diaphragmatic hernia (foramen of Bochdalek)
Last reviewed 01/2018
A foramen of Bochdalek hernia is a congenital disorder of the diaphragm that frequently presents as a neonatal emergency.
The hernia tends to be large and may present as respiratory distress shortly after birth. It often strangulates. The prevalence of Bochdalek hernia is about 1/2200 births.
On chest radiography the hernia is seen as a round or oval mass or air-filled viscus in the posterior mediastinum, more commonly on the left hand side. It may be confirmed by barium studies of the gut and an excretory urogram.
Previously it was believed that reduction of Bochdalek hernia should be performed as an emergency following birth. More recent evidence has however demonstrated that a delayed surgical approach that enables preoperative stabilization decreases morbidity and mortality. This change in clinical practice is due to the understanding that pulmonary hypoplasia, surfactant deficiency and primary pulmonary hypertension are largely responsible for the outcome of CDH and that the severity of these pathophysiologies is largely predetermined in utero. The pathophysiology of these processes does not appear to be exacerbated postnatally by herniated viscera in the chest as long as bowel decompression is continuous using a nasogastric tube and medical stabilization is achieved.
The ideal timing for repair of a Bochdalek hernia is unknown. Some surgeons suggest that repair 24 hours after stabilization is ideal - however delays of up to 7-10 days are often well tolerated. Often surgeons will delay the operation until normal pulmonary artery pressures have been maintained for at least 24-48 hours.
Note that rarely, hernias remain clinically silent until adulthood and may present as a life-threatening surgical emergency.
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