Portal Hypertension: Causes

Pathogenesis (development of disease)

The portal vein (vena portae) collects blood from the veins of the unpaired abdominal organs (gastrointestinal tract/gastrointestinal tract and spleen) and delivers it to the liver. There, among other things, the elimination of toxins takes place, most of which are metabolized (metabolized) in the liver. The most common cause of portal hypertension is a restriction of the flow path of portal blood, as occurs in the course of liver cirrhosis (liver shrinkage) (80% of cases). Here, the liver structure is irreversibly (irreversibly) destroyed by a connective tissue remodeling of the liver parenchyma (liver tissue). The increase in hepatic vascular resistance and the increase in portal venous blood flow lead to portal hypertension. Anastomoses (bypasses) develop, from the portal to the caval venous system (portocaval anastomoses), one of which leads to the esophagus (food pipe) (porto-gastroesophageal collaterals). The collaterals (collateral branches of veins) receive increased blood flow to equalize pressure. They dilate (widen) and esophageal and/or fundic varices form. Other collateral veins include:

  • Umbilical collaterals – venous connection between umbilical veins and epigastric veins.
    • Complication: “caput medusae” (visible collateral veins on the abdominal skin).
  • Mesenterico-hemorrhoidal collaterals.
  • Gastro-phreno-(supra)renal collaterals.
    • In the region of the spleen and kidneys

Etiology (causes)

Behavioral causes

Disease-related causes

  • Prehepatic (obstruction (narrowing) is located before the liver) – approximately 15-25% of affected individuals suffer from this form.
    • Idiopathic (with no apparent cause).
    • Splenic vein thrombosis
    • Portal vein thrombosis (PVT) (common).
  • Intrahepatic (obstruction is within the liver) – approximately 70-80% of affected individuals suffer from this form
    • Presinusoidal (sinusoids = capillary area of the liver).
      • Schistosomiasis – worm disease (tropical infectious disease) caused by trematodes (sucking worms) of the genus Schistosoma (couple flukes).
      • Hepatoportal sclerosis (rare disease with sclerosis (calcification) of the intrahepatic (“located inside the liver”) portal veins).
      • Congenital (congenital) fibrosis (abnormal proliferation of connective tissue).
      • Myeloproliferative disorders (group of malignant (malignant) hematological (affecting the blood) diseases).
      • Primary biliary cholangitis (PBC, synonyms: non-purulent destructive cholangitis; formerly primary biliary cirrhosis) – relatively rare autoimmune disease of the liver (affects women in about 90% of cases); begins primarily biliary, i.e. at the intra- and extrahepatic (“inside and outside the liver”) bile ducts, which are destroyed by inflammation (= chronic non-purulent destructive cholangitis). In the longer course, the inflammation spreads to the entire liver tissue and eventually leads to scarring and even cirrhosis; detection of antimitochondrial antibodies (AMA); PBC is often associated with autoimmune diseases (autoimmune thyroiditis, polymyositis, systemic lupus erythematosus (SLE), progressive systemic sclerosis, rheumatoid arthritis); Associated with ulcerative colitis (inflammatory bowel disease) in 80% of cases; long-term risk of cholangiocellular carcinoma (CCC; bile duct carcinoma, bile duct cancer) is 7-15% (common).
    • Sinusoidal
    • Postsinusoidal
      • Hepatic vein occlusion syndrome (veno-occlusive disorders (VOD))
      • Mostly toxic damage from cytostatics (drugs used in cancer).
  • Posthepatic (obstruction is posterior to the liver) – approximately 1% of affected individuals suffer from this form
    • Budd-Chiari syndrome (thrombotic occlusion of the hepatic veins) (rare).
    • Pericarditis constrictiva (thickening and calcification of the pericardium/”armored heart“).
    • Right heart failure (right heart weakness) (common).