Learning Radiology xray montage
 
 
 
 
 

Congenital Diaphragmatic Hernias
Bochdalek Hernia

 

 General Considerations

  • If defective development, diaphragmatic hernia develops

Anterior – Morgagni

  • Anteromedial parasternal defect (Space of Larrey)
  • Maldevelopment of septum transversum
  • Tends to occur in overweight, middle-aged, women
  • Right > left (heart protects)
  • Usually not large
  • Usually unilateral
  • Associated with
    • Pericardial defects
    • Omental fat in pericardial space

Posterior – Bochdalek

  • Most common
  • Occurs through old pleuroperitoneal canals
    • Just lateral to the spine on either side
  • More frequent on left side
    • Possibly due to “protection” of right-side by liver
  • Hernia may contain intestine, stomach, spleen, liver or omentum
  • If hernia occurs on right
    • Intestine and liver or only liver may herniate
  • If the defect is large, newborns usually present with
    • Severe respiratory distress
    • Cyanosis
    • Scaphoid abdomen
  • Entire diaphragm is almost never absent
    • Some part of diaphragm is usually found at surgery, even if defect is very large
  • Hypoplasia of ipsilateral lung occurs from mass effect of bowel
  • Most often these are isolated congenital abnormalities
  • But they can have
    • Congenital Heart Disease
    • 13 ribs
    • Malrotation of GI tract frequently present

Imaging findings

  • Initially, hemithorax may appear opaque because loops are fluid-filled
  • Paucity of bowel loops beneath the diaphragm
  • Once air swallowing begins, multiple lucencies contained within bowel are seen in chest
    • Respiratory distress may increase as intestine occupies more of thorax
  • Some loops may remain fluid-filled
  • Mediastinal shift to the opposite side
  • Relative paucity of gas in abdomen
    • If stomach remains in abdomen, it is more centrally located than normal
  • Contrast through an NGT is diagnostic but often not needed

Differential diagnosis of lucent cysts in infant lung

  • Cystic adenomatoid malformation
  • Staphylococcal pneumonia
    • In both, abdomen contains normal amount of air-filled loops
  • Delayed herniation of bowel may occur in older infants following streptococcal pneumonia

Mortality around 50%

  • Pulmonary hypoplasia
  • Persistent Fetal Circulation Syndrome

Treatment

  • Surgical repair
  • Many demonstrate ipsilateral pulmonary hypoplasia for years after repair
  • Obstructive emphysema can occur in either lower lobe       

 Bochdalek Hernia

 
Bochdalek Hernia. Two axial images from a contrast-enhanced CT of the abdomen reveal a fatty density protruding through a rent in the posterior aspect of the right hemidiaphragm. The density represents omental fat which has herniated through a small Bochdalek hernia.