Vestibular Bulb Research Articles

The development of the external genitals in female human embryos and foetuses. Part 2: Vaginal vestibule, anal canal, perineal raphe and perineal cutaneous muscles.

Concomitant with the rupture of the cloacal membrane, the perineal skin epithelium thickens (see accompanying article). In this study, we establish in female embryos and foetuses that the thick skin area divides into ventral and dorsal areas at ~14 weeks and gradually becomes restricted to the vaginal vestibule and anal canal thereafter. The dense mesenchymal core of the labia minora, which forms at ~8 weeks, extends dorsally to the anal canal as a midline reinforcement. The skin epithelium overlying this reinforcement is much thinner than the flanking 'thick skin', and is supported by an interrupted basement membrane, which implies epithelial-mesenchymal transformation of the thin midline epithelium and the subsequent establishment of the perineal raphe by the merging of the adjacent thick epithelium. Meanwhile, the anogenital distance in the perineum increases rapidly in length. Perhaps as a consequence, the labia minora cover only the ventral third of the vaginal vestibule at 20 weeks. The endodermal ducts of Bartholin's glands are identifiable at 7 weeks, while acini form at ~12 weeks. The vestibular bulbs become identifiable at ~10 weeks and form vascular networks after ~14.5 weeks. After the rupture of the cloacal membrane, the diameter of the junction of the dorsal cloaca with the anal canal is just a pinhole but widens dorsoventrally after the 7th week. The cutaneous muscles of the perineal area form as a ventrally open U-shaped mesenchymal mass, from which the anal sphincter and bulbospongiosus muscle develop. In conclusion, our findings show that thick skin epithelium persists in the vaginal vestibule and anal canal.

(120) GETTING C-LITERATE: ELUCIDATING BULBOCLITORAL ERECTILE TISSUE ANATOMY AND HISTOLOGY FOR APPLICATIONS IN CANCER SURVIVORSHIP

Abstract Introduction Sexual function is a crucial component of overall well-being and is emerging as an important factor in health outcomes across multiple healthcare fields, including oncology. The bulboclitoris, composed of the clitoris and vestibular bulbs, is an erectile organ that has been largely understudied in comparison to other sexual organs, such as the vagina and penis. Recently, sexual health advocates have increased visibility for the bulboclitoris, highlighting its significance, particularly for patients who have undergone surgical procedures, experienced trauma, or undergone cancer treatments in that region. A deeper understanding of this organ is essential for better appreciation of its role and for advancing the treatment of sexual morbidity. Objective We aim to characterize the anatomic and histopathologic characteristics of the bulboclitoral erectile tissues using human cadaveric specimen dissection, histology, and immunohistochemistry. We hope that our findings can both serve as a translational bridge to understanding the effects of radiation and other oncologic interventions on the bulboclitoris on a cellular level and to establish the bulboclitoris as a unified organ in peer reviewed anatomic literature. Methods We evaluated the bulboclitoral erectile tissues on a structural and cellular level using multiple modalities. In order to visualize the bulboclitoris organ in its anatomic position, we used gross anatomic dissection (n = 2) and cross-sectioning (n = 1). In order to characterize the neurovasculature, endocrine function, musculature, and other cellular characteristics of the erectile tissues, samples were taken from multiple sections of the dissected bulboclitoral organs and from rapid autopsy (n = 2) for histopathological and immunohistochemical staining. We are analyzing these tissues using four stains, hematoxylin and eosin (H&E), trichrome, toluidine blue, and elastin; and eight antibodies, endothelial nitric oxide synthase (eNOS), factor VIII, smooth muscle actin (SMA), desmin, protein gene product 9.5 (PGP 9.5), tyrosine hydroxylase, anti-estrogen receptor (anti-ER), and anti-androgen receptor (anti-AR), using penile tissue as a control. Results We present the results of the gross dissections and some preliminary results of the histopathological and immunohistochemical staining. These dissections confirm the visibility of the bulboclitoris in its specified anatomical location and provide support for the existence of the residual spongy part (RSP) connecting the cavernous and spongy structures. Distinct features of the bulboclitoral erectile tissues are visualized and highlighted on the digitally scanned slides. The results of the histopathological and immunohistochemical analyses will further elucidate the anatomy of the organ. Conclusions The bulboclitoris is an organ that plays an essential role in sexual function. Thus far we have found supportive evidence for the hypothesis that the bulboclitoral erectile tissues function as one organ, homologous to the penile erectile tissues, based on the presence of the residual spongy part (RSP). Greater understanding of the makeup and cellular composition of the erectile tissues has the potential to increase our understanding of various medical treatments on sexual function, provide the basis for objective markers that can help to quantify the impact of any preventive or mitigating interventions, and lay the foundation to inform design of appropriate interventions for the preservation of sexual function in cancer survivorship. Disclosure No.

