Left ascending lumbar vein
Vena lumbalis ascendens sinistra
A vertical vein on the left of the lumbar spine, linking the common iliac and lumbar veins below with the hemiazygos vein above.
At a glance
- English
- Left ascending lumbar vein
- Latin (TA2)
- Vena lumbalis ascendens sinistra
- System
- Vein
- Region
- Trunk
- Side
- Single, on the midline
About the left ascending lumbar vein
The left ascending lumbar vein runs upwards on the posterior abdominal wall beside the lumbar vertebral bodies. It lies in front of the roots of the transverse processes and behind psoas major, so it is hidden from an anterior view of the abdomen until the muscle is moved aside.
Below, it usually begins from the left common iliac vein. As it climbs it is joined by the left lumbar veins, which run backwards around the sides of the vertebral bodies from the body wall, so that it forms a longitudinal channel connecting each of them. It also communicates with the vertebral venous plexuses through the intervertebral foramina.
At the level of the twelfth rib it unites with the left subcostal vein. The vessel formed by this union is the hemiazygos vein, which passes into the thorax by piercing the left crus of the diaphragm or passing behind it, and then runs up beside the vertebral bodies before crossing to join the azygos vein. On the left the ascending lumbar vein often also has a connection with the left renal vein.
The ascending lumbar veins matter most as a bypass. If the inferior vena cava is blocked or tied, blood from the lower body can reach the superior vena cava through the ascending lumbar, hemiazygos and azygos veins, as well as through the vertebral plexuses. These channels also explain why tumours and infection in the pelvis and abdomen can spread to the spine. Surgeons working on the lumbar spine from the side or the front take care with these veins, since they lie close to the vertebral bodies and can bleed briskly.
Course and drainage
- Begins at
- Usually from the left common iliac vein, beside the lower lumbar spine.
- Drains into
- Joins the left subcostal vein to form the hemiazygos vein at the level of the twelfth rib.
- Drains
- Collects the left lumbar veins and links the iliac and caval drainage with the hemiazygos and azygos system.
Anthromica
See the left ascending lumbar vein where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
