The superior hypogastric plexus is a flat network of sympathetic and visceral afferent fibres lying in the retroperitoneum anterior to the fifth lumbar vertebra and the sacral promontory, between the two common iliac arteries. It is formed by the coalescence of lumbar splanchnic nerves from the lumbar sympathetic trunks and parasympathetic contributions. It divides inferiorly into the two hypogastric nerves that descend to the inferior hypogastric plexuses on each side.
The superior hypogastric plexus is the presacral nerve and is the structure divided in presacral neurectomy for chronic pelvic pain and primary dysmenorrhoea. It transmits pain afferents from the uterus, fallopian tubes, proximal ureter, and sigmoid colon. Injury during anterior lumbar spine surgery (ALIF) and aortoiliac surgery damages this plexus, causing retrograde ejaculation in men from sympathetic denervation of the bladder neck. The plexus lies just below the aortic bifurcation and the inferior mesenteric artery and is identified as a white fibrous condensation in this retroperitoneal zone.
Surgical trauma to the superior hypogastric plexus during anterior lumbar spine surgery or aortoiliac bypass denervates the sympathetic supply to the bladder neck and vas deferens, preventing bladder neck closure during ejaculation and producing retrograde ejaculation, an important complication for fertility.
Deliberate division of the superior hypogastric plexus at the sacral promontory interrupts uterine pain afferents, providing effective pain relief in primary dysmenorrhoea and central pelvic pain from endometriosis, with retrograde ejaculation as an unacceptable side effect in men.
