[Pathologic-anatomic reflections on portal hypertension (author's transl)].

Portal hypertension is defined as an increase of the portal venous pressure over 20 cm H2O or 7 mm Hg, respectively. It may be induced by different types of portal venous stenosis or obstruction, primarily by cirrhosis and fibrosis of the liver and, less frequent by posthepatic disorders such as the Budd-Chiari-syndrome or congestive heart failure. Portal hypertension is followed by ectasia and phlebosclerosis of the portal vein, by splenomegaly, ascites and by various types of collateral circulation. Among these, oesophageal varices, are most important since they often lead to acute upper gastrointestinal haemorrhage, the major complication of portal hypertension. Bleeding from oesophaeal varices is essentially based on atrophy of the squamous epithelium, caused by ischemia from local hypoxia and venous stasis. Portal hypertension and the frequently compromised blood clotting mechanism due to reduced synthesis of clotting factors in the liver aggravate the bleeding. Atrophy of the esophageal mucosa presents an area of decreased resistance likely to ulcerate with easy erosion of the varices--usually lying very superficially--; with mechanical irritation by food or peptic erosion from gastroesophageal reflux being frequent inducers of hemorrhage.