Molecular Landscape of Pelvic Organ Prolapse Provides Insights into Disease Etiology.

Pelvic organ prolapse (POP) represents a major health care burden in women, but its underlying pathophysiological mechanisms have not been elucidated. We first used a case-control design to perform an exome chip study in 526 women with POP and 960 control women to identify single nucleotide variants (SNVs) associated with the disease. We then integrated the functional interactions between the POP candidate proteins derived from the exome chip study and other POP candidate molecules into a molecular landscape. We found significant associations between POP and SNVs in 54 genes. The proteins encoded by 26 of these genes fit into the molecular landscape, together with 43 other POP candidate molecules. The POP landscape is located in and around epithelial cells and fibroblasts of the urogenital tract and harbors four interacting biological processes-epithelial-mesenchymal transition, immune response, modulation of the extracellular matrix, and fibroblast function-that are regulated by sex hormones and TGFB1. Our findings were corroborated by enrichment analyses of differential gene expression data from an independent POP cohort. Lastly, based on the landscape and using vaginal fibroblasts from women with POP, we predicted and showed that metformin alters gene expression in these fibroblasts in a beneficial direction. In conclusion, our integrated molecular landscape of POP provides insights into the biological processes underlying the disease and clues towards novel treatments.

The efficacy of botulinum toxin a injections in pelvic floor muscles in chronic pelvic pain patients: a systematic review and meta-analysis.

INTRODUCTION AND HYPOTHESIS: Chronic pelvic pain (CPP) is a common multifactorial condition affecting 6 to 27% of women aged 18-50 years worldwide. This study was conducted to review and meta-analyse the current literature on the reduction of chronic pelvic pain after botulinum toxin A (BTA) injection. METHOD: In July 2021 we performed a systematic search in PubMed and EMBASE to assess the benefits of BTA injection in pelvic floor muscles in women with chronic pelvic pain. Primary outcome was reduction in visual analogue scale (VAS) after treatment. Secondary outcomes evaluated were: reduction of dyspareunia, pelvic floor resting pressure and quality of life. Identified reports were assessed on quality of reporting and risk of bias. Standardized mean difference (SMD) was used to combine and analyse outcomes of the included studies. RESULTS: Eight studies with 289 participants were considered eligible to be included in this systematic review and meta-analysis. After recalculating SMD into VAS scores (0-100), long-term follow-up (24-26 weeks) showed a significant 15-point improvement in VAS scores (95% CI: 8.8-21.5) for non-menstrual pelvic pain and a 13-point improvement (95% CI: 2.1-24.0) for dyspareunia. BTA injection had a significant effect on pelvic floor resting pressure and quality of life. CONCLUSION: There is limited scientific evidence on the effectiveness of BTA injections in pelvic floor muscles in women with chronic pelvic pain. The available studies show that BTA injections significantly reduce pain levels and improve quality of life at 6 months follow-up. PROSPERO ID: CRD42018105204.

Extracellular Matrix Stiffness and Composition Regulate the Myofibroblast Differentiation of Vaginal Fibroblasts.

Fibroblast to myofibroblast differentiation is a key feature of wound-healing in soft tissues, including the vagina. Vaginal fibroblasts maintain the integrity of the vaginal wall tissues, essential to keep pelvic organs in place and avoid pelvic organ prolapse (POP). The micro-environment of vaginal tissues in POP patients is stiffer and has different extracellular matrix (ECM) composition than healthy vaginal tissues. In this study, we employed a series of matrices with known stiffnesses, as well as vaginal ECMs, in combination with vaginal fibroblasts from POP and healthy tissues to investigate how matrix stiffness and composition regulate myofibroblast differentiation in vaginal fibroblasts. Stiffness was positively correlated to production of α-smooth muscle actin (α-SMA). Vaginal ECMs induced myofibroblast differentiation as both α-SMA and collagen gene expressions were increased. This differentiation was more pronounced in cells seeded on POP-ECMs that were stiffer than those derived from healthy tissues and had higher collagen and elastin protein content. We showed that stiffness and ECM content regulate vaginal myofibroblast differentiation. We provide preliminary evidence that vaginal fibroblasts might recognize POP-ECMs as scar tissues that need to be remodeled. This is fundamentally important for tissue repair, and provides a rational basis for POP disease modelling and therapeutic innovations in vaginal reconstruction.