(005) MRI TECHNIQUES FOR IMAGING BIOMARKERS OF RADIATION-INDUCED DAMAGE TO FEMALE ERECTILE TISSUES AND OTHER GENITOPELVIC ORGANS

Abstract Introduction Difficulties with arousal and orgasm are common in female patients after pelvic radiation. Yet, current classifications of toxicity and normal tissues in radiation oncology account poorly for the anatomy and critical function of female erectile tissues (arousal and orgasm) with respect to patients’ capacities to continue to engage in pleasurable sexual behaviors after cancer treatment. MRI imaging biomarkers of dose-volume dependent radiation damage can provide objective measures of the impact of interventions, help predict sexual dysfunction, and allow for re-optimization of therapy for early mitigation of radiation damage to female erectile tissues. Objective The aim of this project is to develop and optimize MRI imaging techniques for female erectile tissues and other genitopelvic organs. Optimization of this MRI protocol will allow us to establish quantitative and qualitative indices of radiation damage to specific sexual organs, providing mechanistic insights into how to measure radiation damage of current and future therapies. Methods This prospective study includes two female-identifying volunteers with healthy female pelvic anatomy who underwent MRI scans using a 3.0T MRI (Prisma, Siemens Healthcare) scanner. The protocol (Table 1) included 2D T2-weighted turbo spin-echo (TSE) sequences in the axial (spatial resolution 0.5x0.5x2mm), coronal (spatial resolution 0.5x0.5x3mm), and sagittal planes (spatial resolution 0.3x0.3x2mm), T2-weighted with fat saturation in the axial plane (spatial resolution: 0.8x0.8x4mm) diffusion-weighted tensor imaging (DTI, axial plane with 30 diffusion directions and b-values 0s/mm2 and 400s/mm2, TR/TE: 3000/57ms, spatial resolution 1.3x1.3x5mm). Protocol optimization in healthy volunteers consisted of imaging without gadolinium contrast, while future imaging in patients will also include dynamic contrast-enhanced MRI (3D T1-weighted radial acquisition in the axial plane, with 4.7s temporal resolution, 20 slices, spatial resolution 0.8x0.8x2mm) and T1 mapping (axial plane variable flip angle, B1-corrected acquisition with 5 flip angles: 5, 10, 15, 20, 30 degrees, TR/TE: 5.9/2.4ms, with 0.8x0.8x2mm spatial resolution). The sexual regions of interest (ROIs) included the female external genitalia, vagina, bulboclitoris (clitoris and vestibular bulbs), pelvic neurovasculature, and pelvic floor muscles which were visualized and contoured per standard protocols. Results The axial T2-weighted TSE sequences in 2mm slices provided clear visualization of the female erectile tissues for contouring the bulboclitoris, vaginal canal, and external genitalia (Figure 1). The T2-weighted sequences with fat saturation allows us to conduct MR neurography to evaluate the three-dimensional visibility of the nerves (plexus, pudendal and cavernous), enabling us to localize and characterize nerve abnormalities with dose-dependent radiation damage (Figure 2). Perfusion time intensity curves created with the T1 DCE scans can assess changes in vasculature, and the initial areas under the time to signal intensity curve (IAUC) will act as biomarkers for erectile tissue perfusion and permeability. Additional biomarkers include ROI intensity and volume/thickness for both erectile tissues and the vagina wall, as well as fractional anisotropy for the vagina alone. Lastly, we explore the clinical applications of DTI with fiber tractography to evaluate pelvic floor musculature. Conclusions These MRI techniques will be the first to validate normal tissue toxicity imaging biomarkers for radiation damage, allowing us to objectively measure dose-dependent inflammatory, fibrotic and vasculogenic effects of radiotherapy. Disclosure No.

Evaluation of Sexual Side Effects in Patients after Chemoradiation and Brachytherapy for Gynecologic Cancers Involving the Lower Vagina and Bulboclitoris

