The periaortic lymph nodes are different from the paraaortic lymph nodes. The periaortic group is the general group, that is subdivided into: preaortic, paraaortic, and retroaortic groups. The paraaortic group is synonymous with the lateral aortic group.
Divisions
The periaortic lymph node group is divided into three subgroups: preaortic, paraaortic, and retroaortic:
The retroaortic group are sometimes included in the paraaortic group due to their position (which is also lateral) and the same pattern of lymphatic drainage.
The left paraaortic nodes form a chain on the left side of the abdominal aorta in front of the origin of the psoas major and on the left crus of the diaphragm.
(d) the lymphatics draining the lateral abdominal muscles and accompanying the lumbar veins
Most of the efferent vessels from the paraaortic nodes converge to form the right and left lumbar trunks which join the cisterna chyli, but some enter the preaortic and retroaortic lymph nodes, and others pierce the crura of the diaphragm to join the lower end of the thoracic duct.
Dissection
The lateral aortic lymph nodes, typically 15 to 20 on each side, are the ones usually chosen for dissectionorbiopsy in the treatment or diagnosis of cancer.