Lumbar trunk

Last revised by Craig Hacking on 13 Oct 2022

The lumbar trunks (TA: truncus lumbalis) are paired lymphatic trunks that join to form the cisterna chyli, forming an integral part of the lymphatic system. The lumbar trunks carry lymph from the infraumbilical abdominal wall, pelvis and lower limbs 1,2. The intestinal trunk in the majority of people drains into the left lumbar trunk rather than directly into the cisterna chyli.

Gross anatomy


The left and right lumbar trunks course adjacent and parallel to the abdominal aorta and inferior vena cava. They sit anterior to the diaphragmatic crurasympathetic chain and the medial border of psoas major.


The lumbar trunks ascend from the lateral aortic nodes, which themselves drain the: 5

  • deep layers of the infraumbilical abdominal wall
  • paired retroperitoneal viscera of the abdomen (kidneys and adrenal glands)
  • pelvic walls and viscera (including the gonads)
  • efferents from the common Iliac nodes draining the lower limbs

The lumbar trunks terminate directly or indirectly in the cisterna chyli.

Variant anatomy

The precise tributaries that form the cisterna chyli exhibit a considerable array of anatomic variance. The left lumbar trunk more commonly drains directly into the cisterna chyli than does the right lumbar trunk 5,6.

Radiographic features


The lumbar lymphatic trunks may be seen on abdominal CT but could only be confidently identified in ~5% patients 4. However this is a very old study and with a modern CT it is probably easier to visualize these structures.


The left and right lumbar trunks can be seen in the majority of individuals on heavily T2-weighted MRI (e.g. MRCP-type sequences) as they ascend along the left and right paravertebral gutters. In a study of 125 patients specifically looking for these structures retrospectively on MRCP they were confidently identified in 70% cases 1.

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