The thoracoepigastric vein is a vital vessel that runs through the thorax and abdomen. It's also referred to as the superficial epigastric vein and the lateral thoracic vein. The latter arises from both sides of the thorax and drains the chest wall muscles into the axillary vein. Similarly, the former is a tributary of the great saphenous vein which is a long vein that runs from the groin to the ankle. Another synonym for the thoracoepigastric vein is the thoracodorsal vein. It runs in the opposite direction of the lateral thoracic vein - from the posterior chest wall to the axillary vein.