Transmediastinal
Penetrating Injuries
Tanya L. Zakrison, MD, FRCSC, FACS, MPH
Ryder Trauma Center
University of Miami Miller School of Medicine
Florida, USA
Sept. 20, 2014
Clinical Case –



24 male patient, found down in a ‘dangerous
part’ of São Paulo
EMS / Paramedics arrive
He is breathing, has right-sided
subcutaneous emphysema, blood pressure
90/50 mmHg and one obvious gun-shot
wound on his chest


5th intercostal space, right side
No other injury
What is next?
Paramedics

Pre-hospital care

most important is prompt transportation to a trauma
center






SCOOP AND RUN
A - ETT – careful for tracheobronchial injuries
B - Needle decompression for presumed (tension)
pneumothorax
Circulation – IV access, hypotensive resuscitation?
D - Cervical or spinal cord injury – possible
Exposure

Difficult to diagnose in the field

Unless one gun shot was heard, and 2 wounds on chest
Nurses


ATLS protocol in the trauma bay
Work as a team, excellent communication



Repeat the ABCDEs
Verify ETT placement
Help the surgeons place a tube thoracostomy on
decompressed side


Verify that the IV sites are in place, 20 cc/kg crystalloid



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Contralateral side too if still hypotensive
Blood (massive transfusion protocol)
ED thoracotomy?
FAST & CXR
Do we need to operate or not?
ICU Care

Look for occult injuries





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Missed after surgery
Missed on CT scan
Bronchoscopy
Endoscopy
Echocardiography
Other tests
Definitions

Mediastinum: (Dorland’s Medical Dictionary)
A median septum or partition
The mass of tissues and organs separating the two lungs,
between the sternum in front and vertebral column behind
1.
2.

Transmediastinal Penetrating Injury / GSW
(Richardson et al. 1981)
Opposite hemithoraces have:





Missle entry & exit wounds
Missle entry & retained missile
Traverse Mediastinal Gun Shot Wound
Transverse Mediastinal Gun Shot Wound

A transmediastinal penetrating injury does
not necessarily mean a penetrating injury to
the mediastinum

Do we always have to operate?
Anatomy: Mediastinum “Interpleural Space”
Anatomy: Mediastinum “Interpleural Space”
Mediastinal Contents

Superior:


Anterior:


It contains a quantity of loose areolar tissue, some
lymphatic vessels which ascend from the convex
surface of the liver, two or three anterior mediastinal
lymph glands, and the small mediastinal branches of the
internal mammary artery.
Middle:


the aortic arch; the innominate artery and the thoracic
portions of the left common carotid and the left
subclavian arteries; the innominate veins and the upper
half of the superior vena cava; the left highest intercostal
vein; the vagus, cardiac, phrenic, and left recurrent
nerves; the trachea, esophagus, and thoracic duct; the
remains of the thymus, and some lymph glands.
It contains the heart enclosed in the pericardium, the
ascending aorta, the lower half of the superior vena
cava with the azygos vein opening into it, the bifurcation
of the trachea and the two bronchi, the pulmonary artery
dividing into its two branches, the right and left
pulmonary veins, the phrenic nerves, and some
bronchial lymph glands.
Posterior:

It contains the thoracic part of the descending aorta, the
azygos and the two hemiazygos veins, the vagus and
splanchnic nerves, the esophagus, the thoracic duct,
and some lymph glands.
Anatomy: Mediastinum “Interpleural Space”
Mediastinal Contents

Superior:


Anterior:


the aortic arch; the innominate artery and the thoracic
portions of the left common carotid and the left
subclavian arteries; the innominate veins and the upper
half of the superior vena cava; the left highest intercostal
vein; the vagus, cardiac, phrenic, and left recurrent
nerves; the trachea, esophagus, and thoracic duct; the
remains of the thymus, and some lymph glands.
It contains a quantity of loose areolar tissue, some
lymphatic vessels which ascend from the convex
surface of the liver, two or three anterior mediastinal
lymph glands, and the small mediastinal branches of the
internal mammary artery.
Middle:
contains the heart enclosed in the pericardium, the
ascending aorta, the lower half of the superior vena
cava with the azygos vein opening into it, the bifurcation
of the trachea and the two bronchi, the pulmonary artery
dividing into its two branches, the right and left
pulmonary veins, the phrenic nerves, and some
bronchial lymph glands.
Posterior:

It contains the thoracic part of the descending aorta, the
azygos and the two hemiazygos veins, the vagus and
splanchnic nerves, the esophagus, the thoracic duct,
and some lymph glands.


