esophageal vein

The esophageal vein is a vein that drains blood from the esophagus and empties primarily into the azygos vein, part of the systemic venous system. Multiple esophageal veins exist along the length of the esophagus.

The esophageal veins in the upper and middle esophagus drain into the azygos vein. In the lower esophagus, esophageal veins also communicate with the left gastric (coronary) vein, which is part of the portal venous system, creating an important portosystemic anastomosis.

In portal hypertension, increased pressure in the portal venous system causes blood to be diverted through portosystemic anastomoses. At the lower esophagus, portal blood flows backward through the left gastric vein into the esophageal venous plexus, causing esophageal varices, which are dilated, tortuous veins at risk of life-threatening rupture and bleeding.

Esophageal varices develop when the submucosal esophageal venous plexus becomes engorged due to portal hypertension. The esophageal veins, which normally drain into the azygos system, become dilated and varicose as they accept increased portal blood flow from the left gastric vein.

The esophagus has segmental venous drainage. The cervical esophagus drains into the inferior thyroid veins, the thoracic esophagus into the azygos and hemiazygos veins, and the abdominal esophagus into both the left gastric (portal) and azygos (systemic) veins, making the distal esophagus a key site of portosystemic communication.