CASE 1518 Published on 19.03.2002

Incomplete intestinal obstruction

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

R. Jelassi, F. Réty, JC Le Van An, M. Brauner

Patient

73 years, female

Categories
No Area of Interest ; Imaging Technique CT, CT, CT
Clinical History
The patient was admitted with acute diffuse abdominal pain, nausea and vomiting. Physical examination showed a soft non-tender abdomen, decreased bowel sounds and no fever.
Imaging Findings
The patient was admitted with acute diffuse abdominal pain, nausea and vomiting. Her medical history was limited to hysterectomy. Physical examination showed a soft non-tender abdomen, decreased bowel sounds and no fever. The following laboratory investigations were normal or negative: white blood cell count, C reactive protein, liver and renal function tests, and amylase level. Abdominal plain film showed air in the biliary tree and no other abnormality. Computed tomography (CT), which was quickly performed, revealed pneumobilia, cholecystoduodenal fistula, a gallstone impacted in the ileum and dilated loops of small bowel above the stone.

Because of the diagnosis of gallstone ileus made on the CT scan, an emergency laparotomy was performed. A gallstone was identified within the ileum.

Enterolithotomy alone was performed. The patient had no biliary symptoms on follow-up.

Discussion
Gallstone ileus in the elderly patient is an uncommon complication of chronic cholecystitis and is difficult to diagnose clinically and radiologically. Gallstone ileus accounts for 1% of all small bowel obstruction. The mortality rate is high and results from concomitant disease and delayed diagnosis.

Gallstone ileus results from a bilioenteric fistula with impaction of one or more gallstones anywhere betwen the stomach and rectum. Three quarters of fistulae occur between the gallblader and duodenum. A gallstone must measure at least 2cm in diameter to impact in the bowel. Terminal ileum, which is the narrowest part of the bowel, is the most frequent site of obstruction. Bouveret syndrome is uncommon and is caused by impaction of a gallstone in the duodenal bulb.

Clinical features of gallstone ileus are rarely specific. Intermittent symptoms of incomplete intestinal obstruction are seen but are non-specific. Previous pathology of the biliary tree or of the gallblader is seen in 30-60% of cases. The classic radiographic triad of Rigler, which associates features of pneumobilia, ectopic gallstone and small bowel obstruction, is pathognomonic of gallstone ileus. However, these three radiological features are only present in 30% of cases of gallstone ileus. Each one of these three radiological signs by itself is not specific of gallstone ileus.

Ultrasound may show air in the biliary tree and in the gallblader, a calcified ectopic gallstone and dilated small bowel loops, which are most frequently filled with large quantities of liquid but little gas. However, the usefulness of this imaging modality is highly dependent on the patient's echogenicity and on the skills of the operator.

CT imaging is probably the best imaging modality for the diagnosis of gallstone ileus. It allows good visualisation of pneumobilia, cholecystoduodenal fistulae and moderately or uncalcified ectopic gallstones. Moreover, CT scanning confirms intestinal obstruction, especially when bowel loops are fluid-filled but with little gas, and shows the site of the obstruction.

Differential Diagnosis List
Gallstone ileus
Final Diagnosis
Gallstone ileus
Case information
URL: https://www.eurorad.org/case/1518
DOI: 10.1594/EURORAD/CASE.1518
ISSN: 1563-4086