Teaching Case

An 83-year old male was admitted to our emergency room with a 7-day history of abdominal pain, constipation, nausea and vomiting. The physical exam revealed reduced bowl sounds and diffuse abdominal pain and distention. Blood tests where normal.

Contrast enhanced computed tomography (CECT) of the abdomen showed signs of chronic cholecystitis, pneumobilia and a fistula formation from the gallbladder to the duodenum and choledocal duct. Furthermore the CECT scan showed a localized marked dilatation of the proximal small bowl and a large gallstone (3cm) in the lumen of the distal jejunum. Small amount of free fluid in the upper right quadrant

Gallstone ileus is a rare cause of mechanical bowel obstruction, with a significant mortality (7-30%). [1-3]

Gallstone ileus occurs as a complication of cholelithiasis. A combination of pressure from the gallstone and the inflamed wall of the gallbladder, will result in erosion, creating a cholecystoduodenal fistula tract. After the passing of a gallstone through the fistula, formed between the duodenum and the gallbladder, the stone will lodge thus creating mechanical obstruction. [1,3,4]

In most cases, the stone will lodge near the ileocecal valve (60.5%) as it’s the most narrow segment. However in some cases it will lodge in jejunum (16.1%), stomach (14.2%), the duodenum (3.5%) or the colon (5.7%). Though 40% of cases with a cholecystoduodenal fistula holds multiple stones, they will most likely pass if the stones is less than 2 cm. [1-3]

Clinical Perspective

Patients can present symptoms such as nausea, severe (colicky) abdominal pain and distention, dehydration, tachycardia, hypotension, fever, high-pitched bowel sounds, not passing gas and a history of upper right quadrant pain. The patient might have a history with gallstones (0.3%-0.5% of all gallstone patients results in ileus), is most likely woman (ratio 1:3-7) and above the age of 65 years. [1,2]

Biochemical markers may be unremarkable. If the patient is dehydrated there might be electrolyte derangement. [1,3]

Imaging Perspective

Ideal test and gold standard for gallstone ileus is a contrast-enhanced CT abdomen with a sensitivity of 93%, accuracy of 99% and specificity of 100%. [1,2,3]

Classical signs of gallstone ileus (Riegler’s triad):

1. Intestinal obstruction
2. Pneumobilia
3. Gallstone within the lumen of the intestine

Other signs to look; free fluid, mural gas and portal venous gas, as these will be symptoms of advanced stage and poorer prognosis. Not every stone will calcify (12% - 48.3% in the literature), making it more difficult to find on CT scan, however, the intestines will bulge out proximal and collapse distal to the gallstone.  [2,3]

Outcome

The only effective treatment is surgery.  The stone must be removed by enterolithotomy preferably laparoscopic, although there is some discussion about whether or not a cholecystectomy and fistula repair will beneficial. [1]

Take-Home Message / Teaching Points

Gallstone ileus is rare and occurs primarily in elderly and/or women typically with a history of chronic choleliatis. It presents variable clinical symptoms and no specific biochemical tests making CT abdomen (contrast-enhanced) the gold standard test to provide the diagnosis. An acute operation, enterolithotomy, is the only treatment.