A Case of Mesenteric Venous Thrombosis Caused by Congenital Antithrombin Deficiency

We report a case of mesenteric venous thrombosis caused by congenital antithrombin deficiency. A 30-year-old man was admitted to our hospital with a complaint of severe abdominal pain and vomiting. Contrast-enhanced computed tomography revealed thrombi in the superior mesenteric vein (SMV) and portal vein (PV). In addition, the small intestinal wall was found to be remarkably thickened. We performed emergency laparotomy and discovered congestive necrosis extending 40cm along the ileum. Following bowel resection and subsequent establishment of primary anastomosis, a large thrombus was removed from the incised SMV using a Fogarty catheter. Blood tests revealed antithrombin deficiency, thereby necessitating the administration of heparin and antithrombin concentrate. Although PV was not recanalized postoperatively, the development of collateral vessels prevented the progression of bowel necrosis. The patient is currently under warfarin therapy and requires long-term follow-up and monitoring of portal hypertension.