Radiation toxicity to the bulboclitoris has not been previously investigated. This retrospective cohort study aims to report sexual side effects of patients who underwent radiotherapy for tumors involving the lower vagina, periurethra, and bulboclitoris (BC). Patients treated between 2017- 2022 for gynecologic cancer involving the low vagina were included. The high-risk clinical target volume (HR-CTV), bladder, rectum, and urethra were contoured on patient imaging during initial treatment planning. The BC was retrospectively contoured using T2 MRI sequences fused to the pre-treatment and brachytherapy CT simulation. Superiorly, the BC was defined as inferior to the pubic symphysis and attached to the suspensory ligament of the clitoris. Laterally, the crura extend on either side of the corpus. Inferiorly, the vestibular bulbs flank the urethra and vagina on either side, extending posteriorly to mid-vagina. Dosimetric data for the BC, vaginal morbidity using the CTCAE 4.0 for vaginal stenosis, and pain scoring of the BC were obtained via chart review. Patients underwent external beam radiotherapy (IMRT) to the pelvis and bilateral inguinal region (45 Gy in 25 fractions) followed by High Dose Rate Ir-192 interstitial brachytherapy in 5 fractions for a total dose of 25 Gy (22.5 - 27.5 Gy). Patients had a median age of 65 years (49-73) with tumors located in the lower vagina, near the BC and urethra. At the time of brachytherapy, in order to cover the HR-CTV, interstitial brachytherapy needles were placed within the BC structure with 58% (33% - 77%) of total interstitial needles placed within the bulbs of the BC. The mean pre-treatment volume of the BC was 16.6 cc (11.9 - 20.9 cc) and at brachytherapy was 12.66 cc (7.3 - 22.1 cc) with Table 1 summarizing radiation doses. At a median follow up of 19.6 months, all patients had a complete local response, with one patient deceased of metastatic disease. In the acute period, all patients reported severe pain in the clitoral glans region and dysuria that completely resolved after 2 years. Grade 1-2 vaginal stenosis occurred in all patients despite vaginal dilator usage. One patient reported decreased clitoral sensitivity and inability to achieve clitoral-mediated orgasm 5 months after radiotherapy. This study demonstrates that the BC receives a significant radiation dose during vaginal brachytherapy treatment which can cause clitoral pain and dysfunction. Further studies are needed to evaluate the dose response of the BC as well as explore methods to spare the organ during radiation therapy in order to minimize toxicity and preserve sexual function.

(144) Clitoral Anatomy and its Relation to Sexual Function after Apical Prolapse Repair using Pelvic MRI

Abstract Introduction The clitoris is the primary sexual organ involved in the physiological changes that occur during the female sexual response. Sparse research and contradictory evidence concerning clitoral anatomy and its role in female sexual function exist, especially in the context of pelvic floor disorders and their surgical correction. Comprehensive description of clitoral anatomy and how it relates to postoperative sexual function in women surgically treated for pelvic floor disorders is necessary to better understand the pathophysiological mechanisms of female sexual dysfunction following gynecologic surgery. Objective To identify characteristics of clitoral anatomy (size, location, shape) associated with female sexual function in women after vaginal hysterectomy with uterosacral ligament suspension (native tissue repair, NTR) or transvaginal mesh (VM) hysteropexy for uterovaginal prolapse. We hypothesized that a smaller clitoris and clitoral components would correlate with poorer sexual function. Methods In this ancillary study of women enrolled in a randomized clinical trial, 30–42-month postoperative axial MRIs of 82 women surgically treated (41 NTR, 41 VM) were obtained at rest. The clitoral components (glans, body, crura) and vestibular bulbs were segmented to create 3D models of the “clitoral complex” (Figure 1). Using these models and computational morphometry, clitoral dimensions and position were computed with respect to a 3D pelvic coordinate system (Figure 2). After aligning, normalizing (scaling), and establishing corresponding points between models, statistical shape modeling was performed via Principal Component Analysis (PCA) to identify/quantify significant modes of anatomic variation of the clitoris. Participant data included demographics, medical history, sexual activity status, and Pelvic Organ Prolapse/Incontinence Sexual Questionnaire, IUGA-Revised (PISQ-IR). The relationships between clitoral measurements/shape and sexual function were evaluated using Spearman rank correlation. Results For this group of mostly postmenopausal women (80/82 [97.6%]), median (min-max) age was 65.3 (47-79), 15/82 (18.3%) were sexually active (SA), and 21/82 (25.6%) were not sexually active (NSA) postoperatively (46/82 [56.1%] did not respond). Among SA women, a smaller glans width correlated with overall poorer sexual function (lower PISQ-IR mean score) (r=0.74, p=0.002), frequent feelings of shame/fear with leakage of urine/stool during sex (r=0.69, p=0.004), and low sexual arousal (r=0.61, p=0.02). A smaller glans height correlated with dyspareunia (r=-0.64, p=0.02) and less intense orgasms postoperatively (r=0.64, p=0.01). A smaller glans volume correlated with low sexual arousal (r=0.60, p=0.02) and a clitoral complex farther away from participants’ midline (midsagittal plane) correlated with greater negative impact of incontinence/prolapse on sex life (r=-0.66, p=0.007). Among NSA women, a clitoris farther away from participants’ midline was associated with dyspareunia as a strong reason for sexual inactivity (r=0.49, p=0.03). From the PCA, 11 significant modes of shape variation were found. For SA women, Modes 5 and 8 correlated with leakage of urine/stool during sex (r=-0.65, p=0.009) and dyspareunia (r=-0.59, p=0.04), respectively (Figure 3). For NSA women, Mode 4 correlated with dyspareunia as a strong reason for sexual inactivity (r=0.46, p=0.04) (Figure 3). Conclusions Poorer sexual function was associated with a smaller clitoral glans (width, height, volume) among SA women and a clitoral complex positioned farther away from participants’ midline in SA and NSA women following prolapse surgery. Disclosure Yes, this is sponsored by industry/sponsor: Boston Scientific Clarification Industry funding only - investigator initiated and executed study