Other includes: azygous vein, thoracic duct, spinal cord
What Do We Worry About As Surgeons?

Injuries that kill early:



Injuries that kill late:


Tracheobronchial tree
Injuries that kill if missed:

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Heart
Great vessels
Esophagus
Azygous vein
Injuries that cause morbidity:



Thoracic duct
Spinal cord
Diaphragm
Additional Concerns:
Cardiac Box
Associated Injuries:
• Thorax:
• Chest wall
• Lungs
Mediastinum
Thoracoabdominal area
• Abdomen:
• Any structure
• Timing of
exploration
important
Asensio et al. World J Surgery, 2002
History of Penetrating Thoracic Trauma

Described in the Edwin Smith
Surgical Papyrus, dated 3000 BC,
written by Imhotep

First recorded “operation” for thoracic
trauma in North America


Cabeza de Vaca, 1635, described
removal of arrowhead from the chest
wall of an Native American
Contemporary management of
transmediastinal penetrating injuries
required mandatory exploration Bradley M.
Transmediastinal wounds. Am. Surg. 1966;32:847–852
Epidemiology of Penetrating Thoracic Trauma

150 000 people die a year secondary to trauma


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Urgent operative intervention only required in
2.8% of penetrating thoracic injuries
BUT
Mediastinal penetrating injuries have an increased
need for operation

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25% of deaths related to thoracic trauma
Unstable: 43% of pts - 100% to OR
Stable: 57% of pts - 35-60% to OR (Richardson et al., 1981)
Management dictated by hemodynamic status
But what does ‘stable’ mean?
2000
Can we triage patients based on blood pressure? (OR vs. investigations)
Prospective, N = 68

Group I = SBP > 100 mmHg
 Dx: CXR > PE > OR

Group II = SBP 60 – 100 mmHg
 Dx: CXR > PE > OR

Group III = SBP < 60 mmHg
 Dx: ED thoracotomy > death > OR
Conclusions:

CXR with PE can diagnose TM GSW in 90% of pts.
Indication for immediate OR
in stable patients:
massive hemothorax &
hemopericardium
2000

SBP > 100 mmHg?

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SBP 60 – 100mmHg?

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Resuscitate (50% still do not need surgery)
SBP < 60 mmHg?

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Investigate (60% do not need surgery)
Operate (100% need ‘surgery’)
Remember: 1/5 have an intraabdominal injury
Injury, 2013


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Prehospital transport times are better
More patients with TGSW are surviving to
hospital
They are ‘sicker’

87% were unstable on arrival (including VSA)


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84% required an ED thoracotomy (6% survival)
Only 8% managed non-operatively
Overall mortality 79%

If arrived with vital signs: 24%
Main Message

Get your ED thoracotomy tray ready

Some stable patients need to go to the OR

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Half (or less) will need surgery

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Positive pericardial FAST or massive hemothorax
Even if unstable, but all if in extremis
Don’t forget the abdomen
Algorithm for All Transmediastinal Injuries
In Extremis:
1.
ED thoracotomy

Hemodynamically unstable:
2.
CXR, FAST, bilateral chest tubes
To the OR


Hemodynamically stable:
3.
Diagnosis (CTA)

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Trajectory & injuries
Management
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Surgical vs. non-operative
How Do We Investigate the
Stable Patient?

Can helical CT scan reduce the need for further
investigations?
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N = 24 pts. mediastinal GSWs, HD stable
All pts. received a helical contrast CT scan
12 pts. required further imaging
 Bullet tract close to mediastinum – to OR
 All other studies negative, no missed injuries
Conclusion:
 50% of pts. had a change in management based on CT
scan
 Helical CT effective to evaluate missile trajectories to
assess for mediastinal injuries and avoid unnecessary
exams
Algorithm for Stable Transmediastinal Injuries
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Overt Injuries:
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Heart, great vessels
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Occult Injuries:
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To OR
Heart, great vessels
Tracheobronchial tree
Esophagus
Azygous vein
Thoracic duct
Patients with negative helical
CTAs can be safely observed

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What is our local experience with investigating TM GSWs in
stable pts.?

