What is the location of lateral aortic (para-aortic) lymph nodes and lumbar lymph nodes?

From the Guidelines

Lateral aortic (para-aortic) lymph nodes and lumbar lymph nodes are located in the retroperitoneal space of the abdomen, alongside the abdominal aorta, with the lateral aortic lymph nodes specifically lying on either side of the aorta, and the lumbar lymph nodes being another name for the para-aortic lymph nodes at the level of the lumbar vertebrae. The location of these lymph nodes is crucial for understanding the lymphatic drainage pathway, particularly in the context of abdominal and pelvic cancers. Key points about their location include:

• The right lateral aortic nodes are positioned between the aorta and the inferior vena cava
• The left lateral aortic nodes are situated lateral to the aorta
• These nodes receive lymphatic drainage from various areas, including the lower limbs, pelvis, reproductive organs, kidneys, adrenal glands, and portions of the intestines, as discussed in the context of testicular cancer staging and surveillance 1. Their positioning along major blood vessels makes them important in the lymphatic drainage pathway, as they filter lymph before it enters the thoracic duct and eventually returns to the bloodstream. These nodes are clinically significant as they can be sites of metastasis for various abdominal and pelvic cancers, including testicular, ovarian, and uterine malignancies, and can be assessed through imaging studies like CT scans or MRI for diagnostic purposes, with CT being the reference standard imaging test used for assessing the retroperitoneum for the presence of metastatic lymphadenopathy 1.

From the Research

Location of Lateral Aortic (Para-aortic) Lymph Nodes

• The para-aortic lymph nodes are located close to the aorta, with specific groups including paracaval, precaval, and retrocaval nodes depending on their relationship with the vena cava 2.
• These nodes can also be found in the intercavo-aortic region, situated between the vena cava and aorta 2.
• The study by 3 found that the mean distance from the centre of the para-aortic nodes to the aorta was 8mm, with no nodes superior to the T12-L1 interspace or inferior to the L5-S1 interspace.

Location of Lumbar Lymph Nodes

• Lumbar lymph nodes are part of the lymphatic system in the retroperitoneum and can be found in the area superior and inferior to the superior mesenteric artery (SMA) 4.
• The average number of lymph nodes in the area superior to the SMA was 17.4, and 13.3 in the area inferior to the SMA 4.
• The study by 2 also mentions that the lymphatic system of the pelvis is divided into six groups, depending on the relationship with the pelvic blood vessels, but does not specifically discuss the location of lumbar lymph nodes.

Relationship with Surrounding Structures

• The para-aortic lymph nodes are located near the aorta and vena cava, and their relationship with these structures is important for surgical and diagnostic procedures 3, 2.
• The study by 5 describes a technique for biopsying para-aortic lymph nodes without traversing the aorta, by passing a needle through the esophagus into the mediastinum just medial to the left subclavian artery.
• The location of lumbar lymph nodes in relation to surrounding neural tissue is also important, as preserving this tissue can be beneficial for patients with advanced gastric cancer 4.