S1664 Colonic Obstruction Caused by GB Stone

Abstract

INTRODUCTION: Colonic gallstone ileus is one of the rare causes of intestinal obstruction. These stones usually require surgery although endoscopic removal by different methods; such as extracorporeal lithotripsy, Dormia baskets and polypectomy snares have been described. CASE DESCRIPTION/METHODS: A 69-year-old female with no significant past medical history presented with several days of lower abdominal pain, nausea, vomiting, constipation and abdominal distension. There was no h/o hematemesis, melena or jaundice. She reported no previous colonoscopy. On exam, the patient was found to be in abdominal discomfort. No icterus or pallor was present. Abdominal exam showed distension with tenderness present in the left iliac fossa. Lab results were WBC 19.6, hemoglobin 6.0, platelets 340, total bilirubin 0.9, alkaline phosphatase 84, AST 12, ALT 8, Lactate 8.6. Fecal occult blood was negative. CT abdomen showed significant edema of the proximal colon, pneumobilia with 3.7 cm lamellated calcified lesion resembling a large gallstone present in the distal sigmoid colon resulting in local mechanical obstruction. The patient was diagnosed with gallstone colonic ileus and cholecystocolonic fistula. She underwent attempted removal of stone with the help of rigid sigmoidoscopy and then flexible colonoscopy, but both failed. Finally, she underwent open laparotomy and extended sigmoid colectomy, Hartmann’s procedure and colostomy. The cholecystocolonic fistula was not disturbed. She had a good recovery and was discharged in stable condition after 5 days. At around 6 months, she underwent a biliary scan which showed that the cholecystocolonic fistula had closed spontaneously. She subsequently underwent reversal of the Hartmann procedure and cholecystectomy. Currently she is doing well with no recurrence. DISCUSSION: Large bowel ileus due to gallstone is a rare cause of obstruction. The stone reaches the colon most commonly through cholecystocolonic fistula. The impacted area is usually at a point of pathological narrowing, such as related to diverticular disease, as in our patient. The patient typically presents with abdominal distension, pneumobilia and ectopic stone all of which were present in our patient. CT abdomen is the investigation of choice. Endoscopic Dormia basket removal has been successfully used in the past by authors. But when the stone is too large, surgical removal of the stone may be necessary. The cholecystocolonic fistula also needs to be repaired at a later date which may require surgical re-exploration.Figure 1.: Colonoscopic view showing large Gall Bladder stone in Sigmoid colon.Figure 2.: CT scan abdomen showing the radio-opaque GB stone in the sigmoid colon.