Gallstone ileus

Clinical History

A 53-year-old woman complaining of recurrent abdominal pain over two months presented to the emergency department because of worsening symptoms and nausea. Physical examination revealed a tender abdomen without active bowel sounds. Laboratory tests showed mild leukocytosis.

Imaging Findings

Computed tomography (CT) showed distal small bowel occlusion with pneumobilia and a fistula tract between the gallbladder and the upper duodenum. Just above the level of the transitional zone in the proximal ileum, coronal reconstruction showed an ovoid, hypodense and well delimited intraluminal element.

Discussion

A. Gallstone ileus is a mechanical obstruction of the gastrointestinal tract by an ectopic biliary calculus. It accounts for 1-3% of all intestinal obstructions [3] and is associated with a high mortality due to often delayed diagnosis and coexisting medical conditions [1]. The average age of patients with gallstone ileus is 65-75 years and women are more often affected than men (4-9:1) [3]. In less than 1% of chronic cholecystitis cases, mostly when big bladder calculi (>2.5 cm) are involved, they may erode the gallbladder wall and cause a fistula connecting to the gastrointestinal tract, usually the duodenum [3, 5].

B. Patients experience the usual symptoms of chronic cholecystitis followed by recurrent acute colics of abdominal pain with nausea and vomiting because of the gallstone temporarily occluding the gastrointestinal lumen in one spot before moving on to reocclude it elsewhere [1]. When the gallstone occludes already the distal stomach or the proximal duodenum, it is called the Bouveret syndrome [4], but this site of occlusion remains rare. Sometimes patients present with haematemesis because the gallstone may erode the duodenal wall. The most common permanent occlusion site is at Bauhin's valve (60%), followed by the proximal ileon (25% of cases) [1, 6].

C. The classic radiographic triad of finding in gallstone ileus is called the "Rigler triad" and includes: small bowel obstruction, pneumobilia, and an ectopic gallstone [1]. These three signs are rarely found simultanously [2], but the combination of two is considered pathognomic of gallstone ileus and is encountered in 40-50% of cases [1]. Most of the time, the diagnosis is facilitated by the calcified character of the gallstone. In few instances, as is the case in our patient, a non calcified gallstone causes the occlusion, underlying the necessity of attentive lecture of the CT. Patient history is important to exclude other causes of pneumobilia like preceeding biliary surgery [1].

D. Gallstone ileus requires emergency laparotomy and removal of the impacted stone. Since many patients have several biliary calculi, it is important that the surgeon palpates the entire bowel intraoperatively, after the gallstone has been removed, to avoid repeating operations for other obstruction sites [1]. Surgeons may choose not to close the bilio-digestive fistula as it tends to close spontaeously once the gallstone has passed.

Differential Diagnosis List

Final Diagnosis

Gallstone ileus

URL:	https://www.eurorad.org/case/10196
DOI:	10.1594/EURORAD/CASE.10196
ISSN:	1563-4086