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International audience; Introduction: The aim of the present study was to describe autonomic urethral sphincter (US) innervation using specific muscular and neuronal antibody markers and 3D reconstruction. Material and Methods: We performed en-bloc removal of the entire pelvis of three male human fetuses between 18 and 40 weeks. Serial whole mount sections (5μm intervals) were stained and investigated. The sections were stained with Masson's trichrome and Eosin Hematoxylin, and immunostained with: anti-SMA antibody for smooth muscle; anti-S100 antibody for all nerves; and anti-PMP22 antibody, anti-TH antibody, anti-CGRP antibody, anti-NOS antibody for somatic, adrenergic, sensory and nitrergic nerve fibers, respectively. The slides were digitized for 3D reconstruction to improve topographical understanding. An animated reconstruction of the autonomic innervation of the US was generated. Results: The external and internal US are innervated by autonomic nerves of the inferior hypogastric plexus (IHP). These nerves are sympathetic (positive anti-TH antibody), sensory (positive anti-CGRP antibody), and nitrergic (positive anti-NOS antibody). Some autonomic fibers run within the neurovascular bundles, posterolaterally. Others run from the IHP to the posteromedial aspect of the prostate apex, above an through the rectourethral muscle. The external US is also innervated by somatic nerves (positive anti-PMP22 antibody) arising from the pudendal nerve, joining the midline but remaining below the rectourethral. Conclusions: This study provides anatomical evidence of an autonomic component in the innervation of the external US that travels in the neurovascular bundle. During radical prostatectomy, the rectourethral muscle and the neurovascular bundles are to be preserved, particularly during apical dissection.

Knowledge of the anatomy of the male pelvic floor is important to avoid damaging the pelvic floor muscles during surgery. We set out to explore the structure and innervation of the smooth muscle (SM) of the whole pelvic floor using male fetuses. We removed en-bloc the entire pelvis of three male fetuses. The specimens were serially sectioned before being stained with Masson's trichrome and hematoxylin and eosin, and immunostained for SMs, and somatic, adrenergic, sensory and nitrergic nerve fibers. Slides were digitized for three-dimensional reconstruction. We individualized a middle compartment that contains SM cells. This compartment is in close relation with the levator ani muscle (LAM), rectum, and urethra. We describe a posterior part of the middle compartment posterior to the rectal wall and an anterior part anterior to the rectal wall. The anterior part is split into (1) a centro-levator area of SM cells localized between the right and left LAM, (2) an endo-levator area that upholsters the internal aspect of the LAM, and (3) an infra-levator area below the LAM. All these areas are innervated by autonomic nerves coming from the inferior hypogastric plexus. The core and the infra-levator area receive the cavernous nerve and nerves supplying the urethra. We thus demonstrate that these muscular structures are smooth and under autonomic influence. These findings are relevant for the pelvic surgeon, and especially the urologist, during radical prostatectomy, abdominoperineal resection and intersphincteric resection. Clin. Anat., 2019. © 2019 Wiley Periodicals, Inc.

Introduction Innervation of the penis supports erectile and sensory functions. Aim This article aims to study the efferent autonomic (visceromotor) and afferent somatic (sensory) nervous systems of the penis and to investigate how these systems relate to vascular pathways. Methods Penises obtained from five adult cadavers were studied via computer-assisted anatomic dissection (CAAD). Main Outcome Measures The number of autonomic and somatic nerve fibers was compared using the Kruskal–Wallis test. Results Proximally, penile innervation was mainly somatic in the extra-albugineal sector and mainly autonomic in the intracavernosal sector. Distally, both sectors were almost exclusively supplied by somatic nerve fibers, except the intrapenile vascular anastomoses that accompanied both somatic and autonomic (nitrergic) fibers. From this point, the neural immunolabeling within perivascular nerve fibers was mixed (somatic labeling and autonomic labeling). Accessory afferent, extra-albugineal pathways supplied the outer layers of the penis. Conclusions There is a major change in the functional type of innervation between the proximal and distal parts of the intracavernosal sector of the penis. In addition to the pelvis and the hilum of the penis, the intrapenile neurovascular routes are the third level where the efferent autonomic (visceromotor) and the afferent somatic (sensory) penile nerve fibers are close. Intrapenile neurovascular pathways define a proximal penile segment, which guarantees erectile rigidity, and a sensory distal segment.

