Clinical History
In combination with small bowel obstruction, the diagnosis of gallstone ileus was made.
Imaging Findings
A patient was admitted to the hospital with complaints of severe abdominal pain in the right hypochonder and flank. The pain had started a few weeks before, but had become worse and colicky during the last two weeks. The pain was accompanied by vomiting and diarrhea. Physical examination revealed no fever nor signs of jaundice. Laboratory studies revealed abnormal liver function tests.
Plain conventional radiography of the abdomen in the supine position shows markedly dilated and air-filled small bowel loops
in right flank and supravesical regions. No distension of the colon is noted. An oval opacity with faint peripheral calcification
(arrow) and diameter of at least 2.5 mm is seen in the right fossa. There is a pneumo-cholangiogram sign at the left liver lobe
(arrowhead).
Contrast enhanced CT scan of the abdomen includes section at the level of the liver which shows non dilated intrahepathic bile ducts filled with air in the left liver lobe, and section at the level of the right iliac fossa which
demonstrates large laminated opacity (arrow) in a distended ileal loop.
Photograph of the extracted stone, measuring 2.5 x 2.5 x 3.5 cm in diameter is obtained .
Air in the intrahepatic bile ducts, without history of surgical biliodigestive
anastomosis or recently performed ERCP is highly suggestive of biliary enteric fistula. In combination with small bowel obstruction, the diagnosis of gallstone ileus was made. Subsequent laboratory laparotomy revealed a gallstone in the terminal
ileum, which was removed. Inspection of the entire small bowel did not disclose any other cause of mechanical small bowel obstruction. The patient recovered uneventfully.
Discussion
Gallstone ileus is a uncommon cause of intestinal obstruction. It causes signs of small bowel obstruction, nausea, vomiting, abdominal distension, and absence of bowel sounds in case of complete obstruction. Intestinal obstruction is seen mostly if the gallstone impacts at the ileocecal junction. In this case, intermittent recurrence of the colics over several days is an important clinical sign. A rare form of gallstone ileus is a gastric outlet obstruction, caused by gallstone, also known as Bouveret's syndrome. Often the diagnosis is delayed because of non specific findings on various examinations. Most radiological imaging modalities do not show the fistula itself. However, presence of air in the intra-hepatic bile ducts is a specific sign of fistula. The stone itself is often demonstrated in one of the terminal ileal loops. Combination of these two findings is highly suggestive for the diagnosis of gallstone ileus. In elderly patients with bowel obstruction, early use of abdominal CT scan should be recommended.
Gallstone ileus has a high morbidity (15-18%) and mortality (17%).
Treatment consists of enterolithotomy and cholecystectomy in a one-stage procedure. Morbidity after enterolithotomy is low. The recurrence rate of gallstone ileus is less than 2%.
Differential Diagnosis List
