Traumatic Diaphragmatic Rupture

Michael P. Federle, MD, FACR

Key Facts

Imaging

Due to blunt and penetrating trauma
Best imaging clue: Discontinuity of hemidiaphragm with “fallen” or “dependent” viscus sign
90-98% occur on left side
Herniated organs: Stomach > omentum, colon, small bowel, spleen, liver
Associated injuries are found in most cases
Plain film signs: Lower thoracic soft tissue density
- Herniated fluid-filled hollow viscus or solid organ
Lower thoracic abnormal gas density
- Herniation of hollow viscus
Loculated hydropneumothorax may also be present
- Hard to distinguish from diaphragmatic rupture
CT signs: Discontinuity of hemidiaphragm
Intrathoracic herniation of abdominal contents
“Collar” sign: Waist-like constriction of stomach or colon at site of diaphragmatic tear
Abdominal contents lateral to diaphragm
“Fallen” or “dependent” viscus sign
- Herniated viscus abuts posterior ribs, spine, thoracic wall
Helical CECT with multiplanar reformations: Best initial study
MR most accurate but not practical for unstable patient
“Dangling diaphragm” sign
- Free edge of torn diaphragm curls inward

Top Differential Diagnoses

(Left) Chest x-ray in a young man following a motor vehicle crash shows a pneumothorax, chest tube, and an NG tube that is curved up toward the chest

. (Right) Axial CT in the same patient shows all the typical signs of diaphragmatic injury, including the “fallen” viscus sign. The stomach

lies in the chest. Note that it has “fallen” medially and posteriorly to lie against the posteromedial chest wall. The stomach appears “pinched”

as it traverses the defect in the diaphragm (“collar” sign).

(Left) Coronal reformation of the CT in the same patient shows the herniated stomach

being “pinched” as it traverses the defect in the diaphragm

. (Right) Sagittal reformation of the CT sections in the same patient shows the herniated stomach

and its constriction

as it passes through the defect in the diaphragm.

TERMINOLOGY

Synonyms

Definitions

IMAGING

General Features

Best diagnostic clue
- Discontinuity of hemidiaphragm with “fallen” or “dependent” viscus sign
Location
- 90-98% occur on left side
  - Posterolateral part of diaphragm, medial to spleen
Size
- Blunt trauma
  - Most tears are large (> 10 cm in length)
- Penetrating trauma
  - Gun shot wounds (blast injuries) → large defects in diaphragm
  - Stab wounds → shorter lacerations
    - More likely to have delayed diagnosis
    - Initial short laceration may be overlooked; enlarges over time
Morphology
- Curvilinear lacerations
Key concepts
- Due to blunt and penetrating trauma
- Occur in 1-5% of all blunt trauma victims
- Accounts for 5% of all diaphragmatic hernias
  - Hiatal, Bochdalek, and Morgagni hernias are much more common
- 90% of all strangulated diaphragmatic hernias are due to trauma
- Herniated organs: Stomach > omentum, colon, small bowel, spleen, liver