Pre- and post-LEEP: analysis of the female urogenital tract microenvironment and its association with sexual dysfunction.

Background: The loop electrosurgical excision procedure (LEEP) to treat cervical dysplasia (CD) is known to alter the cervical microbiota, the community of bacteria that play a central role in female genital health. Perturbations to the microbiota of the female urogenital tract (FUT), including the urethra, vagina, and cervix, have been linked with symptoms of sexual dysfunction (SD), though correlations among LEEP, the microenvironment, and SD have not yet been described. Aims: To characterize the FUT microbiota before and after LEEP and investigate possible associations with SD. Methods: Females undergoing LEEP for CD were recruited to participate in the study. Urinary samples and vaginal and cervical swabs were collected immediately before and 3 months after treatment. Bacterial communities were characterized by 16S rRNA next-generation sequencing. Self-report surveys assessing demographics, medical history, and sexual function were completed at the same intervals. Outcomes: Microbiota taxonomy and Female Sexual Function Index (FSFI) scores. Results: Alpha diversity revealed a significant decrease in species richness in the FUT microbiota post-LEEP. Beta diversity demonstrated significant differences among the cervical, urinary, and vaginal microenvironments pre- and post-LEEP. Lactobacillus spp were the dominant microbial genus in the cervical microenvironment pre- and post-LEEP. Although the vaginal and urinary microenvironments were characterized by Prevotella pre-LEEP, they were colonized by Lactobacillus post-LEEP. Following LEEP, some participants experienced a significant increase in proinflammatory bacteria, including the genera Gardnerella, Megasphaera, Sneathia, Parvimonas, and Peptostreptococcus. Others experienced significant decreases in inflammatory and protective bacteria post-LEEP, including Butyricicoccus, Terriporobacter, Intestinimonas, and Negativibacillus. Overall there were no significant changes in pre- and post-LEEP FSFI scores. However, post-LEEP FSFI scores were seemingly associated with changes in inflammatory bacteria in some participants. Clinical Implications: There is an overall reduction in FUT microbiota dysbiosis post-LEEP. However, we show variability as some participants experienced persistent dysbiosis of FUT microbiota and elevated FSFI scores, suggesting that therapies to treat dysbiosis of FUT microbiota may reduce FSFI scores, thereby improving SD symptoms. Strengths and Limitations: We demonstrate novel associations among urogenital sites, microbiota changes, LEEP, and SD. The small sample size and inability of species classification are limitations. Conclusion: Diverse inflammatory microbiota characterizes CD in the FUT, and LEEP mostly returns microenvironments to a healthy state. However, some participants have persistent inflammatory bacteria post-LEEP, suggesting a non-uniform healing response. This study provides an impetus for future longitudinal studies to monitor and restore FUT microenvironments post-LEEP, aimed at mitigating postoperative SD symptoms.

Molecular characterization of human peripheral nerves using desorption electrospray ionization mass spectrometry imaging.

Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) is a molecular imaging method that can be used to elucidate the small-molecule composition of tissues and map their spatial information using two-dimensional ion images. This technique has been used to investigate the molecular profiles of variety of tissues, including within the central nervous system, specifically the brain and spinal cord. To our knowledge, this technique has yet to be applied to tissues of the peripheral nervous system (PNS). Data generated from such analyses are expected to advance the characterization of these structures. The study aimed to: (i) establish whether DESI-MSI can discriminate the molecular characteristics of peripheral nerves and distinguish them from surrounding tissues and (ii) assess whether different peripheral nerve subtypes are characterized by unique molecular profiles. Four different nerves for which are known to carry various nerve fiber types were harvested from a fresh cadaveric donor: mixed, motor and sensory (sciatic and femoral); cutaneous, sensory (sural); and autonomic (vagus). Tissue samples were harvested to include the nerve bundles in addition to surrounding connective tissue. Samples were flash-frozen, embedded in optimal cutting temperature compound in cross-section, and sectioned at 14 µm. Following DESI-MSI analysis, identical tissue sections were stained with hematoxylin and eosin. In this proof-of-concept study, a combination of multivariate and univariate statistical methods was used to evaluate molecular differences between the nerve and adjacent tissue and between nerve subtypes. The acquired mass spectral profiles of the peripheral nerve samples presented trends in ion abundances that seemed to be characteristic of nerve tissue and spatially corresponded to the associated histology of the tissue sections. Principal component analysis (PCA) supported the separation of the samples into distinct nerve and adjacent tissue classes. This classification was further supported by the K-means clustering analysis, which showed separation of the nerve and background ions. Differences in ion expression were confirmed using ANOVA which identified statistically significant differences in ion expression between the nerve subtypes. The PCA plot suggested some separation of the nerve subtypes into four classes which corresponded with the nerve types. This was supported by the K-means clustering. Some overlap in classes was noted in these two clustering analyses. This study provides emerging evidence that DESI-MSI is an effective tool for metabolomic profiling of peripheral nerves. Our results suggest that peripheral nerves have molecular profiles that are distinct from the surrounding connective tissues and that DESI-MSI may be able to discriminate between nerve subtypes. DESI-MSI of peripheral nerves may be a valuable technique that could be used to improve our understanding of peripheral nerve anatomy and physiology. The ability to utilize ambient mass spectrometry techniques in real time could also provide an unprecedented advantage for surgical decision making, including in nerve-sparing procedures in the future.

