Portobiliary fistula: unusual complication of wire-guided cannulation during endoscopic retrograde cholangiopancreatography.

used for bile duct cannulation during endoscopic retrograde cholangiopancreatography (ERCP) [1]. Here we present a patient with a WGC-induced portobiliary fistula. A 65-year-old man was admitted to our department for further evaluation of a dilated segment IV bile duct detected on computed tomography (CT). There was no evidence of dilated veins or aberrant vessel development around the pancreatic head on CT. The physical examination and laboratory tests were unremarkable. Duodenoscopy revealed no masses in the ampulla of Vater (●" Fig. 1a). To cannulate the bile duct for further evaluation, WGC using a conventional catheter was attempted. A hard 0.025-inch guide wire was gently and carefully advanced under endoscopic and fluoroscopic guidance (●" Fig. 1b). After three attempts, we assumed that selective bile duct cannulation was achieved because the guide wire advanced smoothly (●" Video 1). The catheter was then inserted over the guide wire with slight resistance near the ampulla of Vater. On cannulation, when we could not aspirate bile or blood, contrast medium was injected through the catheter, which cleared within a few seconds in the direction of the liver (●" Fig. 2). We also recognized subtle blood flow, which we speculated as arising from the posterior superior pancreatoduodenal vein around the pancreatic head (●" Video 2). We realized that the catheter was placed in the portal venous system, and the catheter and guide wire were immediately withdrawn (●" Fig. 1c). Duodenoscopy showed small amounts of blood in the catheter andminor bleeding from the ampulla of Vater (●" Fig. 1d). The patient did not require any treatment for the minor bleeding. Balloon-associated endoscopic retrograde cholangiography (ERC) was carried out 1 week later, but segment IV bile duct was not visualized during this procedure. Cytological analysis of aspirated bile revealed no evidence of malignancy. Based on these radiological and cytological findings, we made the diagnosis of a benign localized biliary stricture as the cause of the dilated segment IV bile duct. We continued careful follow-up with laboratory tests and imaging at regular intervals. Iatrogenic portobiliary fistula is an uncommon complication of biliary drainage, liver biopsy, and surgery, which may result in bleeding, sepsis, portal thrombosis, and air embolism [2]. Cannulation or visualization of the portal vein during ERCP is a rare complication, with an incidence in 1 in 6000–8000 cases [3,4]. This complication during ERCP can result from the laceration of a small portal vein or from direct trauma to the papilla [2]. Serious complications have not been reported. Immediate withdrawal of the tube inserted in the portal vein does not cause serious bleeding [5]. To our knowlPortobiliary fistula: unusual complication of wireguided cannulation during endoscopic retrograde cholangiopancreatography