This patient actually had a hernia sac that extended into the thoracic cavity. A sac is not very common in diaphragmatic hernias as it implies that the diaphragm had actually closed. Most likely it represents a late defect when the pleuroperitoneal membranes have just closed but before they have much structural integrity, leading to the sac in the chest. The fact that this child’s lungs were quite stable pre-operatively also suggests a late defect.
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