Portal vein thrombosis is quite common in patients with cirrhosis, but is also seen in patients without significant cirrhosis. Risk factors for portal vein thrombosis include both local and systemic categories. Local factors account for approximately 70% of portal vein thrombosis. These local factors include: 1. Cancer: any abdominal tumor may cause portal vein thrombosis. 2. Local inflammatory lesions: (1) neonatal umbilicitis, umbilical vein cannulation; (2) diverticulitis, appendicitis; (3) pancreatitis; (4) duodenal ulcer; (5) cholecystitis; (6) tuberculous lymphadenitis; (7) Crohn’s disease, ulcerative colitis; (8) cytomegalovirus hepatitis and so on. 3.Portal venous system injury: (1) splenectomy; (2) colon resection, gastrectomy; (3) liver transplantation; (4) abdominal injuries; (5) portal – vena cava system surgical shunt, TIPS; (6) medically induced injuries, such as abdominal mass fine needle puncture examination and so on. Cirrhosis: (1) stable liver function combined with predisposing factors, such as splenectomy, surgical porto-caval shunt, TIPS failure, thrombosis tendency and so on. (2) Progressive cirrhosis without clear triggers. Systemic factors lead to portal vein thrombosis accounted for about 30%, these factors include: 1, hereditary: (1) Leiden Ⅴ factor variant: (2) factor II (prothrombin) variant; (3) protein C deficiency; (4) protein S deficiency; (5) antithrombin deficiency and so on. Acquired: (1) bone marrow and extramedullary proliferation abnormalities; (2) antiphospholipid syndrome; (3) paroxysmal nocturnal hemoglobinuria; (4) oral contraceptives: (5) pregnancy or postpartum; (6) homocysteinemia; (7) malignant tumors and so on. Portal vein thrombosis is divided into acute portal vein thrombosis and chronic portal vein thrombosis according to the urgency of onset. Acute portal vein thrombosis is mainly a manifestation of intestinal stasis and ischemia, including abdominal pain, abdominal distension, diarrhea, bloody stools, nausea, vomiting, poor appetite, fever, lactic acidosis, splenomegaly and sepsis. If venous reflux is not resolved quickly, intestinal perforation, peritonitis, shock, and multiple organ failure to the point of death can occur. The main manifestations of chronic portal vein thrombosis include: esophageal and fundic varices, gastrointestinal bleeding, open subcutaneous collateral veins, splenomegaly, pancytopenia (hypersplenism), and so on. The treatment of portal vein thrombosis includes: anticoagulation, thrombolysis, bridging and shunting of blood vessels on both sides of the thrombus, and abdominal multivisceral transplantation or modified abdominal multivisceral transplantation for extensive thrombus and refractory, life-threatening gastrointestinal bleeding.