Careful Dissection of the Distal Ureter Is Highly Important in Nerve-sparing Radical Pelvic Surgery: A 3D Reconstruction and Immunohistochemical Characterization of the Vesical Plexus.

OBJECTIVE: Radical hysterectomy with pelvic lymphadenectomy (RHL) is the preferred treatment for early-stage cervical cancer. Although oncological outcome is good with regard to recurrence and survival rates, it is well known that RHL might result in postoperative bladder impairments due to autonomic nerve disruption. The pelvic autonomic network has been extensively studied, but the anatomy of nerve fibers branching off the inferior hypogastric plexus to innervate the bladder is less known. Besides, the pathogenesis of bladder dysfunction after RHL is multifactorial but remains unclear. We studied the 3-dimensional anatomy and neuroanatomical composition of the vesical plexus and describe implications for RHL. MATERIALS AND METHODS: Six female adult cadaveric pelvises were macroscopically dissected. Additionally, a series of 10 female fetal pelvises (embryonic age, 10-22 weeks) was studied. Paraffin-embedded blocks were transversely sliced in 8-µm sections. (Immuno) histological analysis was performed with hematoxylin and eosin, azan, and antibodies against S-100 (Schwann cells), tyrosine hydroxylase (postganglionic sympathetic fibers), and vasoactive intestinal peptide (postganglionic parasympathetic fibers). The results were 3-dimensionally visualized. RESULTS: The vesical plexus formed a group of nerve fibers branching off the ventral part of the inferior hypogastric plexus to innervate the bladder. In all adult and fetal specimens, the vesical plexus was closely related to the distal ureter and located in both the superficial and deep layers of the vesicouterine ligament. Efferent nerve fibers belonging to the vesical plexus predominantly expressed tyrosine hydroxylase and little vasoactive intestinal peptide. CONCLUSIONS: The vesical plexus is located in both layers of the vesicouterine ligament and has a very close relationship with the distal ureter. Complete mobilization of the ureter in RHL might cause bladder dysfunction due to sympathetic and parasympathetic denervation. Hence, the distal ureter should be regarded as a risk zone in which the vesical plexus can be damaged.

Optimal plane for nerve sparing total mesorectal excision, immunohistological study and 3D reconstruction: an embryological study.

AIM: Genito-urinary complications are frequent after rectal surgery and are often due to nerve damage. The relationship between the pelvic nerves and surgical planes are unclear. The aim of the study was to determine the relationship between the inferior hypogastric plexus and the fascia of the lateral pelvic wall and between Denonvilliers' fascia and the efferent branches of the inferior hypogastric plexus. METHOD: Computer-assisted anatomical dissection was used. Serial histological sections were made from six human foetuses and a male adult. Sections were stained with haematoxylin and eosin, Masson's trichrome and immunostainings. The sections were then digitalized and reconstructed in three dimensions. RESULTS: The inferior hypogastric plexus was situated in a virtual space between the fascia propria of the rectum and the fascia on the upper surface of the levator ani. During the lateral dissection, the optimal surgical plane is the plane of the fascia propria of the rectum. We located Denonvilliers' fascia in three dimensions. It plays the role of a protective sheet for the neurovascular bundle. The optimal plane for nerve preservation is situated behind Denonvilliers' fascia. CONCLUSION: This study has enabled a clear visualization of the optimal planes to perform total mesorectal excision while ensuring nerve preservation. Three-dimensional visualization clearly helps to bridge the gap between histological examination and the findings of surgery.

Division of autonomic nerves within the neurovascular bundles distally into corpora cavernosa and corpus spongiosum components: immunohistochemical confirmation with three-dimensional reconstruction.

BACKGROUND: Detailed knowledge of the distribution and distal course of periprostatic nerves is essential to improve functional outcomes (erection and continence) after radical prostatectomy (RP). OBJECTIVE: To describe the location of nerve fibres within neurovascular bundles (NVBs) and around the prostate by three-dimensional (3D) computer-assisted anatomic dissection (CAAD) in human foetuses and adult cadavers. DESIGN, SETTING, AND PARTICIPANTS: Serial transverse sections of the pelvic portion were performed in seven human male foetuses and four male adult cadavers. Sections were treated by histologic coloration and neuronal immunolabelling of S100 protein. 3D pelvic reconstruction was achieved with digitised serial sections and WinSurf software. MEASUREMENTS: We evaluated the distribution of nerve fibres within the NVB qualitatively. The distribution of periprostatic nerves was also evaluated quantitatively in the adult specimens. RESULTS AND LIMITATIONS: Periprostatic nerve fibres were dispersed around the prostate on all sides with a significant percentage of these fibres present in the anterior and anterolateral sectors. At the prostate apex and the urethral levels, the NVBs have two divisions: cavernous nerves (CNs) and corpus spongiosum nerves (CSNs). The CNs were a continuation of the anterior and anterolateral fibres around the apex of the prostate, travelling towards the corpora cavernosa. The CSNs were a continuation of the posterolateral NVBs, and they eventually reached the corpus spongiosum. The limitations of this study were the small number of specimens available and the lack of functional information. CONCLUSIONS: The anterolateral position of CNs at the apex of the prostate and the autonomic innervation towards the corpus spongiosum via CSNs indicate possible ways to minimise the effect of prostate surgery on sexual function. The ideal dissection plane should probably include the preservation of the anterolateral tissues and fascias to avoid CN lesions. Anatomic knowledge gained from CAAD pertains directly to proper surgical technique and subsequent recovery of erectile function after RP.

