All of the following drain into azygous vein, except
High-Yield Explanation
Accessory hemiazygous vein drain at the level of upper border of 8th thoracic veebra. 5th to 11th right posterior intercostal veins are tributaries of azygos vein. Left superior intercostal veins are tributaries of hemizygous and accessory hemiazygous vein. B D Chaurasia 7th edition Page no: 233