Regenerative medicine as a therapeutic option for fecal incontinence: a systematic review of preclinical and clinical studies.

BACKGROUND: Fecal incontinence is the uncontrollable loss of stool and has a prevalence of around 7-15%. This condition has serious implications for patients' quality of life. Current treatment options show unsatisfactory results. A novel treatment option is therefore needed. OBJECTIVE: This systematic review aims to perform a quality assessment and to give a critical overview of the current research available on regenerative medicine as a treatment for fecal incontinence. STUDY DESIGN: A systematic search strategy was applied in PubMed, Cochrane Library, EMBASE, MEDLINE, Web of Science, and Cinahl from inception until March of 2018. Studies were found relevant when the animals or patients in the studied group had objectively determined or induced fecal incontinence, and the intervention must have used any kind of cells, stem cells, or biocompatible material, with or without the use of trophic factors. Studies were screened on title and consecutively on abstract for relevance by 2 independent investigators. The risk of bias of preclinical studies was assessed using the SYstematic Review Centre for Laboratory animal Experimentation risk of bias tool for animal studies, and for clinical studies the Cochrane risk of bias tool for randomized trials was used. RESULTS: In all, 34 preclinical studies and 5 clinical studies were included. Animal species, type of anal sphincter injury, intervention, and outcome parameters were heterogenous. Therefore, a meta-analysis could not be performed. The overall risk of bias of the included studies was high. CONCLUSION: The efficacy of regenerative medicine to treat fecal incontinence could not be determined due to the high risk of bias and heterogenicity of the available preclinical and clinical studies. The findings of this systematic review may result in improved study design of future studies, which could help the translation of regenerative medicine to the clinic as an alternative to current treatments for fecal incontinence.

Management of post-midurethral sling voiding dysfunction. International Urogynecological Association research and development committee opinion.

Voiding dysfunction following midurethral sling procedures is not a rare event. There is no current consensus regarding management of this complication. Although it is often transient and self-limiting, chronic post-midurethral sling voiding dysfunction may lead to irreversible changes affecting detrusor function. Initial management includes intermittent catheterization, and addressing circumstantial factors interfering with normal voiding, such as pain. Early sling mobilization often resolves the dysfunction, and is associated with minimal morbidity. Sling incision or excision at a later stage, although fairly effective, could be associated with recurrence of stress urinary incontinence. There is insufficient evidence to justify urethral dilatation in this context.

Obesity and pelvic organ prolapse.

PURPOSE OF REVIEW: The purpose of this review is to review the data on the relationship of obesity and pelvic organ prolapse (POP). This review is timely and relevant as the prevalence of obesity is increasing worldwide, and it is an important risk factor to consider in counseling women on management of prolapse symptoms and outcomes for surgical treatment. RECENT FINDINGS: The main findings in the literature include: Obesity is increasing worldwide and impacts health, social life, work and healthcare costs. Elevated BMI is an important lifestyle factor affecting pelvic prolapse. The most probable mechanism of POP development among obese women is the increase in intra-abdominal pressure that causes weakening of pelvic floor muscles and fascia. Obesity is associated with significant pelvic floor symptoms and impairment of quality of life (QOL). Weight loss is likely not associated with anatomic improvement, but may be associated with prolapse symptom improvement. Weight loss should be considered a primary option in obese women for its beneficial effects on multiple organ systems and reducing pelvic floor disorder (PFD) symptoms. Although the operation time in obese women is significantly longer than in healthy weight women, the complication rate of surgery has not been shown to be increased compared to nonobese patients, regardless of route of surgery. There are data to support the vaginal approach in obese women. Some studies have shown that women with high body weight are associated with an increase in the risk for both anatomical and functional recurrence, and other studies have shown no difference. SUMMARY: Obesity is a prevalent modifiable condition that impacts PFDs including pelvic prolapse. Patients should be counseled using clinical judgment, knowledge of the literature and with the goal of improving QOL.

Toward a new generation of pelvic floor implants with electrospun nanofibrous matrices: A feasibility study.