Development of the human retroperitoneal fasciae.

INTRODUCTION: Although the renal fascia (RF), ureteral sheath, lateroconal fascia (LF) and hypogastric nerve are critical landmarks for retroperitoneal surgery, their laminar relationships require clarification. MATERIALS AND METHODS: Horizontal sections (hematoxylin-eosin staining) of human fetuses at two different developmental stages [9-12 (3 fetuses, crown-rump length, CRL 40-65 mm) and 20-25 weeks of gestation (9 fetuses, CRL 152-220 mm)] were compared. RESULTS: In the early-stage group, the pararenal space had already formed between the posterior RF and the transversalis fascia (TF). The anterior RF extended along the peritoneum and often fused with the latter. In the late-stage group, the posterior RF extended inferomedially toward the anterior aspect of the aorta and inferior vena cava. However, at the level of the renal hilus, the posterior RF was connected with vascular sheaths of the great vessels. The LF was seen developing as a fasciculation of the multilaminar structure in the pararenal space. However, on the posterolateral side of the colon after retroperitoneal fixation, the fusion fascia of the peritoneum could also be identified as LF. CONCLUSIONS: A common sheath for ureters and hypogastric nerves appeared to be likely on the inferior side of the kidney. The LF did not appear to be a primary structure such as the RF, but a result of secondary mechanical stress due to fatty tissue developing earlier along the TF than in the perirenal space. However, the suggested similarity between LF and fusion fascia in the plane occupied was a likely cause for misinterpreting the laminar configurations during surgery.

The uterosacral complex: ligament or neurovascular pathway? Anatomical and histological study of fetuses and adults.

The aim of this study was to define the anatomical relationships of the uterosacral ligament complex (USLC) and to analyze histologically its content. Three fetal and four adult cadavers were used. Anatomical dissections were carried out. Eight fresh biopsies (four fetal and four adult) of the USLC were analyzed histologically and immunohistochemically. Specimens were stained with hematoxylin eosin safran coloration, with anti-nervous cell antibodies (PS 100) and with anti-smooth muscle antibodies (to visualize vessel walls). By removing the visceral pelvic fascia, nervous fibers were found within the USLC forming the hypogastric plexus. Histologically, the USLC contained connective tissue, nervous fibers, sympathetic nodes, vessels, and fatty tissue. No structured ligamentous organization was identified. The uterosacral "ligament" is a "complex" integrating connective tissue as well as nervous and vascular elements. Radical excisions and USLC suspension during pelvic floor reconstructive surgery should be performed with caution in order to preserve pelvic innervation.

[Anatomic and clinical evidence of intrapelvic pudendal nerve and its relation with striated sphincter of the urethra]. / Evidencias anatómicas y clínicas sobre el pudendo intrapélvico y su relación con el esfínter estriado de la uretra.

OBJECTIVE: To demonstrate that somatic innervation of the urethrae striate sphincter is intrapelvic and not through an internal pudendal nerve, an extrapelvic nerve in its entire path. To study the relationship of the pelvic plexus with genito-urinary organs and its surgical implications. METHODS: 6 embryos and 2 fetuses, sliced and stained with techniques suitable for nervous structures were studied. Sequential observation of the pelvic plexus structures and the internal pudendal nerve was carried out using light microscopy. Three-dimensional reconstruction of the two fetuses was performed to study the relationships of these structures with the genito-urinary organs. RESULTS: A nervous branch was identified in the 19, 25 and 30 mm long specimens that started at the internal pudendal nerve and joined the hypogastric ganglion close to the site of pelvic nerves binding. Hypogastric ganglion efferent branches penetrating the striate sphincter after a short descendent run were seen in the 30 and 39 mm embryos. CONCLUSIONS: Our findings confirm that the urethrae striate sphincter received the autonomous and somatic innervation from the pelvic plexus and, therefore, is susceptible to damage during cancer related surgery of the pelvic organs. An improved knowledge of these structures and the use of nerve preservation surgical techniques can reduce the incidence of post-operative incontinence in this type of surgery.

Ontogeny of neurotransmitter systems in the paracervical ganglion and uterine cervix of the rat.

BACKGROUND: The paracervical ganglia (PG) are components of the pelvic plexus that provides sensory and motor innervation to the reproductive system of the female rat. Several neurotransmitters including norepinephrine (NE), acetylcholine (ACh), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) are present in neurons of the adult PG and in axons innervating the adult uterus and uterine cervix. The current study was undertaken to describe the onset of immunoreactivity of these neurotransmitters and neuropeptides during development. METHODS: Female rats, ages E18 to P36, were prepared for immunohistochemistry for TH (tyrosine hydroxylase, a marker of noradrenergic neurons), NPY, or VIP as well as the histochemical demonstration of acetylcholinesterase (AChE). RESULTS: All four markers were detected in neurons of the PG at E18. Changes in the appearance of these markers from E18 to P36 reflected previously described growth changes in the PG. Axons containing AChE, TH, NPY, or VIP were first detected within the cervix at E20. Immunopositive axons first appeared as thick, unbranched structures at the outermost portion of the cervical myometrium. Over time, these axon bundles ramified to form discrete varicose axons. The ingrowth was similar for axons containing each of the four markers. CONCLUSIONS: The relative density of each neuronal type in the PG was reflected in the density of axons containing the same marker in the cervix. Changes in neurotransmitter/neuropeptide staining of PG neurons or axons in the cervix were not observed as the animals approached puberty.