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Findings: There is a left-sided diaphragmatic hernia with an intrathoracic stomach and multiple air-filled bowel loops in the left hemi-thorax. Mass effect with mediastinal shift from left to right is present. There is minimal aerated right lung, and no aerated left lung. Additionally, an ET tube is identified with tip at the Caring tip of feeding tube projecting over the stomach, and an umbilical venous catheter overlying the T- 12 vertebral body.

Diagnosis:Congenital Diaphragmatic Hernia: Bochdalek Hernia

Discussion: A congenital diaphragmatic hernia (CDH) is a displacement of abdominal contents into the thoracic cavity through a defect in the diaphragm. The most common type of CDH is the posterolateral or Bochdalek hernia which occurs in approximately 1 per 3000 live births (M:F=2:1). Hernias through the foramen of Morgagni are rare and represent 2 to 4% of all CDH.

The Bochdalek hernia results from failure of the pleuroperitoneal space to close prior to the return of the bowel to the abdominal cavity during week 8 to 10 of early fetal life. The pleuroperitoneal space is closed by the development of the diaphragm. If the bowel returns to the abdomen prematurely or if there is delayed or incomplete formation of the diaphragm, a CDH develops. Bochdalek hernias occur on the left side 75% of the time. This is most likely secondary to the fact that the pleuroperitoneal canal closes earlier on the right. About 3% of affected children have bilateral hernias. Portions of the Gl tract are usually found in left-sided hernias; whereas, the liver may be present in the thorax with right-sided hernias which account for much of the morbidity and mortality associated with CDH.

Ipsilateral pulmonary hypoplasia results from compression of the affected lung by the herniated Gl contents. Although to a lesser degree, contralateral pulmonary hypoplasia is frequently present secondary to shifting of mediastinal structures. Respiratory distress with cyanosis and dyspnea is apparent shortly after birth. The abdomen may be scaphoid in cases of extensive displacement. Most affected neonates are intubated and resuscitated and when stabilized undergo surgical repair. Pulmonary hypertension often complicates the pre- and postoperative course. Even the use of the extracorporeal membrane oxygenation (ECMO) has only marginally improved the prognosis. In most centers, overall mortality rate remains about 50%.

Malrotation is a common associated anomaly in 95% of affected children secondary to interruption of the nommal rotation that occurs as the bowel returns to the abdomen. Other associated anomalies include neural tube defects (30%) and cardiovascular lesions (20%) such as ventricular septal defects and tetralogy of Fallot.

References:
1. Biickman JG. Pediatric Radiology: The Requisites. St. Louis: Mosby,1994, pp 16-19.

2. Gore RM, Levine MS, Laufer I. Textbook of Gastrointestinal Radiology. Philadelphia:
WB Saunders, 1994, pp 1391-1394.

3. Kirks DR. Practical Pediatric Imaging, 2nd Ed. Boston: Little/Brown, 1991, pp 742- 744.

4. Swischuk LE. Imaging of the Newborn, Infant, and Young Child, 3rd Ed. Baltimore:
Williams and Wilkins, 1989, pp100-105.

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