Retro-aortic nodes

At a glance

English

Retro-aortic nodes

Latin (TA2)

Nodi retroaortici

System

Lymphatic

Region

Trunk

Side

Single, on the midline

About the retro-aortic nodes

The retro-aortic nodes, also called post-aortic nodes, are the smallest of the lumbar groups. They lie behind the abdominal aorta in its lower part, resting on the third and fourth lumbar vertebral bodies and the discs between them. Above them, at the level of the first and second lumbar vertebrae, is the cisterna chyli, the sac where the thoracic duct begins.

Behind the aorta here the lumbar arteries leave its back wall in pairs and pass round the vertebral bodies, and the left lumbar veins cross towards the inferior vena cava. The nodes sit among these vessels, with the anterior longitudinal ligament of the spine behind them. They are flanked by the lateral aortic nodes on the left and the intermediate lumbar nodes on the right.

Rather than draining organs directly, these nodes act as a link in the lumbar system. They take in lymph vessels coming from the lateral aortic nodes and from the pre-aortic nodes in front of the aorta, and they also receive some vessels from the posterior abdominal wall. Their efferents run up to the cisterna chyli.

Because they are deep and covered by the aorta, they are hard to see on ultrasound and are best assessed on CT or MRI. Like the other lumbar groups, they can enlarge in lymphoma or when cancers of the abdomen and pelvis spread along the lumbar chain, and surgeons must lift or roll the aorta to clear them in a full retroperitoneal dissection.

Course and drainage

Begins at

Lymph vessels from the lateral aortic and pre-aortic nodes, with a few from the posterior abdominal wall.

Drains into

Efferent vessels end in the cisterna chyli.

Drains

A link in the lumbar lymph system carrying lymph from neighbouring aortic groups to the cisterna chyli. They may enlarge in lymphoma or with spread of abdominal and pelvic cancers, and are hard to reach behind the aorta.