(385) The Bulboclitoral Erectile Tissues: A Previously Unacknowledged Organ at Risk During Radiotherapy

Abstract Introduction Loss of sexual function can be a devastating side effect of the radiotherapy techniques used in the treatment of pelvic area tumors. Direct damage to the erectile tissues caused by off-target effects of radiation contributes to this loss of function. Advances in radiation techniques allow for greater tissue sparing, offering the potential to minimize tissue toxicity during treatments for pelvic cancers. In radiation oncology practice, specific attention is given to preserving sexual function in well characterized anatomic areas of male sexual function; however, preservation of clitoral structures involved in sexual function has not been well explored. Incorporating previously unacknowledged sexual structures such as the clitoris and vestibular bulbs (bulboclitoris for short) into radiotherapy treatment planning may improve our ability to preserve the function of these structures, including arousal and orgasm, after pelvic radiotherapy. Such an approach normalizes and affirms sexual pleasure as an important aspect of sexual health in cancer survivorship for women and gender-diverse persons. Objective We aim to explore the anatomic and radiologic characteristics of bulboclitoral sexual structures to shed light on their potential therapeutic applications in radiotherapy. Methods We evaluated the presence and configuration of the bulboclitoral erectile tissues and their proximity to other organs in a multi-modality study. The morphological characteristics were assessed in human cadaveric specimens using gross anatomic dissection and cross-sectioning as well as cross-sectional imaging using Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) (N=3). Results We present the CT, MRI, gross cross-sections, and 3D reconstruction of the bulboclitoral sexual structures. The presence and morphology of the female erectile tissues and adjacent structures are consistently demonstrated across modalities to inform anatomic delineation on radiotherapy planning scans. Conclusions The bulboclitoral erectile tissues are important structures in the pelvic region that have an essential role in sexual function. Attention to these previously unacknowledged structures has the potential to help improve patient outcomes in radiotherapy. In order to make this step, radiation oncologists can learn about the structures and their functions, and develop and apply advanced techniques to help preserve their integrity. Empowering radiotherapy clinicians with evidence for incorporating the anatomy, physiology and pathophysiology of organ function related to sexual pleasure in female persons with cancer provides an opportunity for tailored clinical decision-making and a more equitable distribution of advanced technologies that may preserve sexual function after cancer treatment. Disclosure No

Anatomic relationships of the clitoral body, bulbs of the vestibule, and urethra

Although recent studies have enhanced our understanding of the anatomy of the clitoris and its somatic innervation, less emphasis has been placed on the anatomic relationships of the clitoris to its surrounding structures. This study aimed to further characterize the gross and histologic relationships of the clitoris, vestibular bulbs, and urethra. Detailed dissections were performed in 30 unembalmed female cadavers. In 23 specimens, gross dissections were performed, and relationships of the clitoris, vestibular bulbs, and urethra were annotated. Histologic evaluation was performed in 7 specimens, in which tissues were harvested within 24 hours from death. Descriptive statistics were used for data analyses. The clitoral body consisted of 2 components, the proximal body and the distal body. The distal body was oriented ≤90° from the proximal body, forming an outer and inner angle at the inflection point. A "septumlike" arrangement of fibroconnective and vascular tissues was noted between the inner angle of the clitoral body and the urethra. Neurovascular bundles coursed laterally along the clitoral body and the surfaces of the crura and vestibular bulbs. The vestibular bulbs approached each other over the ventral surface of the urethra, at the commissure of the vestibular bulbs. Each bulb was separated by fibrous tissue and did not merge along the midline. The vestibular bulbs approximated the clitoral body, but the erectile tissue of the vestibular bulbs was separated from the corpora cavernosa of the clitoral body by the tunica albuginea. The erectile tissue of the vestibular bulbs abutted the ventrolateral walls of the urethra but was separated from the urethral mucosa by an indiscrete layer of erectilelike tissue with dense stroma. This study provided gross and histological confirmation of the relationships of the clitoris, vestibular bulbs, and urethra. Detailed knowledge of the anatomy of the clitoris is crucial for reducing surgical complications associated with periclitoral and distal urethral procedures, which may adversely affect sexual arousal and sexual function.

Clitoral Anatomy in the Feminist Literature: Vagina obscura: An anatomical voyage (2020) and Clitoral Conventions and Transgressions: Graphical representations in anatomy texts, c1900-1991 (1995).

