Applied Radiology

CASE SUMMARY

A 79-year-old female was admitted with a one-week history of watery diarrhea, diminished appetite and episodes of coffee ground emesis. Physical examination revealed abdominal distension, lower abdominal tenderness, hypoactive bowel sounds, and melanotic stool. Pertinent laboratory data indicated a slight leukocytosis with a left shift, slight anemia, mild uremia, and an electrolyte imbalance. A gastrointestinal series demonstrated a fistula between the duodenum, a focal extra-enteric barium collection, and the hepatic flexure. Also identified was a large intra-luminal defect obstructing the proximal jejunum, gas and barium in the ascending and transverse colon, and refluxed barium in a non-dilated distal and mid small bowel (figures 1-3).

Diagnosis:

Atypical gallstone ileus with cholecystoduodenal and cholecystocolic fistulas.

Following treatment for dehydration and electrolyte imbalance, an exploratory laparotomy was performed. An enterolithotomy removed a 3 ¥ 3 ¥ 2 cm gallstone. Along with removal of a barely recognizable gallbladder, the fistulas were taken down and closed. An intraoperative cholangiogram did not reveal biliary calculi. The patient tolerated the surgery well and was discharged after a week.

The key to this diagnosis is recognizing the extra-enteric barium between the duodenum and hepatic flexure as a contracted gallbladder whose Aschoff-Rokitansky sinuses and cystic duct are barely identifiable. Obstruction of the duct prevents air or barium from entering the biliary tree. The normal duodenal and colonic mucosa indicated that a diseased gallbladder had fistulized into the adjacent hollow viscera and passed a stone, which eventually obstructed the jejunum. Gas and barium in the transverse colon result from the fistulous short circuit. Opacification of normal distal and mid small bowel is secondary to an incompetent ileocecal-cecal valve.

While unprovable, we postulate that the cholecystoduodenal fistula appears narrow because it is contracted. We also believe another stone could have passed via the cholecystocolic fistula and reached the rectum unimpeded.

Discussion:

Gallstone erosion into the gastrointestinal tract occurs in 3 to 5% of patients with cholelithiasis.1,2,3,4 Gallstone ileus causes 1 to 3% of all mechanical obstructions.1-4 In patients over the age of 60, the incidence rises between 15 and 24%.1 The vast majority of cases are found in elderly, obese females.

Generally, the sequence of events is cystic duct obstruction, cholecystitis, pericholecystitis, abscess formation, fistulization to an adjacent hollow viscus, passage of the stone and, eventually, bowel obstruction. The obstructing stone causes pain, nausea, vomiting, and intestinal distension, necessitating surgery. If the stone directly enters the colon, it may pass asymptomatically to the rectum. In patients with coexistent diverticular disease, benign or malignant stricture, it is very likely to obstruct.5 More commonly, the stone erodes through the postbulbar duodenum. Lodged at this site, it can cause a gastric outlet obstruction. Classically, it will progress through the small bowel and, if greater than 2.5 cm in diameter, obstruct at the ileocecal valve.6

Besides opacifying the fistula and demonstrating the cause and location of the obstruction, the gastrointestinal series is useful in excluding other etiologies. Ruling out granulomatous disease, proximal colonic diverticulitis and primary neoplasms of the transverse colon, duodenum and pancreas makes surgical planning

easier.2,4,7,8

The surgical procedure must be tailored to the individual.1,2,9 Palpation of the entire bowel subsequent to enterotomy and removal of the obstructing stone is necessary to exclude the presence of other enteric stones. Decisions about fistula transection, bowel wall repair, and cholecystectomy must follow. If the inflamed tissues are too friable, the abdomen should be closed and the patient treated medically. Occasionally, the fistulas close spontaneously.1,2

While the absence of jaundice indicates a patent biliary duodenal connection-with or without a normal sphincter of Oddi-cholecystectomy, fistula closure, and bowel wall repair would significantly reduce the possibility of cholangitis and gallbladder carcinoma, which has been found to be more common in patients with cholecystoenteric fistulas.5 At the time of immediate or subsequent elective cholecystectomy, an intraoperative cholangiogram could clarify coexistent choledocholithiasis. If necessary, biliary calculi can be removed during elective endoscopic cholangiography and papillotomy.

References

1. Pangan JC, Estrada R, Rosales, R: Cholecystoduodenocolic fistula with recurrent gallstone ileus. Arch Surg 119:1201-1203, 1984.

2. Doromal NM, Estacio R, Sherman H: Cholecysto-duodeno-colic fistula with gallstone ileus: Report of a case. Dis Colon Rectum 18:702-705, 1975.

3. Hrick H, Vander Molen RL: Duodencolonic fistula with gallstone ileus. Am J Gastroenterol 69:711-715, 1978.

4. Vas Gossum M, Fastrez R, Issa S, et al: Cholecystoduodenocolic fistula and gallstone ileus. Acta Gastroenterol Belg 49:624-627, 1986.

5. Balthazar EJ, Guskin S: Cholecystoenteric fistulas: Significance and radiographic diagnosis. Am J Gastroenterol 65:168-173, 1976.

6. Clavien PA, Richon J, Burgan S, Rohner, A: Gallstone ileus. Br J Surg 77:737-742, 1990.

7. Milson JW, Mackeigan JM: Gallstone obstruction of the colon: Report of two cases and review of management. Dis Colon Rectum 28:367-370, 1985.

8. Balthazar EJ, Schechter LS: Gallstone ileus: The importance of contrast examination in the roentgenographic diagnosis. Am J Roentgenol Radium Ther Nucl Med 125:374-379, 1975.

9. Shocket E, Evans J, Jonas S: Cholecysto-

duodeno-colic fistula with gallstone ileus. Arch Surg 101:523-526, 1970.

Prepared by Alan Wecksell, MD, Polly J. Mirsky, MD, and Angelo Procaccino,

MD, North Shore University Hospital, New York University School of Medicine,

Manhasset, NY.