GI is a mechanical obstruction caused by one or more large gallstone within the bowel. It accounts for 1–4% of all cases of mechanical intestinal obstruction, mainly in the elderly, with a female to male ratio of 3.5–6.0:1.1–3
Recurrent inflammations due to gallstones determine the onset of bilio-enteric fistula.4,6
The most common fistulas are between the gallbladder and duodenum (60%–86%), ileum and colon, while a fistulous tract with stomach is very rare.
The terminal ileum and the ileocecal valve are the most frequent sites of impaction (50%–75%), followed by proximal ileum and jejunum (20%–40%), stomach, duodenum (10%). The impaction of a gallstone in the colon, as occurred in our experience, represents a rare event.4,7
Clinical presentation of GI, due to the intestinal obstruction, depends on the site of impaction and it may be acute, intermittent or chronic.5
The most common symptoms include nausea, vomiting and epigastric pain.
Diagnosis of GI is difficult, and in about 50% of cases is intraoperative. Diagnostic accuracy of plain abdominal film is about 50%, although only 10% of gallstones are sufficiently calcified to be radiographically visualized.10
Classic findings include: pneumobilia, intestinal obstruction and aberrant gallstone location (Rigler's triad). The presence of at least two of these three signs is considered pathognomonic and is described in 40%–50% of cases.7
Ultrasound, associated to a plain abdominal film, can be used to confirm the pre-operative diagnosis, showing cholelithiasis, and in some cases also fistula may be suspected. 8,9
Regarding bilio-enteric fistula, its location, the number and size of stones, CT scan may improve diagnostic accuracy.7,14,16
Moreover contrast enhanced abdominal CT scan is reported to have the highest specificity and sensitivity in diagnosing G.I.
Surgical treatment is still subject of research. Current operative options are: (1) enterolithotomy alone; (2) enterolithotomy with cholecystectomy performed later (two-stage surgery); (3) enterolithotomy, cholecystectomy and fistula repair (one-stage surgery).
Several factors should be considered in the choice of the most appropriate surgical approach, related to the patient and other diseases (biliary-enteric fistula).
The duration of the bowel obstuction is the most important prognostic factor. In patients with a diagnostic delay, the main goal of the treatment should be the prompt relief of the intestinal obstruction by enterolithotomy alone.
Patient's age and comorbidity may contraindicate a one-stage surgery. Thereby, preoperative stabilization is essential, with a special attention to the fluid and electrolytes balance and the management of comorbid conditions. Furthermore, co-morbidity is associated with an increased risk of postoperative complications (enteric or biliary leakage after the closure of the fistula).
Enterolithotomy alone remains the most common operative method in the majority of cases, because of its low incidence of complications. A spontaneous closure of the fistulous tract is observed in more than 50% of cases.7,10,17
Recently, laparoscopy assisted enterolithotomy and endoscopic removal are becoming the preferred approaches for the treatment of GI.11–13,16
Delayed diagnosis, concomitant comorbidity and advanced age are the causes of an high mortality rate (7.5–15%).1–3
Several studies have shown that the average period of time between the onset of symptomatology and the time of admission goes from 1 to 8 days7,14,15
, while time range between admission and operation is 3–4.5 days.5,7