O'Connell et al. proposed that the vestibular bulbs be renamed the "clitoral bulbs" because of their consistent relationship to the clitoris and inconsistent relationship to the vestibule. Normally such proposed esoteric changes in anatomical nomenclature would get little notice by anatomists, yet alone the general public; however, many subsequent articles and books placed this change in the context of centuries of male anatomists and physicians downplaying female sexual anatomy and sexuality. Most prominent is a 2022 book by Rachel Gross, Vagina Obscura: An Anatomical Voyage. Here we review this "Anatomical Voyage" and find author bias in omitting/including erroneous facts in this book. We also present a critique of a 1995 article that appeared in Feminist Studies; Graphical Representations in Anatomy Texts, c1900-1991. This article, which has been repeatedly cited in the clinical literature, asserts that between circa 1950-1980 anatomy textbooks purposely eliminated depicting/labeling the clitoris in illustrations because the authors of the textbooks were reflecting societal norms that de-emphasized the importance of the clitoris. Unfortunately, the methods used by Moore and Clarke are not replicable; and further, their conclusions were not justified because of clear bias in their description and depiction of the anatomy sources they review.

A first radiotherapy application of functional bulboclitoris anatomy, a novel female sexual organ-at-risk, and organ-sparing feasibility study.

The bulboclitoris (clitoris and vestibular bulbs) is the primary organ responsible for female sexual arousal and orgasm. Effects of radiotherapy on the bulboclitoris are unknown, as its structure/function has yet to be described in radiotherapy, and it overlaps only partially with the external genitalia structure. Our aim was to: describe bulboclitoris structure, function and delineation; compare volume of and dose delivered to the bulboclitoris vs external genitalia; and, compare bulboclitoris-sparing IMRT (BCS-IMRT) to standard IMRT (S-IMRT) to determine reoptimization feasibility. Our expert team (anatomist, pelvic radiologist, radiation oncologist) reviewed bulboclitoris anatomy and developed contouring guidance for radiotherapy. 20 female patients with anal cancer treated with chemoradiation were analyzed. Sexual organs at risk (OARs) included the external genitalia and the bulboclitoris. Volumes, dice similarity coefficients (DSCs) and dose received using S-IMRT were compared. Plans were reoptimized using BCS-IMRT. Dose-volume histograms (DVHs) for PTVs and all OARs were compared for BCS-IMRT vs S-IMRT. Bulboclitoris structure, function and delineation are described herein. The bulboclitoris occupies 20cc (IQR:12-24), largely distinct from the external genitalia (DSC <0.05). BCS-IMRT was superior to S-IMRT in reducing the dose to the bulboclitoris, with the greatest reductions in V30 and V40, with no significant changes in dose to other OARs or PTV 1/V95. The bulboclitoris can be contoured on planning imaging, largely distinct from the external genitalia. Compared with S-IMRT, BCS-IMRT dramatically reduced dose to the bulboclitoris in anal cancer planning. BCS-IMRT might safely reduce sexual toxicity compared with standard approaches. The structure and function of the bulboclitoris, the critical primary organ responsible for female sexual arousal and orgasm, has yet to be described in the radiotherapy literature. Structure, function and delineation of the bulboclitoris are detailed, delineation and bulboclitoris-sparing IMRT were feasible, and sparing reduces the dose to the bulboclitoris nearly in half in female patients receiving IMRT for anal cancer, warranting further clinical study.

Immediate vulvovaginal hematoma of the post-partum

Perigenital hematoma a rare cause of postpartum hemorrhage. It corresponds to the detachment of the paravaginal, paracervical or parametrial connective tissue by vascular lesions generally due to direct trauma during childbirth. We report a case of a 19-year-old female patient who presented painful swelling of the vulva after vaginal delivery. The examination found a patient with a pale face and stable vital constants. Inspection of the vulva reveals a purplish-pink swelling of the right hemivulva of 20/14 cm (A), reaching the inguinal fold, the large gluteal fold in the mount of venus by compressing the left lip inside and the vaginal orifice. The deep vaginal examination showed an extension of the hematoma to the right lateral wall of the vagina and two tears (at the lateral cul de sac and 2 cm from the vestibular bulb). The management was surgical and medical by hemostatic sutures after evacuation of a 700ml hematoma and we repaired the episiotomy. The patient was given antibiotics and local antiseptic. No recurrence was noticed in the post-partum.

