Risk groups:
(1) hypercoagulable states
(2) intra-abdominal infection or inflammation
(3) vascular stasis (decreased blood flow)
(4) mass lesion interferring with blood flow
(5) vascular injury
Hypercoagulable states:
(1) oral contraceptive therapy
(2) protein S or C deficiency
(3) antithrombin III deficiency
(4) factor V Leiden or prothrombin G20210A
(5) antiphospholipid syndrome
(6) myeloproliferative disorder
(7) paroxysmal nocturnal hemoglobinuria
(8) pregnancy
Intra-abdominal infection or inflammation:
(1) umbilical infection
(2) inflammatory bowel disease
(3) intra-abdominal surgery, including splenectomy
(4) peritonitis (especially spontaneous bacterial peritonitis involving ascites)
(5) pancreatitis
(6) cholangitis
(7) appendicitis
(8) bacteremia
Decreased blood flow:
(1) cirrhosis with portal hypertension
(2) hepatoportal fibrosis
(3) portal hypertension of any cause
Mass lesion interferring with blood flow:
(1) hepatocellular carcinoma
(2) cholangiocarcinoma
(3) metastatic carcinoma to the liver
(4) intravascular tumor spread
(5) congenital anomalies
Vascular injury:
(1) blunt abdominal trauma
(2) catheterization
(3) schistosomiasis
(4) portal vein phlebitis
(5) liver transplantation
(6) infusion of drugs or hyperosmolar glucose into the umbilical vein
(7) exchange transfusion via umbilical vein
