[2] Because the inferior vena cava is on the right half of the body, the left renal vein is longer than the right one.

The renal veins empty into the inferior vena cava, entering it at nearly a 90° angle.

[3] This is in contrast to the right side of the body, where these veins drain directly into the IVC.

[3] The anatomical relations of the two renal veins are bilaterally asymmetrical.

[1] It passes through the angle formed by the abdominal aorta (situated posteriorly), and superior mesenteric artery (situated anteriorly) (increased acuteness of this angle may lead to the left renal vein being "pinched" between the two arteries, with the resulting compression impairng blood flow through the vein, a condition known as nutcracker syndrome).