[A Case of Hepatic Encephalopathy Caused by Portal Vein Thrombosis after Surgery for Perihilar Cholangiocarcinoma].

A female in her 70s underwent right hepatectomy with resection of caudate lobe and extrahepatic bile duct for perihilar cholangiocarcinoma(T2aN0M0, Stage Ⅱ: Biliary Cancer Treatment Regulations, 7th edition). On the 4th postoperative day, the patient had impaired consciousness, which worsened to almost coma on the 5th postoperative day. On the same day, a blood test showed high ammonia level, thus the state was thought to be hepatic encephalopathy. Contrast -enhanced CT on the same day showed thrombus from the main trunk of the portal vein to the remnant left branch, narrowing of the lumen of the vessel. Simultaneously, enlarged portosystemic shunt in the pelvic floor due to portal hypertension induced by the thrombosis. Plasmapheresis was performed, and anticoagulation with sodium heparin and antithrombin Ⅲ were started. Then, the portal vein thrombus was reduced, and encephalopathy was improved. She was discharged from the hospital on postoperative day 48. She was treated with edoxaban as an outpatient, and anticoagulation therapy was terminated after a CT scan 6 months after surgery, which confirmed no recurrence of thrombus. She is now alive without recurrence of thrombus or tumor for about 2 years after the surgery.