A 21-year-old asymptomatic man had a pre-employment chest x-ray, which is shown. Four years ago he was stabbed in the left chest. The best management of this patient is

A. bronchoscopy and antibiotics.
B. decortication.
C. observation.
D. reduction and primary repair.
E. tube thoracostomy.

Answer D

It is estimated that 30% of all traumatic injuries to the diaphragm are diagnosed late. Stab wounds are the most common cause of delayed traumatic herniation. The risk of strangulation is high because the defect is usually small. Victims have few or no symptoms until the hernia contains a large volume of intra-abdominal contents or until bowel strangulates. If the diagnosis is not made until strangulation and perforation occurs, mortality is high. Rapid dilatation of bowel herniated into the chest can cause severe shortness of breath and may resemble a loculated pneumothorax on chest x-ray. 

Absence of a history of trauma does not rule out a delayed diaphragmatic injury. Once a delayed presentation of diaphragmatic injury is suspected, barium studies of the gastrointestinal tract are the most reliable means of confirming the diagnosis. While acute diaphragmatic hernias can be repaired through a laparotomy, chronic traumatic diaphragmatic hernias should be repaired via thoracotomy.