Pelvic floor disorders include urogenital and anorectal prolapse, urinary and faecal incontinence. These diseases affect 25% of patients. Most of time, treatment is primarily surgical with a high post-operative risk of recurrence, especially for pelvic organ prolapse. Vaginal delivery is the major risk factor for pelvic floor disorders through levator ani muscle injury or nerve damage. After vaginal delivery, 20% of patients experiment elevator ani trauma. These injuries are more common in case of instrumental delivery by forceps, prolonged second phase labor, increased neonatal head circumference and associated anal sphincter injuries. Moreover, 25% of patients have temporary perineal neuropathy. Recently, pelvic three-dimensional reconstructions from RMI data allowed a better understanding of detailed levator ani muscle morphology and gave birth to a clear new nomenclature describing this muscle complex to be developed. Radiologic and anatomic studies have allowed exploring levator ani innervation leading to speculate on the muscle and nerve damage mechanisms during delivery. We then reviewed the levator ani muscle anatomy and innervation to better understand pelvic floor dysfunction observed after vaginal delivery.

Background Injury to the levator ani muscle or pelvic nerves during pregnancy and vaginal delivery is responsible for pelvic floor dysfunction. Objective We sought to demonstrate the presence of smooth muscular cell areas within the levator ani muscle and describe their localization and innervation. Study Design Five female human fetuses were studied after approval from the French Biomedicine Agency. Specimens were serially sectioned and stained by Masson trichrome and immunostained for striated and smooth muscle, as well as for somatic, adrenergic, cholinergic, and nitriergic nerve fibers. Slides were digitized for 3-dimensional reconstruction. One fetus was reserved for electron microscopy. We explored the structure and innervation of the levator ani muscle. Results Smooth muscular cell beams were connected externally to the anococcygeal raphe and the levator ani muscle and with the longitudinal anal muscle sphincter. The caudalmost part of the pubovaginal muscle was found to bulge between the rectum and the vagina. This bulging was a smooth muscular interface between the levator ani muscle and the longitudinal anal muscle sphincter. The medial (visceral) part of the levator ani muscle contained smooth muscle cells, in relation to the autonomic nerve fibers of the inferior hypogastric plexus. The lateral (parietal) part of the levator ani muscle contained striated muscle cells only and was innervated by the somatic nerve fibers of levator ani and pudendal nerves. The presence of smooth muscle cells within the medial part of the levator ani muscle was confirmed under electron microscopy in 1 fetus. Conclusion We characterized the muscular structure and neural control of the levator ani muscle. The muscle consists of a medial part containing smooth muscle cells under autonomic nerve influence and a lateral part containing striated muscle cells under somatic nerve control. These findings could result in new postpartum rehabilitation techniques.

AIMS To characterize the nature and function of the levator ani muscle innervation pathways and to perform a comprehensive three-dimensional reconstruction of female pelvic innervation. METHODS A computer-assisted anatomical dissection protocol was applied to seven female human fetuses, after approval from the national biomedicine agency. Specimens were serially sectioned and immunostained for overall (antibody against protein S100), somatic (antibody against peripheral myelin protein 22), adrenergic (antibody against tyrosine hydroxylase), cholinergic (antibody against vesicular acetylcholine transferase), and nitrergic (antibody against the neural isoform of nitric oxide synthase) nerve fibers. Slides were digitized for three-dimensional reconstructions using WinSurf®. RESULTS Three main nerve pathways to the levator ani muscle were observed: the levator ani nerve, the pudendal nerve, and the inferior hypogastric plexus. The pudendal nerve was both somatic and autonomic, located below the levator ani muscle (infralevator pathway), supplying innervation to the inferior aspect of the levator ani muscle. The levator ani nerve was solely somatic, located above the levator ani muscle (supralevator pathway), supplying innervation to the superior aspect of the levator ani muscle. The inferior hypogastric plexus nerve fibers were solely autonomic, located in between the levator ani muscle and pelvic organs (endolevator pathway), supplying innervation to the medial portion of the levator ani muscle. CONCLUSIONS Our study provides a new representation of levator ani muscle innervation with three nerve pathways, and the levator ani muscle itself as an anatomical landmark.

