A Case of Portal Vein Thrombosis due to Protein S Deficiency which Avoided Intestinal Resection

Abstract

A 69-year-old man was admitted to our hospital with acute-onset abdominal pain. Abdominal computed tomography showed complete occlusion of the portal vein (PV) and superior mesenteric vein (SMV) due to thrombus, and poor contrast filling in some of the small intestine. The patient was considered to have an intestinal infarction secondary to SMV/PV thrombosis. Exploratory laparotomy and thrombectomy were performed. Postoperative anticoagulant therapy improved intestinal blood flow and caused thrombus regression. Protein S (PS) activity level was reduced at 17%, suggesting that PS deficiency contributed to the thrombus formation. SMV/PVT caused by PS deficiency is extremely rare and is considered to have a high case fatality rate because it causes intestinal necrosis. In our case, intestinal resection was avoided by early thrombectomy, and the outcome was considered favorable.