Left gastric vein
The left gastric vein is a vein carrying deoxygenated blood that derives from tributaries draining both surfaces of the stomach; it runs from right to left along the lesser curvature of the stomach, between the two layers of the lesser omentum, to the esophageal opening of the stomach, where it receives some esophageal veins.
It then turns backward and passes from left to right behind the omental bursa and drains into the portal vein. Thus, it acts as collaterals between the portal veins and the systemic venous system of the lower esophagus.
Esophageal and paraesophageal varices are supplied primarily by the left gastric vein and typically drain into the azygos/hemiazygos venous system.