What is causing this patient's intestinal obstruction?

Prepared by Darin F. Doumite, Medical Student IV, and Brian Beeman, MD, General Surgery Chief Resident, Synergy Medical Education Alliance/St. Matthew's University, Saginaw, MI; and Dennis Boysen, MD, General Surgery Program Director, Synergy Medical Education Alliance, Associate Professor of General Surgery, Michigan State University, Saginaw, MI

CASE REPORT

A 62-year-old woman presented to the hospital reporting a 1-week history of nausea, mild abdominal pain, constipation, and emesis, which was bilious and nonbloody. Her abdominal pain, primarily in the epigastric and right upper quadrant, was dull and nonradiating. She had an episode of diarrhea 7 days earlier, followed by constipation, and had not passed flatus for 1 to 2 days. The patient's medical history was significant for diabetes, which was controlled through diet.

All the patient's vital signs were within normal limits. Her abdomen was soft and mildly distended, with tenderness in the epigastric area and the right upper and lower quadrants. Palpation elicited no rebound or guarding and was negative for Murphy's sign. No fluid thrill was noted and bowel sounds were hypoactive on auscultation. No hernias were appreciated, and she was anicteric. Laboratory tests revealed the following: white blood cell count, 16,100/mm³; neutrophils, 0.851; hemoglobin, 15 g/dL; total bilirubin, 22.23 μmol/L; aspartate aminotransferase, 20 U/L; alkaline phosphatase, 37 U/L; amylase, 45; and lipase 51 U/L.

An abdominal radiograph and abdominal and pelvic computed tomography scans were obtained

What is causing this patient's intestinal obstruction?

• Small bowel neoplasm
• Foreign body perforation
• Gallstone ileus
• Hernia

Answer

DIAGNOSIS: Gallstone ileus

The abdominal radiograph shows dilated loops of small bowel, air fluid levels, and a large amount of stool in the colon. The computed tomography (CT) scans demonstrate a thickened structure in the gallbladder fossa containing air and contrast; other findings include pneumobilia, a cholecystoduodenal fistula, and a sizeable gallstone in the distal jejunum, with dilated loops of bowel proximal to this point. Our diagnosis was gallstone ileus resulting in jejunal obstruction.

During open enterolithotomy, a 4.5 x 3.5 x 2.0 cm gallstone was removed from the jejunum (Figure). The enterotomy was repaired transversely, and the gallbladder, biliary tract, and cholecystoduodenal fistula were left undisturbed. The patient suffered postoperative ileus, requiring 3 days of nasogastric decompression. She was discharged on postoperative day 6 and has had no further symptoms.

Figure—Intraoperative photograph of the open enterolithotomy showing a large gallstone in the distal jejunum (A) and a pathology image of the gallstone, which measured 4.5 x 3.5 x 2 cm (inset).

DISCUSSION

Gallstone ileus is a rare cause of intestinal obstruction and is most common in women aged 74 to 80 years.^1,2 It accounts for less than 4% of all bowel obstructions and more than 25% of nonstrangulated bowel obstructions in patients older than 65 years, and its mortality rate is 15% to 18%.³ Patients often present with abdominal pain and vomiting, but no signs or symptoms specific to gallbladder or intestinal disease. Less than 25% of patients noted biliary colic in the year prior to diagnosis.⁴

Obstruction occurs when a gallstone 2.5 cm or larger passes through a cholecystoenteric fistula into the intestinal lumen. Fistulas form during repeated attacks of cholecystitis, and the most common are cholecystoduodenal, followed by cholecystocolonic, cholecystogastric, and choledochoduodenal. More than 80% of gallstones that migrate to the bowel are excreted,⁵ but a gallstone can cause obstruction anywhere along the gastrointestinal tract from the duodenum to the colon. The most common site of intestinal obstruction is the distal ileum near the ileocecal valve, which is the narrowest section of the small bowel.

When gallstone ileus is suspected, abdominal radiographs should be examined for Rigler's triad of pneumobilia, intestinal obstruction, and aberrantly located gallstones, although only 40% of cases demonstrate such findings.³ CT scanning has increased the rate of preoperative diagnosis and should be used when abdominal radiographs or ultrasonography findings are inconclusive. Only 13% to 48% cases of gallstone ileus are diagnosed preoperatively,⁶ and diagnosis and treatment are frequently delayed, with an average of 2 to 5 days from admission to surgery.⁵

Gallstone ileus is a surgical emergency. Enterolithotomy, with a mortality rate of 11.7%, is the gold standard of treatment. Surgical-site infections are the most common cause of morbidity. Some argue that laparoscopic enterolithotomy reduces this risk and should be considered, depending on the patient's situation and the surgeon's experience performing the procedure.⁷

Management of the cholecystoenteric fistula is controversial. Because patients with gallstone ileus are usually elderly and high-risk with concomitant medical disease, the literature generally supports enterolithotomy alone, which is associated with shorter surgical times and a lower mortality rate when compared with one- and two-stage procedures. These operations are far more complex, and most authors agree they should be reserved for low-risk patients, when practical, or in cases of gallbladder necrosis and empyema.⁵

DISCLOSURE

The authors have no relationship with any commercial entity that might represent a conflict of interest with the content of this article and attest that the data meet the requirements for informed consent and for the Institutional Review Boards.

REFERENCES

1. Reimann AJ, Yeh BM, Breiman RS, et al. Atypical cases of gallstone ileus evaluated with multidetector computed tomography. J Comput Assist Tomogr. 2004;28:523-527.
2. G?rleyik G, G?rleyik E. Gallstone ileus: demographic and clinical criteria supporting preoperative diagnosis. Ulus Travma Derg. 2001;7:32-34.
3. Wig JD, Suri S. A good computed tomography in gallstone ileus. J Clin Gastroenterol. 1997;24:58-59.
4. Anagnostopoulos GK, Sakorafas G, Kolettis T, et al. A case of gallstone ileus with an unusual impaction site and spontaneous evacuation. J Postgrad Med. 2004;50:55-56.
5. Lobo DN, Jobling JC, Balfour TW. Gallstone ileus: diagnostic pitfalls and therapeutic successes. J Clin Gastroenterol. 2000;30:72-76.
6. Shenoy VN, Limbekar S, Long PB, et al. Relief of small bowel obstruction following colonoscopy in a case of gallstone ileus. J Clin Gastroenterol. 2000;30:326-328.
7. Ferraina P, Gancedo MC, Elli F, et al. Video-assisted laparoscopic enterolithotomy: new technique in the surgical management of gallstone ileus. Surg Laparosc Endosc Percutan Tech. 2003;13:83-87.