Jejunal perforation following blunt abdominal trauma

Clinical History

Hypovolemia and sensitivity of the abdomen following blunt abdominal trauma.

Imaging Findings

The patient was involved in a motor vehicle accident. Clinical examination on admission was unremarkable. Ultrasound examination showed a small amount of fluid in the pouch of Douglas, so the patient was held for observation. On the second day she developed hypovolemia and sensitivity of the abdomen. A CT scan was performed on an emergency basis using iv contrast. Oral contrast was given immediately before the examination. The findings were: a contusion in segments V, VI and VII of the liver, a large amount of intraperitoneal fluid involving th pouch of Douglas, the mesentery, the right and left paracolic gutters and Morrison's space; pneumoperitoneum with a large quantity of intraperitoneal air; and bowel wall thickening involving the jejunum. No extravasation of oral contrast was observed. The diagnosis was contusion in segments V, VI and VII of the liver and jejunal perforation, which was treated surgically.

Discussion

CT is regarded as highly accurate in depicting injuries to solid abdominal organs, but it is a challenge for the radiologist to use it to detect bowel injuries. Bowel and mesenteric injuries are found in approximately 5% of patients with blunt abdominal trauma. Clinical signs are often subtle and delay in treating patients with bowel injury increases morbidity and mortality. Therefore CT plays an important role as a useful imaging modality in evaluating patients presenting with blunt abdominal trauma.

There are a variety of CT signs in bowel injury, with different sensitivities and specificities. The combination of these signs increases the diagnostic capability. A highly specific sign of bowel perforation is extravasation of oral contrast medium, but it is not a common finding. The presence of extraluminal gas is both specific and sensitive, though in some cases pneumothorax and pneumomediastinum can cause pneumoperitoneum. Also pneumatosis cystoides intestinalis and the previous use of peritoneal lavage may mislead the diagnosis. Moderate or large amounts of free fluid without evidence of solid organ injury is a finding suggestive of bowel injury, especially if this is combined with bowel wall thickening or if the collection is in the mesentery or bowel wall. Small peritoneal collections in the pelvis of women of reproductive age are most likely of no importance. Bowel wall thickening is a quite sensitive finding, but with low specificity since is found in a number of other conditions and must be combined with other findings such as mesenteric infiltration or active haemorrhage in order to produce the diagnosis of bowel trauma. Other helpful signs are associated pancreatic or renal lacerations, traumatic disruption of abdominal wall muscles and seat belt ecchymosis of the abdominal wall. Radiologists must be alert when assessing a patient with blunt abdominal trauma using CT in order to recognise the signs of the not so uncommon bowel injury.

Differential Diagnosis List

Final Diagnosis

Jejunal perforation, liver contusion

URL:	https://www.eurorad.org/case/1611
DOI:	10.1594/EURORAD/CASE.1611
ISSN:	1563-4086