Congenital Diaphragmatic Hernia

KEY FACTS

Imaging

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Congenital diaphragmatic hernias (CDH) are most commonly left sided (80-90% of cases) through posterior foramen of Bochdalek
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  Stomach usually in chest
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  Deviation of heart toward right chest wall
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  80-85% contain herniated liver (liver up)
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    Liver up confers poorer prognosis
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Right-sided hernias all contain liver ± gallbladder ± bowel
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Be suspicious of bilateral hernias when stomach is in chest but little mediastinal shift
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Calculate lung:head ratio (LHR)
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  Area of lung contralateral to CDH divided by head circumference (all measurements done in mm)
  - –
    
    Trace periphery of visible lung to calculate area
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    < 1.0 high mortality; significant morbidity in survivors
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    1.0-1.4 extracorporeal membrane oxygenation usually required
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    > 1.4 better outcomes
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Associated abnormalities in up to 50% of cases
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  Structural anomalies (especially cardiac), aneuploidy, and many syndromes all reported

Scanning Tips

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Confirm CDH findings are real
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  Oblique axial image may simulate CDH
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  Check ribs; if multiple ribs seen, axis is incorrect
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Imperative to view entire diaphragm in sagittal plane
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  Coronal view of anterior diaphragm may be normal
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Higher frequency transducers helpful for differentiating herniated bowel vs. liver
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  Use color looking for hepatic and portal veins
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Document stomach position
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  More posterior position suggests liver also herniated
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  From least to most aberrant: Anterior left chest (likely no liver herniation), midposterior left chest, retrocardiac right chest

This incorrect scan plane creates the erroneous appearance of a CDH. Note there is a single rib on the downside

and multiple ribs

on the upside, indicating this image is severely obliqued.

Graphic of a liver-up, left-sided CDH shows the left lobe of the liver

pushing the stomach posteriorly

. Note that the anterior diaphragm

remains intact, stressing the importance of the sagittal plane when evaluating the diaphragm. If viewed only in the anterior coronal plane, a CDH could be missed.

Axial ultrasound at the level of the heart

shows both the stomach

and bowel

are herniated into the chest cavity. The anterior position of the stomach suggests the liver is not herniated (liver down). Always evaluate the contralateral lung (calipers).