The distribution of the inferior hypogastric plexus in female pelvis

Abstract

Elements that comprise the inferior hypogastric plexus are difficult to expose, intricate, and highly variable and can easily be damaged during local surgical procedures. We aimed to highlight, through dissection, the origin, formation, and distribution of the hypogastric nervous structures and follow them in the female pelvis. We performed detailed dissections on 7 female formalin-fixed cadavers, focusing on structures surrounding the pelvic organs. For each hemipelvis, we removed the peritoneum from the pelvic floor, and after we identified the hypogastric nerves, we continued our dissection towards the inferior hypogastric plexuses, following the branches of the latter. Laterorectally, the hypogastric nerves form the inferior hypogastric plexus, a variable structure – nervous lamina, neuronal network (more frequently), or sometimes a combination of them. We identified three components of the inferior hypogastric plexus. The anterior bundle travels towards the base of the urinary bladder, the middle part innervates the uterus and the vagina, and the posterior segment provides the innervation of the rectum. The plexus can be identified after removing the pelvic peritoneum and the subperitoneal adipose tissue. Intraoperatively, the structures can be preserved by using an immediately-subperitoneal dissection plane. The variable branches are relatively well-organized around the pelvic vessels, supplying the urinary bladder, the genital organs, and the rectum. The ureter is surrounded by some branches, especially in its last segment, and it also receives innervation directly from the hypogastric nerve. Close to the viscera, the nerves enter neurovascular plexuses, making the intraoperative separation of the nerves and the vessels virtually impossible.

Anatomical Location of the Vesical Branches of the Inferior Hypogastric Plexus in Human Cadavers

“…These parasympathetic pelvic splanchnic nerves join inferior branches of the hypogastric nerves to form the inferior hypogastric plexus (IHP, also termed the pelvic plexus [4]), located on both the right and left sides of the pelvis [5][6][7][8]. Sympathetic sacral splanchnic nerves from sacral located sympathetic ganglia also send branches into the IHP [9][10][11]. The anterior division of the IHP supplies nerve fibers to the bladder and ureter (i.e., vesical branches of the IHP, also known as vesical branches of the pelvic nerve [12][13][14][15][16], anterior branches of the IHP [9,17,18], and bladder nerve branches [10]).…”

Surgical Anatomy and Dissection of the Hypogastric Plexus in Nerve-Sparing Radical Hysterectomy

“…In contrast, the pelvic splanchnic nerves (PSNs) (arising from the S2–S4 anterior sacral roots) provide the parasympathetic innervation of the pelvis. The IHP is an intricate plexus, which is formed by the HNs (mainly sympathetic and secondarily parasympathetic innervation), pelvic splanchnic nerves (parasympathetic), and sacral splanchnic nerves (sympathetic innervation from multiple tiny nerve fibers originating from the sacral sympathetic ganglions of the sympathetic trunk) [ 3 , 4 , 5 , 6 , 7 ]. Gynecologic oncologic procedures such as paraaortic (inframesenteric) or presacral lymphadenectomy and radical hysterectomy are often associated with an injury to the sympathetic and parasympathetic branches of the autonomic nervous system [ 6 , 7 ].…”

“…It is a bilateral network of nerves, which lies in a sagittal plane slightly anterolateral to the mesorectum, lateral to the vagina and rectum, and posterolateral to the base of the bladder. The IHP can be dissected close to the parietal pelvic fascia [ 1 , 3 , 5 , 6 , 7 ]. The superior part of the IHP is located just below the lateral margin of the rectouterine/rectovaginal ligament within the leaves of the broad ligament retroperitoneally.…”

“…The inferior part of the plexus is more condensed compared to the superior part [ 1 ]. The length (15–40 mm) and thickness (10–30 mm) of the IHP vary in medical literature [ 1 , 3 , 6 , 7 , 18 , 19 , 20 , 21 ]. The IHP can be found along the posterior aspect of the internal iliac artery and vein.…”

“…Traditionally, the anatomical description of the IHP has delineated two main plexuses, which are the anterior, comprising the vesical and uterovaginal plexuses, and the postero-medial, rectal plexus [ 5 , 6 ]. However, other authors categorize the IHP into three distinct plexuses: anterior (vesical), intermediate (uterovaginal), and posterior (rectal) [ 3 ]. Fuji et al offered a different view, describing the IHP as being formed by a cross-shaped nerve bundle, with the lateral part being the PSN (S2–S4), medial (uterovaginal plexus), posterior (hypogastric nerve), and anterior bladder nerve branches (BNBs) [ 21 ].…”