Sphincter continence and sexual function require co-ordinated activity of autonomic and somatic neural pathways, which communicate at several levels in the human pelvis. However, classical dissection approaches are only of limited value for the determination and examination of thin nerve fibres belonging to autonomic supralevator and somatic infralevator pathways. In this study, we aimed to identify the location and nature of communications between these two pathways by combining specific neuronal immunohistochemical staining and three-dimensional reconstruction imaging. We studied 14 normal human fetal pelvic specimens (seven male and seven female, 15–31 weeks’ gestation) by three-dimensional computer-assisted anatomic dissection (CAAD) with neural, nitrergic and myelin sheath markers. We determined the precise location and distribution of both the supra- and infralevator neural pathways, for which we provide a three-dimensional presentation. We found that the two pathways crossed each other distally in an X-shaped area in two spatial planes. They yielded dual innervation to five targets: the anal sphincter, levator ani muscles, urethral sphincter, corpus spongiosum and perineal muscles, and corpora cavernosa. The two pathways communicated at three levels: proximal supralevator, intermediary intralevator and distal infralevator. The dorsal penis/clitoris nerve (DN) had segmental nitrergic activity. The proximal DN was nNOS-negative, whereas the distal DN was nNOS-positive. Distal communication was found to involve interaction of the autonomic nitrergic cavernous nerves with somatic nitrergic branches of the DN, with nitrergic activity carried in the distal part of the nerve. In conclusion, the pelvic structures responsible for sphincter continence and sexual function receive dual innervation from the autonomic supralevator and the somatic infralevator pathways. These two pathways displayed proximal, intermediate and distal communication. The distal communication between the CN and branches of the DN extended nitrergic activity to the distal part of the cavernous bodies in fetuses of both sexes. These structures are important for erectile function, and care should therefore be taken to conserve this communication during reconstructive surgery.

Introduction Little detailed information is available concerning autonomic and somatic nerve supply to the clitoris, potentially causing difficulties for nerve preservation during pelvic and perineal surgery. Aim To identify the location and type (nitrergic, adrenergic, cholinergic and sensory) of nerve fibers in the clitoris and to provide a three‐dimensional (3D) representation of their structural relationship in the human female fetus. Methods Serial transverse sections were obtained from five human female fetuses (18–31 weeks of gestation) and subjected to histological and immunohistochemical investigations; digitized serial sections were used to construct a 3D representation of the pelvis. Main Outcome Measures Pelvic‐perineal nerve location and type were evaluated qualitatively. Results The female neurovascular bundle (NVB) is the anteroinferior terminal portion of the inferior hypogastric plexus that runs along the postero‐lateral then lateral face of the vagina and is rich in nNOS‐positive fibers. The cavernous nerve (CN) is a thin ventrocaudal collateral projection of the NVB, and this projection does not strictly follow the NVB course. The CN runs along the lateral surface of the vagina and urethra and penetrates the homolateral clitoral crus. The CN provides adrenergic, cholinergic, and nitrergic innervation to the clitoris, but not sensory innervation. The spongious nerve (SN) is the terminal and main projection of the NVB and provides nitrergic innervation to the vestibular bulbs. The dorsal clitoris nerve (DCN), somatic branche of the pudendal nerve, runs along the superior surface of the clitoral crus and body and has a segmental proerectile nitrergic activity related to communicating branches with the CN. Conclusions “Computer‐assisted anatomic dissection” allowed the identification of the precise location and distribution of the autonomic and somatic neural supply to female erectile bodies, providing an anatomical basis for nerve‐sparing surgical techniques, and participating to the understanding of neurogenic female sexual dysfunction. Moszkowicz D, Alsaid B, Bessede T, Zaitouna M, Penna C, Benoit G, and Peschaud F. Neural supply to the clitoris: Immunohistochemical study with 3D reconstruction of cavernous nerve, spongious nerve and dorsal clitoris nerve in human fetus.

