Biliopancreatic fistula with portal vein thrombosis caused by a pancreatic pseudocyst

We encountered a very rare case of biliopancreatic fistula with portal vein thrombosis caused by pancreatic pseudocyst. A 57-year-old man was referred to our hospital because of abdominal pain, obstructive jaundice, and portal vein thrombosis due to acute pancreatitis. Computed tomography showed a 7-cm-diameter pseudocyst around the superior mesenteric vein extending towards the pancreatic head, dilatation of the intrahepatic bile duct, and portal vein thrombosis. Endoscopic retrograde pancreatography revealed a main pancreatic duct with a pseudocyst communicating with the common bile duct. After pancreatic sphincterotomy, a 7-F tube stent was endoscopically placed into the pseudocyst. However, a 6-F nasobiliary tube could not be inserted into the bile duct because the fistula had a tight stenosis. Subsequently, the patient’s abdominal pain improved, the pancreatic cyst disappeared, and the serum amylase level normalized. Two months after the endoscopic retrograde cholangiopancreatography, percutaneous transhepatic biliary drainage was required because the patient’s jaundice became aggravated. Two weeks after the choledochojejunostomy, the patient left the hospital in good condition. A follow-up computed tomography showed cavernous transformation of the portal vein and no pancreatic pseudocyst. The patient remains asymptomatic for 2 years and 7 months after surgery. Biliary drainage may be necessary for biliopancreatic fistula with obstructive jaundice in addition to pancreatic cyst drainage. Biliopancreatic fistula can be treated by endoscopic procedure in some cases; however, surgical treatment should be required in cases that are impossible to insert a biliary stent because of hard stricture.