Pancreatic pseudocyst-portal vein fistula: a case treated with EUS-guided cyst-drainage and a review of the literature.

Pancreatic pseudocyst and portal vein thrombosis are common conditions resulting from acute and chronic pancreatitis. However, pancreatic pseudocyst-portal vein fistula (PPVF) is a rare and life-threatening complication. In PPVF patients, drainage or operative therapy is necessary under certain conditions, including communication between the pseudocyst and pancreatic duct, pancreatic duct stricture, pancreatic duct stone, and infection that is difficult to control with antibiotics. We describe the case of a 78-year-old woman who presented with an infected pancreatic pseudocyst invading the portal venous system with obstruction due to thromboembolization. Conservative therapy with antibiotics was insufficient. We, therefore, performed endoscopic ultrasound-guided cyst-drainage (EUS-CD). During EUS-CD, PPVF and pseudocyst-pancreatic duct fistula were confirmed by contrast medium injection. Despite the presence of the pseudocyst-pancreatic duct fistula, the pancreatic duct was not visualized in the pancreatic head, suggesting stricture in the main pancreatic duct. We, therefore, performed endoscopic retrograde pancreatography, which revealed pancreatic stone in the main pancreatic duct. Then, we added a 7-Fr pancreatic stent. She was discharged after 89 days of hospitalization. We reviewed the literature on the management of PPVF formation, and EUS-CD is considered to be a good treatment option for PPVF patients without portal vein patency.