The new etiology and surgical therapy of stress urinary incontinence in women

ObjectivesTo determine the subjective and objective cure rate of a urethral stabilization procedure (USP) for stress urinary incontinence (SUI) in women; to describe this new surgical intervention; to record its potential complications; to establish the SUI etiology. Study DesignThe author conducted a prospective case series study in ambulatory settings and under local anesthesia. Thirty-four consecutive women with uncomplicated SUI subjected to USP, which was performed by reconstructing site-specific defects within the urethral stabilizing mechanism (USM) and using no surgical slings, meshes or absorbable sutures. The paravaginal defect(s) was repaired by transvaginal approach. The endopelvic fascia was sharply separated from the ventral perineal membrane (VPM) just above the anterior urethral meatus. The vestibular bulbs sharply dissected from VPM and advance upwards. The VPM defect(s) reconstructed and vestibular bulbs placed back to the original location. The access to the peri- and the para-urethral region was created by making a lateral vertical incision, aside from the lateral urethral meatus and defects were repaired. The suburethral transverse incision was made beneath the urethral meatus and the stratum-by-stratum surgical dissection conducted until the lateral vaginourethral ligament is visualized bilaterally. The defect(s) within the vaginourethral ligaments was surgically reconstructed, and the vaginal wall repaired. The primary outcome measured subjective and objective cure rates, and the secondary outcome measured the occurrence of potential complications. The five-year postoperative follow-up was conducted. ResultsTwo out of thirty-four patients dropped-out from the study. The USP performed without difficulties, and no severe complication observed. One-subject developed superficial wound separation (3.1 %) and one-subject (3.1 %) developed urinary urge incontinence at the 5-postoperative-year. At 60-month follow-up subjective and objective cure rates were a 92 % and an 88 % respectively. ConclusionsThe urethral stabilization procedure yields a high degree of subjective and objective cure rates without severe complications and is a well-tolerated operation by women. The urethral stabilization procedure is a simple, easy to implement, and reproducible method for uncomplicated stress urinary incontinence in women. Site-specific defects within the urethral stabilizing mechanism constitute the etiology of the stress urinary incontinence in women.

Anatomy, histology, and nerve density of clitoris and associated structures: clinical applications to vulvar surgery

A precise understanding of structures comprising the female external genitalia is essential in obstetric and gynecologic practice. To further characterize the anatomy, histology, and nerve density of the clitoris and associated structures, and to provide clinical correlations to vulvar surgery. Unembalmed female cadavers were examined. The length and width of the body, glans, and crura of the clitoris were measured. Distances from the glans to the urethra and from the dorsal surface of the clitoral body to the mid pubic arch were recorded. The path of the dorsal nerve of the clitoris was examined, and the nerve width was measured as it emerged from the lateral surface of crura and at the distal clitoral body. Distances from where the dorsal nerve emerged from the perineal membrane to the posterior surface of the membrane and to mid pubic arch were measured. Connective tissue layers associated with the clitoris were examined. Tissue was harvested from additional unembalmed cadavers, and nerve density of the labia minora, glans, and clitoral body were analyzed. Histological examination was performed on vulvar structures to clarify tissue composition. Descriptive statistics were used for data analyses. A total of 27 cadavers (aged 48-96 years) were examined, 22 grossly and 5 histologically. The median length and width of clitoral body were 29 mm (range, 13-59 mm) and 9 mm (range, 5-14 mm), respectively. The glans was 8 mm (range, 5-12 mm) long and 4 mm (range, 3-10 mm) wide. The length of the crura was 50 mm (range, 25-68 mm), and the width at the anterior portion was 9 mm (range, 2-13 mm). The closest distance from the glans to the urethra was 25 mm (range, 14-37 mm) and from the clitoral body to the mid pubic arch was 29 mm (range, 14-46 mm). The widths of the dorsal nerve at the lateral crura and at the distal clitoral body were 3 mm (range, 2-4 mm) and 1 mm (range, 1-2 mm), respectively. The distance from the dorsal nerve as it emerged from the perineal membrane to the mid pubic arch was 34 mm (range, 20-48 mm) and to the posterior surface of the membrane was 20 mm (range, 8-31 mm). The dorsal nerve and artery of the clitoris coursed adjacent to the medial surface of the inferior pubic ramus surrounded by a dense fibrous capsule adherent to the periosteum. The nerve and artery then coursed deep to dense connective tissue layers, which were contiguous with the suspensory ligament and fascia of the clitoris. Histologic examination revealed the presence of erectile tissue in the clitoral body, crura, and vestibular bulbs, but such tissue was absent in the glans and labia minora. Nerve density analysis revealed statistically significant greater density in the dorsal compared with ventral half of the clitoral body. Although not statistically significant, there was increased nerve density in the distal compared to the proximal half of the labia minora. Precise knowledge of clitoral anatomy and associated neurovascular structures is essential to safely complete partial vulvectomies, clitoral and vulvar reconstructive procedures, anti-incontinence surgeries, and repair of obstetric lacerations. Understanding the range of anatomic variations and awareness of the areas of increased nerve density is important during counseling and surgical planning. Although the dorsal nerve of the clitoris courses deep to dense connective tissue layers, inadvertent injury may occur in the setting of deep dissection or suture placement. The dorsal nerve seems most vulnerable with surgical entry or lacerations that extend from the midline of the prepuce to the inferior pubic rami.

Reproductive Tract Histology in South American Fur Seal Pups (Arctophoca australis).

