Clinical History
A 62-year-old man was admitted to E.R. for abdominal pain. The patient reported having undergone a hepatectomy for a giant haemangioma of the liver some years before. He had no history of trauma. The physical examination revealed mild abdominal tenderness and decreased breath sounds in the right hemithorax. The laboratory findings were unremarkable.
Imaging Findings
The X-ray of abdomen showed dilatation of the right colon and small bowel with multiple air-fluid levels. Above the right hemidiaphragm a large gas collection was present.
The chest X-ray showed small right-sided pleural effusion and herniation of large bowel into right hemithorax with focal constriction of the bowel at the site of herniation (collar sign).
These findings are suggestive of intestinal occlusion due a diaphragmatic hernia.
To obtain a more precise diagnosis an enhanced CT examination was performed.
CT examination shows post-hepatectomy surgical changes with compensatory hypertrophy of the left lobe of the liver and confirms the bowel loop in the right thorax and the dilatation of the right colon with multiple air fluid levels.
The coronal and sagittal reformatted CT images show the 'collar sign', where the large bowel passes through the discontinuity of the diaphragm.
The diagnosis was confirmed by surgery.
Discussion
The diaphragmatic hernia is an abnormal opening in the diaphragm that allows the migration of a part of the abdominal organs into the chest cavity. This condition, in adulthood, is usually caused by blunt or penetrating trauma of lower thorax or upper abdomen frequently associated with other lesions of the thoracic and abdominal organs. [1].
More common on the left side, owing to hepatic protection and increased strength of the right hemidiaphragm. Non-traumatic diaphragmatic hernia is very rare, most frequently encountered in patients undergoing laparotomy or hepatectomy because of injury to the diaphragm that can occur during surgery. [2, 3, 4]
A fundamental role in the formation of this iatrogenic hernia plays the delayed healing caused by constant motion of the diaphragm, the differential pressure between abdominal and thoracic cavities and the thickness of musculature of the diaphragm.
The herniation of abdominal contents can occur a long time after diaphragmatic injury and can worsen over time. [2]
The lesion can be asymptomatic. The symptoms can be very variable and depend on the organs involved and the size of the lesion. These include abdominal and chest pain, nausea, vomiting, abdominal obstruction, dyspnoea and acute respiratory distress.
The diagnostic imaging is essential for the diagnosis. Frequently the first step is conventional radiology, which can show: elevation or non visualisation of the hemidiaphragm (absent diaphragmatic sign), discontinuity of the diaphragm, pleural effusion, atelectasis, shift of the mediastinum, gas bubbles or loops bowel above the diaphragm. [5]
Other imaging techniques such as barium meal or barium enema used in the past have been abandoned for CT examination, the most effective diagnostic tool and most useful in assessing this disease. [6]
CT examination identifies more readily the content of intrathoracic herniation of solid abdominal viscera or omentum, can better highlight the discontinuity of the diaphragm and shows a focal constriction from compression of the bowel at the site of the tear in the diaphragm (collar sign).
A diaphragmatic hernia is an emergency that requires surgical treatment to place the abdominal organs into the proper position and repair the opening in the diaphragm with resection of organs and bowel segments not longer viable.
The prognosis is generally good after surgery.
Differential Diagnosis List
Post hepatectomy non-traumatic right diaphragmatic hernia
Congenital diaphragmatic hernia
Eventration or paralysis of hemidiaphragm
Final Diagnosis
Post hepatectomy non-traumatic right diaphragmatic hernia
