Portal hypertension (also Portal hypertension, portal hypertension ) refers to the increase in portal venous pressure above the normal range (3-6 mmHg). Gastroesophageal varices are likely to emerge only > 12 mmHg from a pressure.
Etiology and pathogenesis
The portal vein is composed of the product of the transhepatic blood flow and the flow resistance in its current path. Both an increase in resistance and increased portal blood flow therefore have an impact on the portal pressure.
Increased synthesis or release of vasodilator substances such as nitric oxide, substance P or calcitonin gene - related peptide in the arterioles of the viscera lead to a hyperdynamic circulation and thus to increased blood flow, which means an increased portal pressure related.
The main trigger of portal hypertension is cirrhosis of the liver; in the following table are the main trigger summarized, sorted by their localization in the current path.
- Ballooning of hepatocytes
- Formation of regenerative nodules
- Capillarization of the sinusoids with obstruction of the crossing of the plasma in the space of Disse
- Compression of the sinusoids
- Interruption of portal venous sinusoidal flow through connective tissue
- Training of arterioportalen shunts
- Compression of the sinusoids by contractile myofibroblasts from stellate cells
- Rarefaction and reduction of fenestrae
Consequences of portal hypertension
- Proximal stomach - so-called fundal
- Distal esophagus ( submucous and perioesophageal ) - so-called esophageal varices
- Submucosa rectum
- Kidney ( spontaneous splenorenaler shunt)
- Medusae veins of the abdominal wall as well as the reopening of the umbilical vein ( umbilical vein ) as so-called caput
Cruveilhier -Baumgarten syndrome
The Cruveilhier -Baumgarten syndrome (CBS ) is a portal hypertension due to liver cirrhosis, associated with bypass blood flow through the veins of the abdominal wall around the navel ( close themselves in a healthy person after birth). By means of ultrasonographic examination, the CBS can be detected with liver cirrhosis in 9-26 % of patients.