Diaphragmatic Injuries:
Why Do We Struggle to Detect Them?
Michael N. Patlas, MD, FRCPC
Associate Professor of Radiology
Director, Division of Emergency/Trauma
Radiology
McMaster University, Hamilton, Canada
patlas@hhsc.ca
May 28 – 30, 2015, Montréal, Québec
Disclosure Statement: No Conflict of Interest
I do not have an affiliation, financial or otherwise, with a pharmaceutical company, medical
device or communications organization.
I have no conflicts of interest to disclose ( i.e. no industry funding received or other
commercial relationships).
I have no financial relationship or advisory role with pharmaceutical or device-making
companies, or CME provider.
I will not discuss or describe in my presentation at the meeting the investigational or
unlabeled ("off-label") use of a medical device, product, or pharmaceutical that is
classified by Health Canada as investigational for the intended use.
May 28 – 30, 2015, Montréal, Québec
Diaphragmatic Injuries:
Why Do We Struggle to
Detect Them?
Michael N. Patlas, MD, FRCPC
Associate Professor of Radiology
Director, Division of Emergency/Trauma Radiology
McMaster University, Hamilton, Canada
patlas@hhsc.ca
Disclosure Statement
• I, Dr. Michael Patlas, have no
affiliations, sponsorships,
honoraria, monetary support
or conflict of interest from any
commercial source
4
Diaphragmatic Injury is an
Old Diagnostic Conundrum
1591-Daniel Sennertus
described autopsy findings
of a gastric herniation due to
traumatic diaphragmatic
injury
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Presentation
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5 months later
Introduction
• The diaphragmatic injury (DI) is an uncommon
traumatic condition
• 0.8% - 8% of patients with blunt abdominal trauma
• Blunt DI (BDI) is undiagnosed at initial presentation in
7% - 66%
Desir A. RadioGraphics 2012
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Introduction
• Penetrating diaphragmatic injury (PDI) can be
occult in 7% of cases
• Diaphragmatic injury does not resolve
spontaneously & can cause disastrous
complications
Dreizin D. Radiology 2013
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Learning Objectives
1. To describe direct and indirect signs of blunt
and penetrating diaphragmatic injury (DI)
2. To highlight factors affecting detection of DI
3. To discuss pitfalls in diagnosis of DI
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McMaster Experience
• January 1, 2008-December 21, 2012
• 3225 trauma patients
• 38 patients with DI (B and P)
• 24 cases with 64MDCT before laparotomy
• Correct preoperative diagnosis in 16/24 cases
Leung V, Patlas M et al. CARJ 2015
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How Are We Doing in Real Life?
• 50% of BDIs had been diagnosed prospectively on
admission helical CT; retrospective review of the same
cases showed sensitivity of 56 - 87% (Nchimi A. AJR 2005)
• 58 % - prospective identification of DI on MDCT
(BDI-77%, PDI-47%); correct retrospective injury side
determination in 91 - 94% (Hammer MM. Emerg Radiol 2014)
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Why Do We Struggle?
• Trauma patients are poor historians
• Referring physicians are not always good historians
• Uncommon injury
• Lack of awareness by clinicians and radiologists
• There are no specific clinical signs of diaphragmatic
injury
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Why Do We Struggle?
• Multitrauma patients with associated injuries
in 52-100% of cases
• Right-sided defects are difficult for detection due to
lack of contrast between diaphragm and liver
• Tiny defects in penetrating injury (PI)
Rees O. Clin Radiol 2005
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Why Do We Struggle?
• There is no herniation of abdominal
organs in many cases of PI
• We have to rely on indirect signs
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Which side-BDI?
BDI occurs more often on the left side
(L to R ratio of 3:1)
•
Protective effect of liver on the right side
•
Area of congenital embryological weakness
in the posterolateral aspect of the left
hemidiaphragm
Greater inherent resistance of the right
•
hemidiaphragm (Patlas M. Radiol Med 2015)
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Which side-BDI?
• Steering wheel on the left side of the car in
most countries
• Underdiagnosis of right-sided BDI (subtle
signs, high mortality due to associated
injuries)
Desir A. RadioGraphics 2012
16
Which side-PDI?
•
No predilection for side is seen with GSW
•
The majority of stab wounds are on the left
side (high percentage of right-handed
attackers)
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Bodanapally UK. Eur Radiol 2009
Site and Size
•
BDI usually located at posterolateral area
•
BDI-large tears (more than 10 cm)
•
No predilection for site with GSW
•
Small size of PDI (1-2 cm)
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Complications
• Spontaneous healing of DI has never been reported
• Negative pleuroperitoneal pressure gradient
contributes to the persistence of the defect
• Abdominal structures herniate into thorax
Leung V, Patlas M et al. CARJ 2015
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Complications
• Stomach, colon, spleen and omentum
herniate in cases of left-sided DI
• Liver herniates in right-sided DI
• Life-threatening complicationsincarceration and ischemia of herniated
organs
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Imaging Signs on MDCT
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Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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Teaching Point: Combination of Different
Direct and Indirect Signs
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Stab wound with 1.5 cm
diaphragmatic defect
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1
2
3
4
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Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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• What happens if we miss?
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Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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43
Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
44
45
Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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Imaging Signs on MDCT
Direct signs:
•
Segmental diaphragmatic defect
•
Dangling diaphragm
Indirect signs:
•
Herniation through the defect
•
Collar
•
Hump and Band
•
Dependent viscera
•
Thickening of the diaphragm
•
Contiguous injury
•
Pneumothorax and pneumoperitoneum
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• Atraumatic
defect
• Most often on
the left side
• Elderly
patients
• Small defects
• No
additional
signs of DI
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How can we help ourselves?
• Obtain as much clinical information as you can:
42% of penetrating DI happen in patients with
entry wounds in thoracoabdominal area
defined by nipple line superiorly and costal
margin inferiorly (Bodanapally UK et al. Eur Radiol 2009)
• Use your best scanner to evaluate trauma
patients (speed and resolution)
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How can we help ourselves?
• Remember anatomic variants
Small gap in posterior diaphragm between crura
and lateral arcuate ligaments is seen in 11% of
population, more often in elderly people
Restrepo CS et al. RadioGraphics 2008
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How can we help ourselves?
• Check all phases for signs of DI (arterial and
delayed phases for wound tract outlined by the
blood, portal phase for the band sign)
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How can we help ourselves?
• MPRs (dangling diaphragm, hump and
band signs, collar sign)
• Don’t misinterpret band sign as linear
hepatic laceration
• ALWAYS SUSPECT DIAPHRAGMATIC
INJURY
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Conclusions
•
We have to rely on indirect signs in many
cases due to low sensitivity of direct signs
•
Small rents in PDIs present a diagnostic
challenge
•
Think about trajectory
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Thank you!
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