Congenital diaphragmatic hernia.
Examination of the initial chest film demonstrates multiple loops
of herniated bowel in the patient's left chest cavity. This is
causing significant mass-effect with associated rightward
mediastinal shift. Following repair there is residual mediastinal
shift. In addition, a small hypoplastic left lung is seen.
Congenital diaphragmatic hernias are secondary to diaphragmatic
weakness. This is classically posterior i.e Bochdalek hernia. The
hernias themselves are more common on the left (5:1). This is
thought to be secondary to the presence of the liver. Patient's
with diaphragmatic hernia generally present with respiratory
distress. The radiographic appearance depends on the quantity of
air within the herniated viscera. The initial exam may be
radiopaque as no air has entered the bowel. Once air is introduced
into the bowel, air-filled viscera that extends from the abdomen
into the chest cavity is diagnostic. In questionable cases a NG
tube can be inserted to confirm the diagnosis. The herniated
contents will cause hypoplasia of the patient's lungs secondary to
compressive effect. The patient's mortality rate is directly
related to the degree of pulmonary hypoplasia. Poor prognostic
indicators are lack of aerated ipsilateral lung, severe mediastinal
shift and poor aeration in the contralateral lung.
Donnelly, Lane F. Fundamentals of Pediatric Radiology W B Saunders
Co; March 9, 2001