In the present study, a detailed histological description of the female reproductive tract of South American fur seal (Arctophoca australis) pups has been conducted. The uterine tube was covered by cuboidal to columnar epithelium; nerve fibers were present in the mesosalpinx and beneath the muscular layer. The uterus was bipartitus; the endometrial surface of the horns was lined by a simple cuboidal or columnar epithelium with deep tubular glands; caudally ("the transition area"), the epithelium changed to pseudostratified columnar, few tubular glands were present and the myometrium increased in width. A bistratified epithelium internally coated the uterine body, whereas it changed to cylindrical stratified epithelium with a highly vascularized lamina propria and a strong muscular layer in the cervix; no endometrial glands were observed in this region. From the transition area of the uterus to the vagina there were several nerve fibers and ganglia belonging to the uterovaginalis plexus. In the vestibule, hymenal folds were poorly developed; adnexa structures included the major vestibular glands and a neurovascular structure similar to the vestibular bulb. Minor vestibular glands were associated with the clitoris. The skin of the perineum was lined by a keratinized stratified epithelium, pigmented, with sebaceous glands, sweat glands and hair follicles. This is the first detailed histological description of the reproductive tract of South American fur seal pups, including the glandular adnexa and nerve structures. These results contribute to the reproductive biology in Pinniped species, and give a better understanding of the utero-placental perfusion mechanism during diving. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:600-613, 2017. © 2016 Wiley Periodicals, Inc.

Anatomy of sex: Revision of the new anatomical terms used for the clitoris and the female orgasm by sexologists.

Sexual medicine experts and sexologists must spread certainties on the biological basis of the female orgasm to all women, not hypotheses or personal opinions. Therefore, they must use scientific anatomical terminology. The anatomy of the clitoris and the female orgasm are described in textbooks, but some researchers have proposed a new anatomical terminology for the sexual response in women. The internal/inner clitoris does not exist: the entire clitoris is an external organ. The clitoris is not composed of two arcs but of the glans, body, and crura or roots. "Clitoral bulbs" is an incorrect term from an embryological and anatomical viewpoint: the correct term is "vestibular bulbs." The bulbocavernosus muscles are implicated in inferior vaginismus, while the pubovaginal muscle is responsible for superior vaginismus. The clitoral or clitoris-urethro-vaginal complex has no embryological, anatomical and physiological support: the vagina has no anatomical relationship with the clitoris, and the clitoris is a perineal organ while the supposed G-spot is in the pelvic urethra. G-spot/vaginal/clitoral orgasm, vaginally activated orgasm, and clitorally activated orgasm, are incorrect terms: like "male orgasm," "female orgasm" is the correct term. The "vaginal" orgasm that some women report is always caused by the surrounding erectile organs (triggers of female orgasm). The male penis cannot come in contact with the venous plexus of Kobelt or with the clitoris during vaginal intercourse. Also, female ejaculation, premature ejaculation, persistent genital arousal disorder (PGAD), periurethral glans, vaginal-cervical genitosensory component of the vagus nerve, and G-spot amplification, are terms without scientific basis. Female sexual satisfaction is based on orgasm and resolution: in all women, orgasm is always possible if the female erectile organs, i.e. the female penis, are effectively stimulated during masturbation, cunnilingus, partner masturbation, or during vaginal/anal intercourse if the clitoris is simply stimulated with a finger. Clin. Anat. 28:293-304, 2015. © 2014 Wiley Periodicals, Inc.

Anatomy and physiology of the clitoris, vestibular bulbs, and labia minora with a review of the female orgasm and the prevention of female sexual dysfunction.

This review, with 21 figures and 1 video, aims to clarify some important aspects of the anatomy and physiology of the female erectile organs (triggers of orgasm), which are important for the prevention of female sexual dysfunction. The clitoris is the homologue of the male's glans and corpora cavernosa, and erection is reached in three phases: latent, turgid, and rigid. The vestibular bulbs cause "vaginal" orgasmic contractions, through the rhythmic contraction of the bulbocavernosus muscles. Because of the engorgement with blood during sexual arousal, the labia minora become turgid, doubling or tripling in thickness. The corpus spongiosum of the female urethra becomes congested during sexual arousal; therefore, male erection equals erection of the female erectile organs. The correct anatomical term to describe the erectile tissues responsible for female orgasm is the female penis. Vaginal orgasm and the G-spot do not exist. These claims are found in numerous articles that have been written by Addiego F, Whipple B, Jannini E, Buisson O, O'Connell H, Brody S, Ostrzenski A, and others, have no scientific basis. Orgasm is an intense sensation of pleasure achieved by stimulation of erogenous zones. Women do not have a refractory period after each orgasm and can, therefore, experience multiple orgasms. Clitoral sexual response and the female orgasm are not affected by aging. Sexologists should define having sex/love making when orgasm occurs for both partners with or without vaginal intercourse.