OBJECTIVE: The use of knitted, polypropylene meshes for the surgical treatment of pelvic organ prolapse (POP) is frequently accompanied by severe complications. Looking for alternatives, we studied the potential of three different electrospun matrices in supporting the adhesion, proliferation, and matrix deposition of POP and non-POP fibroblasts, the most important cells to produce extracellular matrix (ECM), in vitro. STUDY DESIGN: We electrospun three commonly used medical materials: nylon; poly (lactide-co-glycolide) blended with poly-caprolactone (PLGA/PCL); and poly-caprolactone blended with gelatin (PCL/Gelatin). The matrices were characterized for their microstructure, hydrophilicity, and mechanical properties. We seeded POP and non-POP fibroblasts from patients with POP and we determined cellular responses and ECM deposition. RESULTS: All matrices had >65% porosity, homogenous microstructures, and close to sufficient tensile strength for pelvic floor repair: 15.4 ± 3.3 MPa for Nylon; 12.4 ± 1.6 MPa for PLGA/PCL; and 3.5 ± 0.9 MPa for PCL/Gelatin. Both the POP and non-POP cells adhered to the electrospun matrices; they proliferated well and produced ample ECM. Overall, the best in vitro performance appeared to be on nylon, presumably because this was the most hydrophilic material with the thinnest fibers. CONCLUSION: Electrospun nanofibrous matrices show feasible mechanical strength and great biocompatibility for POP and non-POP fibroblasts to produce their ECM in vitro and, thus, may be candidates for a new generation of implants for pelvic floor repair. Further studies on electrospun nanofibrous matrices should focus on mechanical and immunological conditions that would be presented in vivo. Neurourol. Urodynam. 36:565-573, 2017. © 2016 Wiley Periodicals, Inc.

Vaginal Fibroblastic Cells from Women with Pelvic Organ Prolapse Produce Matrices with Increased Stiffness and Collagen Content.

Pelvic organ prolapse (POP) is characterised by the weakening of the pelvic floor support tissues, and often by subsequent prolapse of the bladder outside the body, i.e. cystocele. The bladder is kept in place by the anterior vaginal wall which consists of a dense extracellular matrix rich in collagen content that is maintained and remodelled by fibroblastic cells, i.e. fibroblasts and myofibroblasts. Since altered matrix production influences tissue quality, and myofibroblasts are involved in normal and pathological soft tissue repair processes, we evaluated matrix production of cells derived from pre- and post-menopausal POP and non-POP control anterior vaginal wall tissues. Results showed that cells from postmenopausal POP women deposited matrices with high percentage of collagen fibres with less anisotropic orientation and increased stiffness than those produced by controls. There was a transient increase in myofibroblastic phenotype that was lost after the peak of tissue remodelling. In conclusion, affected fibroblasts from postmenopausal prolapsed tissues produced altered matrices in vitro compared to controls. Such aberrant altered matrix production does not appear to be a consequence of abnormal phenotypical changes towards the myofibroblastic lineage.

Variation in the practice of laparoscopic sacrohysteropexy and laparoscopic sacrocolpopexy for the treatment of pelvic organ prolapse: a Dutch survey.

INTRODUCTION AND HYPOTHESIS: Laparoscopic techniques for pelvic organ prolapse surgery using mesh are gaining interest. A standard approach or published guideline for the laparoscopic sacrohysteropexy (LSH) or laparoscopic sacrocolpopexy (LSC) is lacking. The purpose of this study is to assess the variation between Dutch gynecologists in executing LSH and LSC. METHODS: A questionnaire was developed to evaluate the technique of LSH and LSC. All members of the Dutch Society for Gynecological Endoscopy and Minimally Invasive Surgery and the Dutch Society for Urogynecology were invited by email to participate in a web-based survey. RESULTS: With 357 respondents, the response rate was 71%. Of the respondents, a total of 49 gynecologists (13.7%) perform LSH and/or LSC. Gynecologists who perform both procedures use the same surgical technique for LSH and LSC. There are variations among gynecologists on several key points such as the level of dissection along the anterior and posterior walls of the vagina, the type of mesh used, the type of sutures used, the tension of the implanted mesh and reperitonealization of the mesh. CONCLUSIONS: There is a high practice variation in LSH and LSC performed by a selected group of Dutch gynecologists. Different methods have been described in the literature and there is no consensus on how to perform these procedures. A well-designed prospective study or randomized controlled trial with regard to the specific parts of these procedures is needed to provide evidence for the best surgical technique. The outcomes of these studies will help to establish evidence-based guidelines.

