The lesion is secondary to failure of development of the posterolateral portion of the diaphragm (resulting in persistence of the foramen of Bochdalek) The left side is affected in 90% of cases.  Indeed, if the right side is affected, one should consider other structural lung lesions (such as a cystic adenomatoid malformation) in the differential diagnosis.

Survival is approximately 50%.  Antenatal detection has been associated with a worse prognosis, but with the routine use of antenatal ultrasound most are now detected antenatally and this in itself is not necessarily a risk factor for poor outcome. However, risk factors for mortality include polyhydramnios and other associated anomalies (including Trisomy 18 and 21).  Approximately 40% of infants with CDH have other abnormalities.

Delivery room management involves intubation and decompression of the stomach with an orogastric tube. Initial stabilisation may involve muscle relaxation and sedation. Infants frequently require treatment with inhaled Nitric Oxide and HFOV. There is no need to urgently repair the defect and studies have demonstrated that delaying surgery until the degree of pulmonary hypoplasia can be determined and the pulmonary vasculature is more stable does not result in an increased mortality. In general, ECMO is rarely indicated for infants with CDH.

Clinical examination may show severe cyanosis, a scaphoid abdomen, reduced or absent air entry on the affected side, and occasionally bowel sounds may be heard in the chest.  Rarely, a diaphragmatic hernia may be an incidental finding in an older child.

The radiographs to the left demonstrate a left-sided CDH. The initial radiograph demonstrates the stomach in the left hemithorax. The follow-up radiograph clearly shows air in the small intestine within the chest cavity.  There is mediastinal shift to the right.

In the images below, another left-sided CHD is demonstrated.  The first film demonstrates a more convincing pattern of bowel in the left hemithorax.  There is mediastinal shift to the right.  The next film shows the appearances after surgical repair of the defect.

Lateral decubitus image

There are several identified types, based largely on the solid, microcystic, or macrocystic components of the lesion.  Solid lesions have a worse prognosis than large cysts.

There may be "regression" of the lesion in utero and the chest radiograph at birth may be essentially normal.  At the other extreme, there may be significant respiratory distress at birth and the baby may require urgent surgery.

The radiographs and CTs are of a preterm infant with a large CCAM.  He had very little respiratory difficulty at birth but there was increasing tension in the lesion, for which he required surgical resection acutely after an unsuccessful attempt at continuous drainage.

Lateral decubitus image

In the example to the left, this baby was noted to have a cystic air-filled mass in the left lung when being x-rayed for concerns about the abdomen. The baby had recently had an episode of culture-negative pneumonia in the NICU. The lateral shows an air-fluid level in the left hemithorax.

The lesion then becomes more opaque. The baby then had a suppurative discharge into his airways. The CT shows a thick-walled cystic mass in the left hemithorax consistent with an abscess.

Cultures were negative but he was treated with a prolonged course of antibiotics, resulting in radiographic resolution of the mass (final image).

In the image to the left, this baby was intubated for respiratory distress.  A nasogastric tube was passed but unable to be inserted fully.  On the chest radiograph, the nasogastric tube is seen in the left main bronchus, and ending in the left lower lobe.  Laryngoscopy confirmed the presence of an extensive laryngotracheooesophageal cleft extending from larynx to carina.