A persistent left superior vena cava may be associated with the presence of two azygos veins. |
The thoracic duct is located slightly ventral and medial to the azygos vein. |
When this occurs the posterior intercostal veins on the left side of the thorax may drain into the azygos vein independently. |
The Edentates, at any rate the American forms, have a double vena cava posterior and no azygos vein. |
I read that problems with the azygos veins are difficult to see without a venogram. |
Through the crura pass the splanchnic nerves, and in addition to these the left crus is pierced by the vena azygos minor. |