International audience; Some autologous tissues can restore erectile function (EF) in rats after a resection of the cavernous nerve (CN). However, a cavernous nerve crush injury (CNCI) better reproduces ED occurring after a nerve-sparing radical prostatectomy (RP). The aim was to evaluate the effect on EF of an autologous vein graft after CNCI, compared with an artificial conduit. Five groups of rats were studied: those with CN exposure, exposure+vein, crush, crush+guide and crush+vein. Four weeks after surgery, the EF of rats was assessed by electrical stimulation of the CNs. The intracavernous pressure (ICP) and mean arterial pressure (MAP) were monitored during stimulations at various frequencies. The main outcome, that is, the rigidity of the erections, was defined as the ICP/MAP ratio. At 10 Hz, the ICP/MAP ratios were 41.8%, 34.7%, 20.9%, 33.9% and 20.5%, respectively. The EF was significantly lower in rats if the CNCI was treated with a vein graft instead of an artificial guide. Contrary to cases of CN resection, autologous vein grafts did not improve EF after CNCI. In terms of clinical use, the study suggests to limit an eventual use of autologous vein grafts to non-nerve-sparing RPs.

Objectifs La denervation renale par radiofrequence endovasculaire (RF) au travers des arteres renales est une option emergente de traitement pour l’hypertension refractaire. Les resultats preliminaires sont discordants et le manque de connaissance de l’anatomie du plexus renal a ete souleve dans une etude prospective multicentrique. Notre objectif etait de decrire la localisation et les distances entre les fibres nerveuses du plexus renal et la lumiere vasculaire. Methodes Des coupes seriees transversales du tronc de trois fœtus humains et une dissection large des arteres renales de dix cadavres adultes ont ete effectuees. Les coupes ont ete traitees par coloration histologique au trichrome de Masson et par immunomarquage neuronal avec un anticorps anti-proteine S-100. Les fibres du plexus renal ont pu etre distinguees en utilisant un immunomarquage des fibres autonomes adrenergiques sympathiques (TH) et cholinergiques parasympathiques (VAChT). Les images bidimensionnelles ont ete reconstruites en trois dimensions par dissection anatomique assistee par ordinateur (DAAO) grâce au logiciel WinSurf a partir des coupes seriees numerisees. Resultats L’origine, les voies et la distribution sectorielle des nerfs du plexus renal ont ete decrits sur les fœtus ( Fig. 1 ) : nous avons observe une difference dans la repartition sectorielle autour des arteres principales et des arteres segmentaires. Les fibres nerveuses correspondent a des fibres autonomes adrenergiques sympathiques. L’etude des cadavres adultes a permis d’identifier le plexus renal jusqu’a dix millimetres (0–10 mm) de l’artere renale a son ostium. Au pourtour des arteres segmentaires de plus petit calibre, les nerfs sont plus proches (1–3 mm). Avec la reconstruction 3D du plexus renal, il a ete possible d’analyser les relations des fibres nerveuses avec tous les elements du hile (artere, veine et voies excretrices) ainsi qu’en intrarenal. Conclusion Ces donnees anatomiques nouvelles et precises de l’innervation renale peuvent fournir de nouvelles voies de recherches et de techniques therapeutiques pour l’HTA refractaire, en particulier concernant la profondeur de l’ablation et le diametre de la sonde de radiofrequence et ouvrir vers une denervation renale chirurgicale.

The purpose of this study was to identify the microscopic arterial vascularization of the corpora cavernosa (CC) of the penis using computer-assisted anatomic dissection (CAAD), determine the contribution of the different penile arteries towards this vascularization, detail the nature of cavernospongiosum shunts, and locate the anastomoses between these different arteries. Tissue specimens were taken from five donors who donated their bodies to science. The specimens were fixed in 10% formalin and sliced into a series of five 5-μm sections at intervals of 200 μm. The first section was stained with hematoxylin-eosin or Masson's trichrome and the second with anti-protein S100. The cavernous artery of the penis is not the only source of arterial vascularization of the CC. In four of the five cases studied, we found two to four perforating branches arising from the dorsal arteries of the penis that join up with the cavernous artery of the penis or that are solely responsible for the vascularization of the distal third of the penis. The bulbo-urethral and urethral arteries are situated outside of the tunica albuginea of the corpus spongiosum on their lateral and dorsal sides. The anastomoses do not occur between the cavernous artery of the penis and the corpus spongiosum but between the cavernous artery of the penis and the urethral artery on the surface of the tunica albuginea. All of these arteries are accompanied by nerve branches. The CC were found to be vascularized by both cavernous and dorsal arteries of the penis. Intrapenile vascularization is organized around four arterial axes, which are anastomosed by multiple neurovascular shunts.