AB139. SOH23ABS_128. Cholecystoduodenal fistula causing gastric outlet obstruction

Background: A 71-year-old female presented with a two-month history of cyclical vomiting, anorexia and associated weight loss. An oseophago-gastro-duodenoscopy (OGD) and a computed tomography (CT) abdomen pelvis (AP) demonstrated a large mural lesion in the body of the stomach. Background medical history includes diabetes mellitus, hypertension, hypothyroidism, atrial fibrillation and gastroesophageal reflux disease. Initial clinical exam and biochemical investigations were unremarkable.

Case Presentation: A repeat CT AP identified a large well marginated mass on the greater curvature of the stomach. A second well marginated hypo-attenuating lesion in the pylorus was also noted causing significant mass effect. Repeat OGD identified residual food and bile content in the stomach. Endophytic extension of the large tumour and mass effect from the extra-luminal lesion in the pylorus was also identified. Intra-operative pictures demonstrate the large tumour at the greater curvature of the stomach, a fluctuant swelling in the proximal duodenum and adhesions between the stomach and gallbladder. After careful dissection an eight-centimetre, thin cholecystoduodenal fistula was identified. The patient underwent a total gastrectomy with a Roux-en-y construction and cholecystectomy. She had an unremarkable post-operative course. Histological analysis confirmed a gastrointestinal stromal tumour and a bile stained fistula tract.

Conclusions: To the best of our knowledge this is only the second case available in the literature where a cholecystoduodenal fistula has created a cyst large enough to cause gastric outlet obstruction. A unique point about our case however is the length and small diameter of the fistula tract without obvious migration of a contributing gallstone.

Keywords: Cholecystoduodenal fistula; cholecystectomy; gastrectomy; gastrointestinal stromal tumour; gastric outlet obstruction