Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients.

PURPOSE: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). MATERIALS AND METHODS: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. RESULTS: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). CONCLUSION: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures.

Computer-assisted anatomic dissection (CAAD): evolution, methodology and application in intra-pelvic innervation study.

OBJECTIVE: Classic anatomical methods have limitations in micro determination of nerve fibre location. Furthermore, the precise detection of the nerve fibres nature is not possible by means of dissection. The combination of immunohistochemistry and three-dimensional reconstruction could be used to resolve these limitations of morphological sciences. Our aim is to describe the evolution of computer-assisted anatomic dissection (CAAD), which is an original method applied to study the distribution of intra-pelvic nerves in anatomic research. MATERIALS AND METHODS: Serial transverse sectioning of the pelvic region in rabbit, human fetus, infant and adult cadaver was performed. Sections were immuno-histochemically stained and digitized with a high optical resolution scanner. Photoshop 7 software was used in regrouping of the adult cadaver sections then a tri-dimensional reconstruction was achieved using WinSurf software. RESULTS: The 3D reconstruction of the immuno-histochemically stained histologic sections of the pelvis allowed for precise structural identification of the prostate and its innervations (in fetus, infant and adult). In addition, we reconstructed the entire intra-pelvic organs with accurate demonstration of the location of both adrenergic and cholinergic pathways. Moreover, we performed a virtual dissection of each of the pelvic structures with description of the exact location of the inferior hypogastric plexus, as well as the nature and the distribution of its fibres. CONCLUSION: The CAAD is an original method in anatomic research, which illustrates the fact that descriptive anatomy is still a dynamic science. This method allows for a 3D presentation of the intra-organic innervation, the nature of the nerve fibres, and the distribution of receptors and their neurotransmitters. This technique improves the understanding of the complex anatomic regions such as the pelvis from both surgical and educational point of view.

Autonomic-somatic communications in the human pelvis: computer-assisted anatomic dissection in male and female fetuses.

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.

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.

Tridimensional computer-assisted anatomic dissection of posterolateral prostatic neurovascular bundles.

BACKGROUND: Detailed knowledge of nerve distribution in the neurovascular bundle (NVB) is essential to preserve sexual function after prostatic surgery. OBJECTIVE: To identify the location as well as the type (adrenergic, cholinergic, and sensory) of nerve fibres within the NVB and to provide a three-dimensional (3D) representation of their structural relationship in the human male foetus. DESIGN, SETTING, AND PARTICIPANTS: Serial transverse sections were performed every 150-200 microm in the pelvic portion of six human male foetuses (15-20 wk of gestation). Sections were treated with histologic and immunohistochemical methods (hematin-eosin-safran, Luxol Fast Blue, immunolabelling of protein S100, vesicular acetylcholine transporter, tyrosine hydroxylase, calcitonin gene-related peptide, and substance P). The 3D pelvic reconstruction was obtained from digitised serial sections using WinSurf software. MEASUREMENTS: NVB nerve location and type were evaluated qualitatively. RESULTS AND LIMITATIONS: The 3D reconstruction allowed precise identification of pelvic organ innervation. Nerve fibres derived from the inferior hypogastric plexus followed two courses: posterior and lateral, providing cholinergic, adrenergic, and sensory innervation to seminal vesicles, vas deferens, prostate, and urethral sphincter. Cavernous nerve fibres did not strictly follow the NVB course; they were distributed at several levels, in a fanlike formation. The main limitations of this study were the limited number of specimens available due to legal restriction and the time-consuming nature of the manually performed stages in the method. CONCLUSIONS: The distribution of nerve fibres within the posterolateral prostatic NVB and the existence of mixed innervation in the posterior and lateral fibre courses at the level of the prostate and seminal vesicles give us an insight into how to minimise effects on sexual function during prostatic surgery. The 3D computer-assisted anatomic dissection represents an original method of applying anatomic knowledge to surgical technique to improve nerve preservation and decrease postoperative sexual complications.

Effect of a local delivery of triiodothyronine (T3) within neuroregenerative guide on recovery of erectile function in a rat-model of cavernous nerve injury.

INTRODUCTION: A promoting effect of thyroid hormones has been established on the maturation of central and peripheral nervous systems. However, effects on autonomic nerves have never been experimentally investigated. AIM: To assess the effect of a local treatment combining silicone guides and local administration of Triiodothyronine (T3) on the erectile function and the histological neuroregeneration of crushed cavernous nerves (CNs) in rats. METHODS: Forty-five rats were divided into five equal groups: SHAM surgery, guide without crush, crush, crush + guide, crush + guide + T3. All surgical procedures were bilateral. CNs were crushed with microvascular bulldog clamp of 100 g/cm(2). A silicone guide was placed around the nerves. The guides were filled with T3 neuroregenerative solution. MAIN OUTCOME MEASURES: Erectile function was assessed 10 weeks post-operatively. Intra-cavernous pressure (ICP) and mean arterial pressure (MAP) were monitored during electrical stimulation of CNs at various frequencies. The main outcome was hardness of erection defined as DeltaICP/MAP. Fluorescent immunohistochemical analysis of CNs was performed to assess regeneration of nerves morphologically. RESULTS: Electrophysiological data showed increased recovery of erectile function in the group with guide + T3 neuroregenerative solution compared with the empty guide. Immunohistochemical analysis of cavernous nerves demonstrated in morphology that regenerated axons were straighter in nerves with guide and more regular if guides had been filled with T3. CONCLUSION: The use of guides prevented axonal sprouting, facilitated functional neuroregeneration and enabled a local delivery of thyroid hormones. Triiodothyronine improved neuroregeneration and recovery of erectile function after a nerve-sparing-like injury in a rat model.