Three-dimensional reconstruction of the innervation of the female pelvis: A review of current methods.

The three-dimensional (3D) reconstruction of tissues is a valuable approach for elucidating the anatomy of nerves and plexuses, which are often microscopic in nature and therefore difficult to fully appreciate using gross dissection approaches alone. A common workflow which can be used to generate such 3D models has yet to be comprehensively described. This study aimed to review 3D reconstruction methodologies and findings related to human female pelvic innervation to determine whether there is an optimal methodology and identify the limitations of these approaches. A comprehensive literature review was conducted using keywords including 3D reconstruction, human female pelvic nerves, and innervation. Twenty relevant articles published between 2003 and 2019 were selected for review. The 3D reconstruction of female pelvic innervation generally follows two workflows involving either immunohistochemistry (IHC) (n = 16) or magnetic resonance imaging (MRI) (n = 4). There were commonalities among the general steps reported for 3D tissue reconstruction across these two imaging methodologies. Notably, there was some variability in study methodology across the studies reviewed, suggesting there is not a clear best practice for the reconstruction of these tissues. Information that generates 3D mapping of innervation has important clinical applications, such as informing and optimizing surgical approaches to avoid damage to local innervation. IHC and MRI-based approaches are both feasible for the reconstruction of pelvic innervation, though there are advantages and disadvantages to both. Information from this review can be used to help inform the development of 3D models of female pelvic innervation in the future.

Innervation of the human vulvar vestibule: A comprehensive review.

Pain of the vulvar vestibule, including provoked vestibulodynia, is prevalent among women, yet challenging to treat due to its multifactorial etiology. Recent evidence indicates a neuroproliferative subtype in which hypersensitivity of the vulvar vestibule is due, in part, to hyperinnervation. Detailed knowledge regarding the innervation of the vulvar vestibule is crucial to understanding and treating pain conditions impacting this region. The purpose of this review is to consolidate the current evidence regarding the innervation of the human vulvar vestibule and discuss the implications of this innervation for pathological conditions affecting this tissue. A comprehensive review of the literature was conducted using keywords including vulvar vestibule, innervation, and vestibulodynia to identify articles concerning the innervation of the vulvar vestibule. Fifteen studies published between 1998 and 2017 were reviewed. Evidence from immunohistochemical investigations support that the vulvar vestibule has nociceptive, mechanosensory, sympathetic, and parasympathetic innervation. In pathological samples, hyperinnervation supports the neuroproliferative etiology of provoked vestibulodynia. Additionally, there is some evidence supporting the role of the pudendal nerve in vulvar vestibule innervation, although no cadaveric studies have been reported to date. Progress has been made in our understanding of the innervation of the vulvar vestibule, though further research into the origin of sensory and autonomic innervation of this region is needed. Advancing the knowledge of vulvar vestibule innervation is crucial towards improving our understanding of the function of this tissue, in addition to informing the etiology and management of pain syndromes impacting this region.

The human cervix: Comprehensive review of innervation and clinical significance.

Detailed knowledge regarding the innervation and histology of the human cervix is crucial given the surgical removal of this tissue for conditions such as cervical dysplasia. Recent evidence implicates the cervix in the sexual response, making it pertinent to characterize this region to elucidate its role. Despite this, literature describing the overall innervation of the cervix from anatomical and histological perspectives is lacking. The aim of this review was to consolidate descriptions pertaining to human cervix innervation and discuss possible mechanisms of dysfunction, as an unintended result of cervix removal. A detailed literature search of relevant articles describing human cervix innervation was conducted. 1597 articles were screened based on the keywords searched. Only 16 articles, containing information regarding specific evidence of the innervation of the human cervix, were included and categorized based on parameters of innervation (method, type, location). The published evidence demonstrates that the human cervix has sympathetic, parasympathetic, and sensory innervation, but does not characterize changes after surgical procedures. Despite the gaps in knowledge, it is relevant that associations linking clinical procedures, involving cervical removal and adverse sexual health outcomes, become an important focus for discussions between physicians and patients. Future work is needed to better detail the affected innervation as well as the neural pathway-specific relationship to symptoms of sexual dysfunction.