The causes of portal vein thrombosis are complex, mainly inflammatory, neoplastic, coagulation dysfunction, post-abdominal surgery, traumatic and of unknown origin. 25%-30% of adult portal vein thrombosis cases are secondary to cirrhosis. In infants and children, portal vein thrombosis is mostly secondary to congenital portal atresia, umbilical vein sepsis, appendicitis, etc. PT can be classified as primary or secondary health search. Primary PT is mostly related to blood hypercoagulability. Foreign reports of 372 patients with secondary mesenteric vein thrombosis found that peripheral phlebitis, inflammatory diseases of the abdominal cavity, major abdominal surgery and portal hypertension were the main factors and were common after splenectomy. Local factors account for 40% of the risk factors for PT formation The presence of local factors promotes the formation of portal vein thrombosis, and these local factors are divided into four main categories: local foci of infection, injury to the portal venous system, abdominal tumors and cirrhosis Clinically, cirrhosis is the most frequent cause of PT. Some scholars believe that at least 1/3 of PT patients firecan.com are the result of a combination of risk factors. 1, portal hypertension Mostly due to various etiologies of cirrhosis and congestive splenomegaly. It is mainly due to elevated portal vein pressure, resulting in a decrease in hepatic blood flow in the portal vein and its branches and a slowing of blood flow velocity resulting in eddy flow and platelet accumulation to form a thrombus. 2.Abdominal infection is caused by the bacteria of infectious intestinal lesions entering the portal system, such as neonatal umbilitis, umbilical vein sepsis. Common ones in adults are acute appendicitis, pancreatitis, cholecystitis, perforation of cavity organs, small intestine inflammatory lesions abdominopelvic abscess and postoperative abdominal infection. 3, abdominal surgery and trauma Various abdominal surgeries can lead to thrombosis of the portal venous system, especially after splenectomy, which is most common and may be related to postoperative thrombocytosis and increased blood viscosity. Reduced portal venous blood flow after splenectomy and decreased portal venous pressure accelerate thrombosis. In addition, the slow blood flow in the dilated splenic vein after surgery contributes to the formation of splenic vein thrombosis in a hypercoagulable state. 4, blood in a hypercoagulable state abdominal tumors firecan.com, especially those of the colon and pancreas, are often accompanied by a hypercoagulable state of the portal venous system, which can lead to thrombosis. In recent years, it has also been found that hereditary coagulation disorders are also involved in the formation of portal vein thrombosis, including protein C, protein S and antithrombin defects. 5.Tumor and other compression of portal vein Tumor (such as pancreatic tumor, hepatocellular carcinoma) compression, intestinal torsion and other causes of portal vein system blood flow obstruction, resulting in portal vein thrombosis. 6.Other causes include primary small vein sclerosis, spread of splenic vein or mesenteric vein thrombosis, some patients have long-term history of taking contraceptives, and rare factors include various kinds of congestive heart failure, erythrocytosis, etc. 7.Primary portal vein thrombosis A small number of extrahepatic portal vein embolism has no clear etiology. There may be a history of deep vein thrombosis or wandering thrombophlebitis in the extremities.