The chest cavity includes the heart and lungs. The abdominal cavity includes the liver, the stomach, and the small and large intestines. The two regions are separated by the diaphragm, the large dome-shaped muscle.

When the diaphragm develops with a hole in it, the abdominal organs can pass into the chest cavity. The lung tissue on the affected side is compressed, fails to grow normally, and is unable to expand after birth. As the child begins to breathe, cry, and swallow, air enters the intestines that are protruding into the chest. The increasing size of the intestines puts pressure on the other side of the chest, lung, and heart and can quickly cause a life-threatening situation.

The indications for a diaphragmatic hernia repair include:

• Chest X-rays showing diaphragmatic hernia
• Severe breathing difficulty (respiratory distress) shortly after birth
• Prenatal ultrasound often identifies a diaphragmatic hernia

An incision is made in the upper abdomen, under the ribs. The abdominal organs are gently pulled down through the opening in the diaphragm and positioned into the abdominal cavity.

The hole in the diaphragm is repaired and the incision is stitched closed. A tube is placed in the chest to allow air, blood, and fluid to drain so the lung can re-expand.

The lung tissue may be underdeveloped on the affected side, and the outcome depends upon the development of the lung tissue. Infants who survive may have some long-term lung disease.