Functional characteristics of vaginal fibroblastic cells from premenopausal women with pelvic organ prolapse.

Pelvic organ prolapse (POP) remains a great therapeutic challenge with no optimal treatment available. Tissue maintenance and remodelling are performed by fibroblasts, therefore altered cellular functionality may influence tissue quality. In this study, we evaluated functional characteristics of fibroblastic cells from tissues involved in POP. To rule out normal ageing tissue degeneration, biopsies from 18 premenopausal women were collected from the precervical region (non-POP site) after hysterectomy of 8 healthy and 10 POP cystocele cases (POP-Q stage ≥ II). Extra tissues from the prolapsed sites were taken in the POP cases to distinguish between intrinsic and acquired cellular defects. Twenty-eight primary fibroblastic cultures were studied in vitro. A contractility assay was used to test fibroblast-mediated collagen contraction. Cellular mechanoresponses on collagen-coated or uncoated substrates were evaluated by measuring matrix remodelling factors at protein or gene expression levels. No differences were found between fibroblasts from the controls and the non-POP site of the case group. Fibroblastic cells from the prolapsed site showed delayed fibroblast-mediated collagen contraction and lower production of matrix metalloproteinase-2 (MMP-2) on collagen-coated plates. On uncoated surfaces the gene MMP-2 and its tissue inhibitor of metalloproteinases-2 were up-regulated in POP site fibroblastic cells. In conclusion, fibroblastic cells derived from prolapsed tissues of patients with cystocele, display altered in vitro functional characteristics depending on the surface substrate and compared with non-prolapsed site. This implies an acquired rather than an intrinsic defect for most patients with cystocele, and should be taken into account when trying to improve treatments for POP.

Changes in tissue composition of the vaginal wall of premenopausal women with prolapse.

OBJECTIVE: The objective of this study was to compare histological and biochemical features of the (normal) precervical anterior vaginal wall and the prolapsed anterior vaginal wall of women with pelvic organ prolapse (POP). These data were compared to tissue of the precervical anterior vaginal wall of age-matched controls without POP to identify possible intrinsic and acquired effects. STUDY DESIGN: Biopsies were collected from the apex of the anterior vaginal cuff after hysterectomy from a control group of 13 premenopausal women undergoing hysterectomy for benign gynecological diseases, and a case group of 13 premenopausal women undergoing prolapse surgery (cystocele POP-Quantification stage ≥2). In women with POP an additional full-thickness vaginal wall sample was taken from the POP site during anterior colporrhaphy. Histomorphometric and biochemical analysis were performed for different components of the extracellular matrix. RESULTS: There were no differences between case and control group in the precervical vaginal wall tissue with respect to the different components of the extracellular matrix and the biochemical parameters. However, there was a tendency toward a higher amount of collagen III and elastin, and a significant increase of smooth muscle cells and pyridinoline collagen cross-links in the POP site compared to the non-POP site of the same POP patient. CONCLUSION: Our findings suggest that the changes seen in connective tissue in the anterior vaginal wall of women with POP are the effect, rather than the cause, of POP.

Fibroblasts from women with pelvic organ prolapse show differential mechanoresponses depending on surface substrates.

INTRODUCTION AND HYPOTHESIS: Little is known about dynamic cell-matrix interactions in the context of pathophysiology and treatments for pelvic organ prolapse (POP). This study sought to identify differences between fibroblasts from women with varying degrees of prolapse in reaction to mechanical stimuli and matrix substrates in vitro. METHODS: Fibroblasts from the vaginal wall of three patients with POP Quantification (POP-Q) system stages 0, II, and IV were stretched on artificial polymer substrates either coated or not coated with collagen I. Changes in morphology and anabolic/catabolic compounds that affect matrix remodelling were evaluated at protein- and gene-expression levels. Statistical analysis was performed using one-way analysis of variance (ANOVA), followed by Tukey-Kramer's post hoc test. RESULTS: POP fibroblasts show delayed cell alignment and lower responses to extracellular matrix remodelling factors at both enzymatic- and gene-expression levels compared with healthy fibroblasts. CONCLUSION: POP fibroblasts, when compared with healthy cells, show differential mechanoresponses on two artificial polymer substrates. This should be taken into account when designing or improving implants for treating POP.