Delayed Duodenal Perforation Following Gallstone-Induced Afferent Loop Obstruction Due to a Cholecystoduodenal Fistula: A Case Report

Background: Gallstone ileus due to a cholecystoduodenal fistula is a rare complication of chronic cholelithiasis, often leading to small bowel obstruction. While ileal obstruction is common, duodenal impaction and its consequences, including afferent loop syndrome, remain underreported. A significant yet often overlooked risk in these cases is delayed duodenal perforation after gallstone removal. Method: We present a 77-year-old female who developed afferent loop syndrome secondary to a gallstone migrating through a cholecystoduodenal fistula 40 years after distal gastrectomy with Billroth II reconstruction. The gallstone lodged in the third portion of the duodenum, causing afferent loop obstruction, bile stasis, and acute pancreatitis. Emergency laparotomy and gallstone removal were performed to restore the afferent loop flow. Result: However, after two days postoperatively, the patient developed duodenal perforation at the previous site of impaction, requiring a second surgery for repair. Conclusion: This case underscores the need for close postoperative monitoring in gallstone-induced duodenal obstructions due to the risk of delayed perforation and highlights the importance of recognizing cholecystoduodenal fistula as an underlying cause of afferent loop syndrome. Novel Aspect: This case emphasizes the possibility of delayed perforation after a gallstone-induced afferent loop syndrome and recommends intense postoperative care for these patients.