Coexistence of adrenergic and cholinergic nerves in the inferior hypogastric plexus: anatomical and immunohistochemical study with 3D reconstruction in human male fetus.

Classic anatomical methods have failed to determine the precise location, origin and nature of nerve fibres in the inferior hypogastric plexus (IHP). The purpose of this study was to identify the location and nature (adrenergic and/or cholinergic) of IHP nerve fibres and to provide a three-dimensional (3D) representation of pelvic nerves and their relationship to other anatomical structures. Serial transverse sections of the pelvic portion of two human male fetuses (16 and 17 weeks' gestation) were studied histologically and immunohistochemically, digitized and reconstructed three-dimensionally. 3D reconstruction allowed a 'computer-assisted dissection', identifying the precise location and distribution of the pelvic nerve elements. Proximal (supra-levator) and distal (infra-levator) communications between the pudendal nerve and IHP were observed. By determining the nature of the nerve fibres using immunostaining, we were able to demonstrate that the hypogastric nerves and pelvic splanchnic nerves, which are classically considered purely sympathetic and parasympathetic, respectively, contain both adrenergic and cholinergic nerve fibres. The pelvic autonomic nervous system is more complex than previously thought, as adrenergic and cholinergic fibres were found to co-exist in both 'sympathetic' and 'parasympathetic' nerves. This study is the first step to a 3D cartography of neurotransmitter distribution which could help in the selection of molecules to be used in the treatment of incontinence, erectile dysfunction and ejaculatory disorders.

The precise location and nature of the nerves to the male human urethra: histological and immunohistochemical studies with three-dimensional reconstruction.

OBJECTIVES: The precise location, origin and nature of nerve fibers innervating the male urethral sphincter have not been clearly established. Classical anatomical studies based on cadaver dissections have provided conflicting results concerning the location of somatic and autonomic nerve fibers. This study was designed to identify nerve fibers innervating the male urethral sphincter and to provide a three-dimensional representation of their tissue relations in the human male fetus. MATERIALS AND METHODS: Histology and immunohistochemistry (Hematein-Eosin-Safran, Luxol Fast Blue, Protein S 100 immunolabeling and smooth fibers actin immunolabeling) were performed in male external urethral sphincter of ten male fetuses (114-342 mm crown-rump length). Three-dimensional reconstruction of the urethral structure and innervation were obtained from serial sections using Surf Driver 3.5.3 software. RESULTS: The three-dimensional reconstruction of the same section levels with different strains allowed to identify the precise structure of the muscular layers and the nature of nervous elements (myelinated and unmyelinated), their distributions and their relations with the urethral wall, the prostate and the seminal vesicles. CONCLUSION: Histological and immunohistochemical three-dimensional reconstruction of the nervous elements of the urethral sphincter gives a very didactical understanding of the three dimensional arrangement of the urethral nerves and their relationships with the urethral layers. It allows a better understanding of the origin, the course and the nature of the nervous elements participating in the urinary continence.

Innervation of the female human urethral sphincter: 3D reconstruction of immunohistochemical studies in the fetus.

OBJECTIVES: The precise location, origin and nature of nerve fibers innervating the urethral sphincter have not been clearly established. Classical anatomical studies based on cadaver dissections have provided conflicting results concerning the location of pudendal and autonomic nerve fibers. This study was designed to identify nerve fibers innervating the urethral sphincter and to provide a three-dimensional representation of their tissue relations in the female human fetus. MATERIALS AND METHODS: Histology and immunohistochemistry (Masson's Trichromic, Luxol Fast Blue, Protein S 100 immunostaining and smooth fiber actin immunostaining) were performed on the external urethral sphincter of ten female fetuses with a crown-rump length of 112 to 340mm. Three-dimensional reconstructions of the urethral structure and innervation were obtained from serial sections using Surf Driver 3.5.3 software (David Moody and Scott Lozanoff). RESULTS: Three-dimensional reconstructions of the same sections with different stains demonstrated the precise structure of the muscle layers (smooth and striated muscle fibers) and nerve fibers (myelinated and unmyelinated) and their relations with the urethra and vaginal wall. The proximal third consisted of a circular smooth muscle sphincter, the middle third consisted of two circular layers of smooth and striated muscle fibers and the distal third consisted of a circular layer of smooth muscle fibers surrounded by an omega-shaped layer of striated muscle fibers. In the proximal third of the urethral sphincter, myelinated fibers were identified running with unmyelinated fibers from the pelvic plexus. These fibers were closely related to the lateral and anterior aspects of the vagina. Unmyelinated fibers entered the smooth muscle part of the sphincter at 4 o'clock and at 8 o'clock. Most myelinated fibers entered the sphincter at 3 o'clock and at 9 o'clock. CONCLUSION: Histological and immunohistochemical three-dimensional reconstruction of the anatomical structures of the urethral sphincter provides a better understanding of the origin and nature of the Innervation participating in urinary continence. It provides a very informative view of the three-dimensional arrangement of sphincter muscle layers.