1327 Gallstone Ileus Leading to Small Bowel Perforation: Case Report

Abstract

INTRODUCTION: Gallstone ileus (GI) is a rare but potentially lethal complication of cholelithiasis. It is only responsible for 0.5% of mechanical small bowel obstructions in the general population; but it disproportionately affects the elderly female population, causing roughly 25% of mechanical small bowel obstruction in females over age of 65. Stones must be at least 2-2.5 cm to result in bowel obstruction, typically lodging in the terminal ileum. In rare cases, larger stones can become lodged elsewhere within the bowel, leading to severe complications such as bowel perforation. CASE DESCRIPTION/METHODS: A 77-year-old male with a 6-month history of weight loss presented with non-bloody, nonbilious emesis without abdominal pain three days after an admission for an empyema. Physical exam was notable for a mildly tender abdomen upon presentation without rebound or guarding. He was treated with anti-emetics and IV fluids with mild improvement in symptoms. Liver function panel was significant for alkaline phosphatase of 411 U/L (normal 37-117), while total bilirubin was 0.4 (normal 0.3-1.4). Ultrasound of the abdomen revealed pneumobilia which was previously seen six months earlier on a CT abdomen. Subsequent MRCP revealed a large gallstone in the distal ileum with proximal dilation of the small bowel. Nasogastric decompression was initiated, and patient began passing flatus and had small bowel movements. Later that evening, the he started retching and had severe abdominal pain with rebound tenderness and lactic acidosis (LA 3.1). He became hypotensive and was taken for an emergent laparotomy where a 4 cm gallstone was found impacted in the mid ileum and removed along with 6 cm of perforated small bowel. DISCUSSION: Presenting symptoms of gallstone ileus are often non-specific, frequently leading to a delay in diagnosis and treatment. Although no fistula was identified in this patient by imaging, the most common cause of gallstone ileus in most patients is formation of a cholecystoduodenal fistula. This is thought to result from inflammation associated with cholecystitis along with pressure from a large stone within the gallbladder itself. Nonemergent treatment for larger stones often includes more invasive treatment, such as enterolithotomy or enterotomy with stone extraction. However, as we see in this case, obstructing stones can result in bowel perforation, requiring emergent small bowel resection or even death.