Neural Supply to the Clitoris: Immunohistochemical Study with Three‐Dimensional Reconstruction of Cavernous Nerve, Spongious Nerve, and Dorsal Clitoris Nerve in Human Fetus

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. 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. 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. Pelvic-perineal nerve location and type were evaluated qualitatively. 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. "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.

Perineal body anatomy in living women: 3-dimensional analysis using thin-slice magnetic resonance imaging

The objective of the study was to describe a framework for visualizing the perineal body's complex anatomy using thin-slice magnetic resonance (MR) imaging. Two millimeter thick MR images were acquired in 11 women with normal pelvic support and no incontinence/prolapse symptoms. Anatomic structures were analyzed in axial, sagittal, and coronal slices. Three-dimensional (3-D) models were generated from these images. Three distinct perineal body regions are visible on MR imaging: (1) a superficial region at the level of the vestibular bulb, (2) a midregion at the proximal end of the superficial transverse perineal muscle, and (3) a deep region at the level of the midurethra and puborectalis muscle. Structures are best visualized on axial scans, whereas craniocaudal relationships are appreciated on sagittal scans. The 3-D model further clarifies interrelationships. Advances in MR technology allow visualization of perineal body anatomy in living women and development of 3-D models that enhance our understanding of its 3 different regions: superficial, mid, and deep.

Penislike clitorises with megalourethras in nonvirilized female fetuses and a newborn. A histopathologic study and its bearing on their pathogenesis

Purpose The aim of the study was to analyze the microstructure of penislike clitorises in female pseudohermaphroditism in relation to their pathogenesis. Methods Penislike clitorises from 2 fetuses and 1 newborn with anorectal malformations and multiple other caudal anomalies and 1 fetus with phallic urethra duplication were histologically examined in toto. Results The penislike clitorises revealed basically female features in the histogenesis of the corpora cavernosa and glans and in the absence of penile raphe, septum, fasciae, and periurethral glands. In 2 cases, the “phallic urethra” was completely surrounded by a single corpus cavernosum and in 3 cases by a circular glans. Labia minora and vestibular bulbs had not developed in 3 cases. The urethras had transformed into fusiform or scaphoid megalourethras with stenotic meatuses in 3 specimens and an extra orifice in the fourth specimen. Conclusions Penislike clitorises in female pseudohermaphroditism show a fundamental dysgenesis of major structural elements. The pattern favors the hypothesis of an early error in the formation of the cloacal membrane and adjacent cloaca in embryos between 26 and 29 days postovulation that may lead to dysregulation of molecular developmental interactions during the following formation of the genital tubercle.

Anatomy of the perineal membrane as seen in magnetic resonance images of nulliparous women

Recent cadaver research demonstrates the perineal membrane's ventral and dorsal portions and close relationship to the levator ani muscle. This study seeks to show these relationships in women by magnetic resonance (MR) images. The subjects were 20 asymptomatic nulliparous women with normal pelvic examinations. MR images were acquired in multiple planes. Anatomical relationships from cadaver studies were examined in these planes. In the coronal plane the ventral perineal membrane forms an interconnected complex with the compressor urethrae, vestibular bulb, and levator ani. The dorsal part connects the levator ani and vaginal side wall via a distinct band to the ischiopubic ramus. In the sagittal plane the parallel position of perineal membrane and levator ani are seen. The perineal membrane's anatomical features can be seen in women with MR. The close relationship between the perineal membrane and levator ani is evident.

Structure of the Perineal Membrane in Females

To re-examine the anatomy of the perineal membrane and its anatomical relationships in whole-pelvis and histologic serial section as well as gross anatomical dissection. Serial trichrome-stained histologic sections of five female pelvic specimens (0-37 years old) were examined. Specimens included the urethra, perineal membrane, vagina, and surrounding structures. Macroscopic whole-pelvis sections of three adults, 28-56 years of age, in axial, sagittal, and coronal sections were also studied. Dissections of six female cadavers, 48-90 years of age, were also performed. The perineal membrane is composed of two regions, one dorsal and one ventral. The dorsal portion consists of bilateral transverse fibrous sheets that attach the lateral wall of the vagina and perineal body to the ischiopubic ramus. This portion is devoid of striated muscle. The ventral portion is part of a solid three-dimensional tissue mass in which several structures are embedded. It is intimately associated with the compressor urethrae and the urethrovaginal sphincter muscle of the distal urethra with the urethra and its surrounding connective. In this region the perineal membrane is continuous with the insertion of the arcus tendineus fascia pelvis. The levator ani muscles are connected with the cranial surface of the perineal membrane. The vestibular bulb and clitoral crus are fused with the membrane's caudal surface. The structure of the perineal membrane is a complex three-dimensional structure with two distinctly different dorsal and ventral regions; not a simple trilaminar sheet with perforating viscera.