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

Disclosure Statement: No Conflict of Interest May 28 – 30, 2015, Montréal, Québec 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.

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

Disclosure Statement I, Dr. Michael Patlas, have no affiliations, sponsorships, honoraria, monetary support or conflict of interest from any commercial source 4

5 Diaphragmatic Injury is an Old Diagnostic Conundrum 1591-Daniel Sennertus described autopsy findings of a gastric herniation due to traumatic diaphragmatic injury

6 Presentation 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

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

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 9

McMaster Experience January 1, 2008-December 21, 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

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 % ( Nchimi A. AJR 2005) 58 % - prospective identification of DI on MDCT (BDI-77%, PDI-47%); correct retrospective injury side determination in % ( Hammer MM. Emerg Radiol 2014) 11

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 12

Why Do We Struggle? Multitrauma patients with associated injuries in % 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

Why Do We Struggle? There is no herniation of abdominal organs in many cases of PI We have to rely on indirect signs 14

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) 15

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

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) Bodanapally UK. Eur Radiol

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) 18

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

Complications Stomach, colon, spleen and omentum herniate in cases of left-sided DI Liver herniates in right-sided DI Life-threatening complications- incarceration and ischemia of herniated organs 20

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 21

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 22

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25 Teaching Point: Combination of Different Direct and Indirect Signs

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28 Stab wound with 1.5 cm diaphragmatic defect

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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 36

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What happens if we miss? 38

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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 40

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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 42

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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 44

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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 46

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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 50

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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 53

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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 56

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58 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) 61

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

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) 63

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 64

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 Use MPRs to assess the diaphragm 65

Thank you! 66