Communication between the intra-abdominal splanchnic circulation and the systemic venous circulation
portal hypertension induces the formation of collateral bypass channels wherever the portal and systemic systems communicate
Portal blood flow is thereby diverted through the stomach veins into the plexus of esophageal subepithelial and submucosal veins, thence into the azygos veins and the superior vena cava
often it is eroded and inflamed because of its exposed position, further weakening the tissue support of the dilated veins
Among persons with advanced cirrhosis of the liver, half the deaths result from rupture of a varix, either as a direct consequence of the hemorrhage or from the hepatic coma triggered by the hemorrhage
Bleeding from concomitant gastritis, peptic ulcer, or esophageal laceration accounts for most of the remainder.
hemorrhage subsides spontaneously in only 50% of cases; endoscopic injection of thrombotic agents (sclerotherapy) or balloon tamponade is often required.
When varices bleed, 20% to 30% of patients die during the first episode.
Among those who survive, rebleeding occurs in approximately 70% within 1 year