The abdominal aortic plexus is a dense autonomic network surrounding the abdominal aorta below the diaphragm, formed by contributions from the greater, lesser, and least splanchnic nerves and the lumbar splanchnic nerves. It gives rise to and communicates with the subsidiary plexuses of the abdominal viscera including the celiac, superior mesenteric, renal, inferior mesenteric, and superior hypogastric plexuses, effectively distributing autonomic supply throughout the abdominal cavity.
The abdominal aortic plexus is disrupted during retroperitoneal lymph node dissection (RPLND) for testicular cancer, where removal of para-aortic nodes inevitably damages the plexus fibres, causing retrograde ejaculation in up to 90% of patients with bilateral dissection. Nerve-sparing RPLND identifies and preserves the sympathetic fibres descending to the superior hypogastric plexus, dramatically reducing retrograde ejaculation rates while maintaining oncological adequacy. The plexus is also involved in aortic aneurysm inflammatory disease and retroperitoneal fibrosis.
Bilateral retroperitoneal lymph node dissection disrupts the abdominal aortic plexus sympathetic fibres controlling the bladder neck and vas deferens, causing retrograde ejaculation in the majority of patients; nerve-sparing technique preserving the descending sympathetic chains reduces this complication substantially.
Idiopathic or drug-induced retroperitoneal fibrosis encases the aortic plexus along with the ureters and great vessels in fibrous tissue, producing chronic abdominal and back pain from plexus compression requiring biopsy to exclude lymphoma and treatment with corticosteroids or surgical ureterolysis.
