Veins of the thoracic wall (English)

The venous drainage of the thoracic wall is accommodated by intercostal veins that accompany the intercostal arteries. Anteriorly, there are nine anterior intercostal veins that drain into the musculophrenic/internal thoracic veins. On the lateroposterior aspect, there are eleven posterior intercostal veins and the subcostal vein. Most of the posterior intercostal veins drain directly into the azygos venous system (right 4th-11th ➝ azygos vein, left 4th-7th ➝ accessory azygos vein, left 8th-11th ➝ hemiazygos vein). The uppermost, supreme intercostal vein on either side drains directly into the ipsilateral brachiocephalic vein. Additionally, the 2nd and 3rd posterior intercostal veins merge to form a superior intercostal vein on each side. The left superior intercostal vein goes on to drain into the left brachiocephalic vein, while the right one drains into the azygos vein.