Superior mesenteric vein thrombosis treated with edoxaban

A 58yearold man presented with a 2week history of hypogastric pain. There was no family history of abnormal blood clotting. He showed tenderness in the hypogastrium, but no rebound tenderness or muscular guarding. His vital signs were temperature 36.3°C and regular pulse rate 92 beats/min. Blood examination revealed: Creactive protein, 4.19 mg/dL; Ddimer, 15.6 μg/mL; antithrombin III activity, 70.1% (normal range, 80%130%). Contrastenhanced computed tomography (CT) of the abdomen revealed superior mesenteric vein thrombosis (SMVT) (arrow, Figure 1A, B) and portal vein thrombosis (PVT). Levels for protein C antigen, protein C activity, protein S antigen, and lupus anticoagulant were normal, and no other causes of SMVT such as vasculitis in Beçhet’s disease, inflammatory bowel disease, or abdominal cancer were identified. We therefore diagnosed SMVT caused by antithrombin deficiency. The process of treatment was as follows. Anticoagulant therapy was started with heparin and edoxaban at 60 mg/day on hospital day 1. Heparin was stopped on hospital day 15 because Ddimer had normalized and abdominal symptoms had improved. Contrastenhanced abdominal CT on hospital day 22 revealed that PVT had resolved, whereas slight residual thrombosis persisted in the SMV. The patient was discharged on hospital day 26. Contrastenhanced abdominal CT 25 days later showed disappearance of the SMVT. The patient is still taking edoxaban. SMVT is a rare disorder among the acute abdominal diseases. While specific characteristic symptoms are lacking, intestinal ischemia can result and may require surgery. Because the mortality rate of SMVT is high, starting anticoagulant therapy as soon as possible is important.1 Edoxaban administered once daily after initial treatment with heparin is reportedly noninferior to highquality standard therapy (heparin followed by warfarin) and causes significantly less bleeding in a broad spectrum of patients with venous thromboembolism.2 This is the first report of a successful outcome after SMVT treated conservatively with edoxaban and heparin.