Ascending lumbar vein

The ascending lumbar vein is a vein that runs up through the lumbar region on the side of the vertebral column.

Structure

The ascending lumbar vein is a paired structure. It starts at the common iliac veins. It runs superiorly, intersecting with the lumbar veins as it crosses them. It passes behind the psoas major muscle, but in front of the lumbar vertebrae.
When the ascending lumbar vein crosses the subcostal vein, it becomes one of the following:

the azygos vein.
the hemiazygos vein.

The first and second lumbar veins ends in the ascending lumbar vein

Clinical significance

Contrast medium may be injected into the ascending lumbar vein via the femoral vein in order to visualise the spinal canal.
The ascending lumbar vein may be punctured during catheterisation. This can cause bleeding into the dural space.