Left ascending lumbar vein

The left ascending lumbar vein originates from the left common iliac or iliolumbar vein. It ascends vertically in the posterior abdominal wall, receiving the left lumbar veins. it is located posterior to the psoas major muscle and anterior to the lumbar transverse processes. The left ascending lumbar vein ends approximately the T12-L2 vertebral levels, to become the hemiazygos vein (or join the hemiazygos vein if coming from the left renal vein).

The left ascending lumbar vein can be considered the abdominal counterpart of the hemiazygos vein.