Work up depends on trajectory
NO CTA
Prospective, N = 50 pts.
All pts. had a CXR followed by either:

Cardiac ultrasound, angiography, esophagoscopy, barium
swallow and bronchoscopy
 8 pts. (16%) found to have a mediastinal injury (cardiac >
vascular > tracheoesophageal)
 42 pts. (84%) had no mediastinal injury
•

No difference between groups re: biochemical or clinical status
(including chest tube outputs)
Stable pts. may have life-threatening, occult injuries

Aggressive work-up needed in all to avoid missed injuries
Burack JH, et al. Triage and outcome of patients with
mediastinal penetrating trauma, Ann Thorac Surg. 2007
BACKGROUND:

What is our experience with CXR, ECHO & CTA scans in the evaluation of
stable patients with mediastinal penetrating trauma?
METHODS: Retrospective study, N = 207

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Unstable patients: OR
Stable patients: CXR, TTE and CTA.
Further testing (angiogram, bronchoscopy, esophagoscopy, esophagogram)
based on trajectory
RESULTS:
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35% were unstable, 26% died in the emergency department
CTA evaluation was normal in almost 80% of patients

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no further treatment needed
Occult injury found in 7% of stable patients
CONCLUSIONS:
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Unstable patients require surgery
Stable patients: TTE & chest CTA are effective screening tools
Patients with a negative TTE and CTA results can be observed
If TTE or CTA positive, exclude occult injury
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After thoracic CT scan
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Esophagoscopy
Esophageal swallow
Bronchoscopy
Angiography
Mandatory pericardial
window
OR:
 Selective investigation
depending on the trajectory
of the bullet
 83% of stable pts. had
negative CTAs with no
missed injuries
In the Stable Patient:
Is this a transmediastinal penetrating injury?
1.
CXR & physical exam
1.
Are mediastinal structures injured?
2.
Overt injuries requiring OR?
1.
CXR: massive HTX
FAST: positive presumed hemopericardium
1.
2.
Occult injuries requiring OR?
2.
CTA: trajectory
1.
1.
2.
3.
4.
Airways
Esophagus
Vessels
Heart
1.
Left HTX; false negative FAST
How Do We Operate?
Operative Approach

What is injured?

Great Vessels

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Massive hemothorax (unilateral or bilateral)
Large mediastinal hematoma on CXR
Heart

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FAST positive
FAST indeterminate, false negative

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? Left hemothorax
Ongoing blood loss from chest tube
Both
Both +/- other organs
Other organs (massive tracheobronchial injury)
Great Vessel Injury: Where to Cut?
Great Vessel Injury: Where to Cut?
Transmediastinal Injuries
Don’t forget about the
abdomen!
Asensio JA, Arroyo H Jr, Veloz W, Forno W, Gambaro E, Roldan GA, Murray J,
Velmahos G, Demetriades D. Penetrating thoracoabdominal injuries:
ongoing dilemma-which cavity and when? World J Surg. 2002 May;26(5):53943.
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N = 254 patients penetrating thoracoabdominal
injuries
20% underwent combined thoracotomy and
laparotomy
Mortality doubles if combined procedures are
required
Persistent hypotension more often in laparotomy
followed by thoracotomy group but numbers are too
small
Watch persistent hypotension and misleading chest
tube outputs
Where to Cut? Median Sternotomy

Principles:
 “Anywhere you need”

Median Sternotomy +/- cervical extension
(R or L):
 R subclavian artery, proximal R carotid,
brachiocephalic artery, proximal L carotid
artery
 NOT GOOD FOR L subclavian artery
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Too far posterior
3rd ICS anterolateral thoracotomy for
proximal control
Supraclavicular incision with resection of
medial 3rd of clavicle (distal control)
Median sternotomy (to join the incisions –
book / trap door)
 Rarely used
GOOD FOR concomitant cardiac injuries
Where to Cut? Bilateral Anterolateral
Thoracotomies
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
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Utility incision, access
to heart and aorta for
resuscitation
Can access right lung
hilum, ascending aorta,
right subclavian vessels
However problematic
for L subclavian artery
injuries
J Am Coll Surg 1999; 188:290-295


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Retrospective review
N = 79 pts. with penetrating subclavian or
axillary artery injury
Conclusion:



Clavicular incision alone provides adequate exposure in
50% of pts. (R and L)
In proximal injuries can use the addition of medial
sternotomy
More deaths seen with SCV injuries than SCA
Great Vessels – Surgical Principles

Great vessels are fragile,
tear easily with
dissection, therefore
oversew proximal injury
on aorta, sew graft into
new location on aorta
without tension

