Acute portal vein thrombosis due to chronic relapsing pancreatitis: a fistula between a pancreatic pseudocyst and the splenic vein

Portal vein thrombosis (PVT) is a relatively common complication in patients with liver cirrhosis, but several other causes might play an important role in PVT pathogenesis. We present a case of alcoholic chronic pancreatitis complicated by acute extensive PVT. The patient was managed conservatively with danaparoid sodium at first, but the thrombosis gradually extended. We then tried radiological intervention using the direct transhepatic and transjugular intrahepatic postsystemic shunt approaches. Although we were able to successfully catheterize the percutaneous transhepatic portal vein (PTP), we could not achieve recanalization of the portal vein. Therefore, PTP catheterization and systemic intravenous infusion of urokinase and heparin was performed to prevent further progression of the thrombosis and cavernous transformation was finally achieved. Computed tomography (CT) and magnetic resonance cholangiopancreatography revealed a pancreatic stone which had possibly induced dilatation of the tail duct and formation of a pancreatic pseudocyst and caused intractable pancreatitis. We performed endoscopic retrograde cholangiopancreatography and placed a stent in the pancreatic duct, which completely cured the pancreatitis. Retrospectively, the previous CT with curved multi-planar reconstruction was reviewed and a fistula was detected between the pancreatic pseudocyst and splenic vein. We concluded that the etiology of the PVT was not only inflammatory extension from pancreatitis but also a fistula between the pancreatic duct and the splenic vein.