠbut largely due to wartime advances. Things such as high velocity rifles, improvised explosive devicesâŠâŠ
Because when it comes to the damage that is caused in these inuries, it all comes down to kinetic energy.
And with KE, velocity is much much more important than the mass or size of the projectile.
With weapons , you talk about the muzzle velocities âŠhand guns for intstance have velocities 200-600m/s.
But once you start getting speeds over 600m/s, as you do with high powered rifles, you get this effect know as cavitiationâŠâŠ.
The problem with the neck is the anatomy â complex way in which a large number of essential structures are crammed into a small area.
Problem with PNI is that there is a lot of vital structures, all packed into a small area.
Just wanted to take a brief moment to highlight some of the more important anatomical structuresâŠ.
If you know your anatomy and where exactly some of these more critical structures are, it helps in the management of any PNI
Vascular structures â
Jugular viens(external) in my experience is most common injury. Often easily seen on people as it is one of the most lateral structures. If you draw a line from the angle of the mandible to mid clavicle, that is its pathway, passing over the SCM obliquely
Internal jugular along with the carotids lie underneath the SCM which protects it, less so in the upper neck. Carotid is obviously deeper and slightly more anterior to Jug. To outline the pathway of these vessles, you take a line from just in front of the ear, to the medial end of the clavicle.
The bifurcation is around the same level as the thyroid cartilate.
Vertebral arteries, deeper and more posterior
Brachiocephalic/subclavial vessles become important lower neck injuries as the rise and arch over in the root of the neck.
Laryngeal cartilages midline and susceptiable to any anterior injury
Mangament of airway
Eosphagus really starts around the level of your cricoid and the pharynx is everything above that.
Nervous structures â not just cranial nerves, also branchial plexus, sympathetic chain and obviously spinal cord (injury to SC is relatively rare in PNI)
Thing to remember is that these neural sturctures are often in close proximity to vascular structures so neuropathies can be a clue to possible vascualr injuriesâŠâŠ
cranial nerves CN7,9 if higher in the neck, vagus, accessory and hypoglossal
can be injured directly in the neck but also at the jugular foramen where 9,10 and 11 all come down with the internal jug.
sympathetic trunk that travels within the carotid sheath â horners
brachial plexus in lower neck between anterior and middle scalene so important to examine the hand
spinal cord injury uncommon
Iâd be interested in any comments at the end about this - utiltiy of neck collars recently in the news and I would have to say that in these injuries where the incidence is so low, and the ability to be able to assess both initially and over tie is imporatnat,, that neck collars shouldnât be used unless there are definate concerns.
Vascular structures, neural structures, airway, digestive tractâŠâŠ.all intertwined in a complex manner within a small area. Overlying all of these structures, and protecting them to some degree is the platysma muscle.
The essence of any PNI is that it penetrates this muscle.
Attaches to fascia of pec and deltoid muscles, crosses clavicles, some fibres attaching superiorly to mandible and others interlacing with skin and superficial muscles of the face.
So you can describe PNI by location, often using SCM as reference as this is boundary for anterior and posterior neck trianglesâŠâŠ.or you can talk about the zones of the neck.
PNI categorised by zones â carries implications for management and prognosis
Zone one
From clavicles to cricoid cartilage
Includes
Arch of aorta, innominate, subclavian, vertebral
Lung apices
Thoracic duct on the left
Brachial plexus
This is the zone with the highest mortality â 12%
Dangerous due to proximaty to large thoracic vessels and the lungs
Osseous shield which protects it on one hand but also makes surgical access difficult on the other
Pt with injuries in this zone you would consider doing angiogram. Injuries are not only hard to see, but also hard to access.
Zone 2
mid neck - Most common zone of injury (up to 75%) of injuries
Cricoid cartilage to angle of mandible
Structures of note in this zone are the
carotids, vugular veins
Cranial nerves
Sympathetic chain
Larynx and pharynx
No osseous shield
Surgical access is much better and obtaining distal and proximal control of bleeders is possible
This is the zone where Elective v mandatory exploration becomes controversial
Historically, around 90âs people started realising that mandatory explorations was not nesessary
Large number of negative explorations
Not cost effective
Imaging advances such as helical CT becoming widelly available and commonlace
People began advocating conservative mx but those that apposed it agued that not all injuries could be picked up with just physical examination.
Literature supports both argumentsâŠ..
Zone 3
Angle of mandible up to base of skull
Vascular structures â ext/int carotids, jugular, vertebral and prevertebral plexus
Oral cavity and pharynx
Neural structures â consider facial nerve trunk
Vascular injuries in this area are much more challenging to be repaired surgically
Proximity to skull base and mandible offering osseous shield
Mandatory exploration is not recommended and like zone 1, angiogram often recommended.
So how does this help usâŠâŠits all very well to be able to describe the injuries but does it really matter.
As an ENT surgeon, Iâm not going to talk to a critical care crowd about how to go through the management of these ptsâŠ.but rather look at each zone and the implications it has on management.
The only two things that Iâll say about prehospital treatment, and Iâd be interested if anyone has any comments on this is
?? collars â spinal injury very unlikely and immobilisation often done at expense of easy, accurate and continued examination
air embolismâŠ..often mentioned but Iâd say that if a pt has an airway injury, letting them find the best way position to help maintain their airway is best.
Prehospital pearls
No collars â spinal injury very unlikely and immobilisation often done at expense of an accurate examination.
Bag mask ventilation can be problematic and may lead to surgical emphysema if airway injury and significant anatomical distortion
Bubbling or sucking neck wounds â beware air embolism
?????Think tension pneumothorax if arresting??????
Attacked by fighting roosterâŠâŠ.
Initially assessed; puncture wounds to face & neck; D/Câd
RTER 24 hr later w/ fever, neck swelling, & respiratory distress
Neck: crepitus; inflammation; induration
CXR: pneumomediastinum
Endoscopic EUA: 0.5 cm perforation of lateral wall of pharynx
Neck explored through lateral incision ï pus drained
NG feeds ï N contrast study POD#10
D/C HD#14 on N diet