Use prosthetic graft for
vessels > 5 mm vs.
saphenous vein
(pseudoaneurysm vs.
acute rupture)

Dacron for fragile
vessels – aorta, SCA
Subclavian Artery Injuries

Pitfalls for SCA:



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Watch injury to phrenic nerve
when dissecting out SCA
Failure of proximal control with
3rd ICS
Failure to document brachial
plexus status pre-op
No tunica media, end to end
anastomosis doomed to fail
–

Interposition graft
Damage control:
1.
2.
Definitive repair of injuries with
quick & simple techniques in
one operation
Abbreviated thoracotomy to
restore survivable physiology
during a single operation
Cardiac Injuries


Unstable pts. may present
with tamponade or ongoing
blood loss from chest tube
Occult cardiac injuries may be
present in 5% to 10% of
patients after a TM-GSW
Feliciano D, et al. J. Trauma 2000;48:416–422


TTE is the diagnostic test of
choice in patients with
wounds traversing the
anterior mediastinum
When ECHO is used to
screen for pericardial fluid it is
97% sensitive, 100% specific,
and 99% accurate Nagy K, et al. J.
Trauma 1995;38:859 – 862
Esophageal Injuries

Incidence 0.7% after thoracic gun shot wounds

Transmediastinal gun shot wounds close to spine may
result in through and through injury

Delay in repair disastrous

Upper 2/3rds of thoracic esophagus:


Distal 1/3:


Right posterolateral thoracotomy
Left posterolateral approach (7th ICS)
Primary repair even if > 24 hrs

Grillo pleural patch & decortication



How long is too long when investigating esophageal injuries?
Retrospective, multicenter study, N = 45 pts.
 All pts. to OR, pre-operative evaluation vs. no evaluation
 13 hrs vs. 1 hr
 Increased complications, LOS in group evaluated (OR > 3)
Conclusion:
 Esophageal injuries carry high morbidity and mortality. Diagnostic
testing, if done, should be expeditious with delays to definitive
management reduced.
Tracheobronchial Injuries

Conservative:




Small injuries (< 1/3 diameter of airway)
Asymptomatic
Controlled with tube thoracostomy
No need for PPV


Operative:

R posterolateral thoracotomy for injuries of:





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Intrathoracic tracheal, right bronchial, and proximal left mainstem bronchus or complex
bilateral injuries
L posterolateral thoracotomy for injuries of:


Or place ETT beyond injury with cuff inflated below
Distal left bronchial injuries > 3 cm from carina
Mobilize anterior and posterior trachea as needed
Interrupted, absorbable sutures (4-0 Vicryl), sutures tied on the outside, end
to end anastomosis
Buttress repair with intercostal muscle
Suture chin to chest for healing
Follow up:


Pre-op baseline flow-volume loops
Beware later presentation of ‘adult asthma’

stricture
Tracheobronchial Injuries
Special Problems

Bullet embolization

Thoracic duct injury

Spinal cord

Azygous vein
Bullet (Foreign Body) Embolization



Bullet entry into large diameter vessels of
chest
Diagnosis frequently delayed as course of
bullet not always apparent
Usually lodges in femoral or iliac vessels


Control site of entry for hemorrhage first
Remove bullet emboli


Surgery
Endovascular methods
Special Problems

Thoracic duct leaks:


Chylothorax
Spinal cord injury


Always assess
neurologic function
pre-operatively
Neurogenic shock
may occur

C > T > L spine
Azygous Vein Injury and Repair
N = 22 patients over
40 years
Mortality 36%
Maintain an index of
suspicion when there
is continued dark
venous ooze from
behind the pulmonary
hilum
Posterolateral
thoracotomy best
exposure
Ligate the vein unless
no IVC
In Conclusion:
Is this a transmediastinal penetrating injury?
1.
CXR & physical exam
1.
Is your patient unstable?
2.
YES: Bilateral chest tubes, FAST, ED thoracotomy / OR
NO: investigate
1.
2.
Are mediastinal structures injured?
3.
Overt injuries requiring OR?
1.
CXR: massive HTX
FAST: positive presumed hemopericardium
1.
2.
Occult injuries requiring OR?
2.
CTA: trajectory
1.
1.
2.
3.
4.
Airways
Esophagus
Vessels
Heart
1.
Left HTX; false negative FAST
tzakrison@med.miami.edu
¡Muito obrigado!