Post-traumatic left diaphragmatic rupture with intrathoracic stomach herniation

Clinical History

A 22-year-old male patient with no medical history was admitted to our department for an abdominal CT after abdominal trauma following a high-speed traffic accident. The patient presented immediately after the trauma with breathing difficulties and a stable haemodynamic status.

Imaging Findings

Clinical evaluation revealed a fracture of the femur and the left iliac wing.
Chest radiography showed an elevation of the left diaphragmatic dome with an irregular aspect of its distal end (Fig. 1).
Abdominal ultrasound revealed a pelvic effusion with a suspicion of a dehiscence of the bladder wall that made an abdominal CT necessary.
Abdominal CT revealed an elevation of the left diaphragmatic dome with a defect measuring 2 cm with a gastric trans-diaphragmatic hernia, which was best seen on the sagittal reformation (Fig. 2).
The so called "collar sign", consisting of a constriction of the stomach at the site of the diaphragmatic tear, was seen on the coronal reformation (Fig. 3). The dependent viscera sign was shown on the axial section: the stomach was in direct contact to the posterior chest wall because it was not supported by the injured diaphragm (Fig. 4a).

Discussion

Diaphragmatic rupture often results from blunt abdominal trauma, which is usually associated with motor-vehicle accidents and hence is predominant among young men. Estimated incidence is ~4.5% (range 0.8-8%) of patients who suffer blunt abdominal or lower thoracic trauma [1, 2]. The most common herniated viscera are the stomach and colon. The left hemidiaphragm is involved 3 times more frequently than the right, possibly because the liver has a buffering effect.
Clinical presentation varies depending on the mechanism of injury (blunt vs penetrating) and the presence of associated injuries. Symptoms of diaphragmatic injuries are frequently masked by associated injuries. As the diaphragm is integral to normal ventilation, injuries can result in significant ventilatory compromise. A history of respiratory difficulty and related pulmonary symptoms may indicate diaphragmatic disruption [3], in fact our patient had breathing difficulties immediately after the accident.
Diaphragmatic tears rarely occur in isolation. These patients often have associated thoracic and/or abdominal injuries or may have concomitant head or extremity trauma as is the case of our patient who had a fracture of the femur and a dehiscence of the bladder wall.
Chest radiography is the most important diagnostic technique, it can show a blurred and irregular aspect of the hemidiaphragm, an elevation of the diaphragmatic dome, an intrathoracic bowel pattern or presence of nasogastric tube in the chest [3].
In abdominal CT, direct discontinuity of the hemidiaphragm (Fig. 2) may be seen with or without intrathoracic herniation of abdominal contents. CT may show characteristic signs of diaphagmatic rupture including: the collar sign (a waist-like constriction of the herniating hollow viscus at the site of the diaphragmatic tear, which is classic for diaphragmatic rupture (Fig. 3)) ; the dependent viscera sign (when a patient with a ruptured diaphragm lies supine at CT examination, the herniated viscera are no longer supported posteriorly by the injured diaphragm and fall to a dependent position against the posterior ribs (Fig. 4a); focal diaphragmatic thickening; thoracic fluid abutting the abdominal viscera [4].

MRI may aid diagnosis because it visualizes the diaphragm’s anatomy. It is indicated in cases of uncertain diagnosis in a patient with stable condition, in cases of patient who will not be explored surgically or for late diagnosis [3].

Differential Diagnosis List

Final Diagnosis

Left diaphragmatic tear with intrathoracic herniation of the stomach

URL:	https://www.eurorad.org/case/13012
DOI:	10.1594/EURORAD/CASE.13012
ISSN:	1563-4086