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. 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.