Gastric outlet obstruction (GOO) results from intrinsic and extrinsic obstruction of the pyloric channel or the duodenum. Here we present a rare case of GOO attributed to dense adhesions between the gallbladder and duodenum secondary to chronic cholecystitis with choledococystoduodenal fistula formation. Previous reports identified elderly females with comorbidities as a predisposing factor; however, our patient was an immunocompetent adult male.

A 43-year-old male with no comorbidities consulted for recurrent epigastric pain, vomiting and weight loss. On contrast enhanced abdominal CT scan, a lamellated cholelithiasis with pneumobilia and an irregular thickening at the proximal duodenum with subsequent GOO was identified. A choledococystoduodenal fistula was considered. Exploratory laparotomy revealed extensive fibrosis and cholecystitis with dense adhesions to surrounding structures. Dissection revealed a gallstone impacted in and adherent to the wall of the gallbladder and a fistula opening into the duodenum. However, there was no definite evidence of impacted gallstone in the duodenum. The dense adhesions secondary to chronic cholecystitis caused duodenal narrowing and subsequent GOO. He eventually underwent antrectomy, pancreatic sparing, total duodenectomy, cholecystectomy, with loop gastrojejunostomy, cholecystojejunostomy and pancreaticojejunostomy. Biopsy specimens taken were negative for malignancy. He was discharged subsequently. However, he was readmitted after five months due to acute abdomen secondary to small bowel rupture, likely from a marginal ulcer.

This case highlights that preoperative and intraoperative differential diagnosis of GOO is a challenge. Chronic calculous cholecystitis through severe inflammation can present as a rare cause of GOO. Optimal treasaFtment plan should take into consideration the underlying etiology of the GOO.