Periaortic lymph nodes
The periaortic lymph nodes (also known as lumbar) are a group of lymph nodes that lie in front of the lumbar vertebrae near the aorta. These lymph nodes receive drainage from the gastrointestinal tract and the abdominal organs. 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 right paraaortic nodes, are situated partly  in front of the inferior vena cava near the termination of the renal vein, and partly behind it on the origin of the psoas major, and on the right crus of diaphragm. 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. The paraaortic and retroaortic nodes receive: 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 dissection or biopsy in the treatment or diagnosis of cancer. A dissection usually includes the region from the bifurcation of the aorta to the superior mesenteric artery or the renal veins.