Q1: What abnormalities are seen on the plain film (fig 1; see p 709) and computed tomogram (fig 2; see p 709) of the abdomen?

Plain film shows air in the biliary tract and gall bladder, dilated loops of small intestine, and multiple air-fluid levels in small bowel loops. The computed tomogram shows large gall stone impacted in jejunum and multiple air-fluid levels in small intestine.

Q2: What is the diagnosis?

Gall stone ileus.

Q3: What other variants of this disease are known to occur?

The complications of cholelithiasis are shown in table 1. Gall stones can get impacted at various sites, the commonest being the ileocaecal junction. The other described sites of gall stone impaction with in the bowel are the jejunum, stomach, colon, duodenum, and pylorus (Bouveret’s syndrome).

GALL STONE ILEUS

Gall stone ileus is a mechanical bowel obstruction caused by passage of gall stones from the biliary system through a biliary-enteric fistula with impaction within lumen of the bowel.

It is an uncommon complication of biliary stone disease, accounting for only 2% of all cases of intestinal obstruction. Gall stone ileus is, however, more common in the elderly and accounts for approximately 25% of all cases of intestinal obstruction in patients over 65 years of age.¹

The gall stone that causes ileus is usually more than 2.5 cm in diameter. Multiple stones are present in 3%–15% of cases.^1,2

Gall stones usually enter the intestinal lumen through a cholecystoenteric fistula, and 68% of these are between the gall bladder and the duodenum. A history of prior biliary tract disease is present in almost 50%–60% of patients with gall stone ileus.²

The most frequent site of stone impaction is the ileum (>60% of cases), as it is the narrowest part of the bowel. Other sites of obstruction are the jejunum (16%), stomach (14%), colon (4%), and duodenum (3%). Gastric outlet obstruction, or Bouveret’s syndrome, occurs when the gall stone lodges in the duodenal bulb (1%).¹

Clinical features

Usually abdominal pain is a prominent symptom, and associated illnesses such as diabetes and cardiovascular disease are common. It causes signs of small bowel obstruction like nausea, vomiting, abdominal distension, and absence of bowel sounds in cases of complete obstruction. Signs of intestinal obstruction are seen mostly if the gall stone impacts at the ileocaecal junction. However, the characteristic features of intestinal obstruction are found in only 50% to 70% of patients.^2,3 This may be because as the gall stone “tumbles” through the gastrointestinal tract, it impacts and disimpacts, producing intermittent mechanical obstruction.

Investigations

The diagnosis of gall stone ileus is often difficult to make.

The classic radiographic signs of gall stone ileus on abdominal plain film are pneumobilia, mechanical small bowel obstruction, and the presence of a new stone or changed position of a previously identified stone, known as Rigler’s triad.¹

Ultrasound reveals diseased gall bladder, whether there is gas in it or in the bile ducts or both, and fluid filled bowels that can be followed to the stone in the intestine. The presence of stones in the gall bladder will modify the planned operative procedure in the treatment of gall stone ileus.

The characteristic features of Rigler’s triad are easily identified on computed tomography even if abdominal plain film is subtle. Even if abdominal radiography reveals the characteristic signs of small bowel obstruction, computed tomography is useful for excluding complications (for example, strangulation). When unexplained bowel obstruction is present, particularly in the elderly, the early use of computed tomography is strongly recommended.

Endoscopy has been the main diagnostic procedure for Bouveret’s syndrome. The diagnosis was made endoscopically in more than 90% of the cases.⁴

Treatment

Gall stone ileus is a serious geriatric surgical emergency. It has a high morbidity (15%–18%) and mortality (17%).

The management of gall stone ileus is controversial. The choice is between performing simple enterolithotomy or a single stage procedure involving enterolithotomy, cholecystectomy, and fistula closure. Current reports favour enterolithotomy only, with definitive biliary surgery performed later if symptoms persist. Advocates of the combined procedure contend that it prevents recurrent gall stone ileus, cholangitis, and gall bladder carcinoma complications that occur in nearly one third of patients who undergo enterolithotomy only. Simple enterolithotomy carries a mortality of 11.7% compared with 16.9% for one stage procedure. The most common source of operative morbidity is wound infection, occurring in 30%–40% of cases.^5,6

In duodenal stone impaction extracorporeal shock wave lithotripsy is successful in fragmenting the stone. Endoscopic stone removal is especially indicated in poor risk patients. A dislodged impacted stone can migrate distally and cause small bowel mechanical obstruction that might require urgent enterolithotomy.⁴

The recurrence rate of gall stone ileus is less than 2%.²

Final diagnosis

Gall stone ileus.