Connective tissue in female urinary incontinence

An Overview of the Effect of Aging on the Female Urethra

Urethral function declines by roughly 15% per decade and profoundly contributes to the pathogenesis of urinary incontinence. Individuals with poor urethral function are more likely to fail surgical management for stress incontinence that focus on improving urethral support. The reduced number of intramuscular nerves and the morphologic changes in muscle and connective tissue collectively impact urethral function as women age. Imaging technologies like MRI and ultrasound have advanced our understanding of these changes. However, substantial knowledge gaps remain. Addressing these gaps can be crucial for developing better prevention and treatment strategies, ultimately enhancing the quality of life for aging women.

Vaginal reconstruction with a double-sided biomembrane-a preclinical experimental study on large animals

Tissue engineering techniques bring the promise of vaginal reconstruction with low invasiveness and fewer complications. However, existing biomaterial scaffolds remain limited in efficient vaginal recovery, focusing only on regenerating an epithelial layer, but muscle layers are missing or abnormal. The lack of a multi-tissue hierarchical structure in the reconstructed vagina leads to shrinking, stenosis, and fibrosis. Here, an acellular matrix named a double-sided biomembrane (DBM) is demonstrated for vaginal recovery. The regeneration of epithelial and muscle layers is achieved simultaneously since the smooth side of the DBM is helpful for guiding epithelial cell growth, while its loose and porous side guides muscle cell growth. In addition, the DBM demonstrates excellent mechanical properties similar to vaginal tissue, and hydrophilicity. Therefore, neovaginas were observed in the fourth and twelfth weeks after DBMs were transplanted to repair full-thickness vaginal defects (4 cm) that we established in large animals. The DBMs can effectively promote rapid epithelialization, the formation of large muscle bundles, higher rates of angiogenesis, and the restoration of physiological function in a neovagina. That is, the injured vagina achieves nearly complete recovery in anatomy and function, similar to a normal vagina. These preclinical results indicate that the DBM has prospects for vaginal injury repair.

The female urethra: urethral function throughout a woman's lifetime

INTRODUCTION AND HYPOTHESIS

The objective of this narrative review is to describe changes in urethral function that occur during a woman's lifetime. Evaluation of urethral function includes measurements of urethral closure pressure, at rest and during stress, leak point pressure, and the detailed study of anatomical and histological changes of the urethral sphincteric mechanism.

METHODS

A literature search in MEDLINE, PubMed, and relevant journals from 1960 until 2020 was performed for articles dealing with urethral function and the impact of aging, pregnancy, and childbirth, female hormones, and menopausal transition on the urethral sphincteric mechanism. Longitudinal and cross-sectional epidemiological surveys, studies on histological changes in urethral anatomy during aging, and urodynamic data obtained at different points in a woman's lifetime, during pregnancy, after childbirth, as well as the effects of female hormones on urethral sphincter function are reviewed. Relevant studies presenting objective data are analyzed and briefly summarized.

RESULTS AND CONCLUSIONS

The findings lead one to conclude that a constitutional or genetic predisposition, aging, and senescence are the most prominent etiological factors in the development of urinary incontinence and other pelvic floor disorders. Vaginal childbirth dilates and may damage the compressed pelvic supportive tissues and is invariably associated with a decline in urethral sphincter function. Pregnancy, hormonal alterations, menopausal transition, weight gain, and obesity are at best of secondary influence on the pathology of lower urinary tract dysfunction. The decline of circulating estrogens during menopausal transition may play a role in the transition of fibroblasts to cellular senescence.

Advances in the molecular pathogenesis and cell therapy of stress urinary incontinence

Stress urinary incontinence (SUI) is very common in women. It affects patients' mental and physical health, and imposed huge socioeconomic pressure. The therapeutic effect of conservative treatment is limited, and depends heavily on patient persistence and compliance. Surgical treatment often brings procedure-related adverse complications and higher costs for patients. Therefore, it is necessary to better understand the potential molecular mechanisms underlying stress urinary incontinence and develop new treatment methods. Although some progress has been made in the basic research in recent years, the specific molecular pathogenic mechanisms of SUI are still unclear. Here, we reviewed the published studies on the molecular mechanisms associated with nerves, urethral muscles, periurethral connective tissue and hormones in the pathogenesis of SUI. In addition, we provide an update on the recent progresses in research on the use of cell therapy for treating SUI, including research on stem cells therapy, exosome differentiation and gene regulation.

Improvement of Cell Growth of Uterosacral Ligament Fibroblast Derived from Pelvic Organ Prolapse Patients by Cold Atmospheric Plasma Treated Liquid

Pelvic organ prolapse (POP) is a chronic disorder that affects quality of life in women. Several POP treatments may be accompanied by abrasion, constant infection, and severe pain. Therefore, new treatment methods and improvements in current treatments for POP are required. Non-thermal atmospheric-pressure plasma is a rising biomedical therapy that generates a mixed cocktail of reactive species by different mechanisms. In this study, we applied a cylinder-type dielectric barrier discharge plasma device to create a plasma-treated liquid (PTL). The PTL was added to primary cultured human uterosacral ligament fibroblast (hUSLF) cells from POP patients at each stage. Surprisingly, treatment with diluted PTL increased hUSLF cell viability but decreased ovarian cancer cell viability. PTL also decreased cell apoptosis in hUSLF cells but increased it in SKOV3 cells. Our results suggest that PTL protects hUSLF cells from cell apoptosis by controlling the p53 pathway and improves cell viability, implying that PTL is a promising application for POP therapy.

Association between pelvic floor disorders and hernias

INTRODUCTION AND HYPOTHESIS

Connective tissue disorders may contribute to pelvic floor disorders (PFDs). Like PFDs, abdominal wall hernias are more common in patients with systemic connective tissue disorders. We conducted this study to explore the possible association between PFDs and hernias in adult women.

METHODS

We obtained the data for this study from a study of PFDs among parous women. At enrollment, stress urinary incontinence (SUI), overactive bladder (OAB), and anal incontinence (AI) were assessed using the Epidemiology of Prolapse and Incontinence Questionnaire (EPIQ) and pelvic organ prolapse (POP) was assessed through the Pelvic Organ Prolapse Quantification (POP-Q) examination. Participants were asked to report hernia surgery and list their hernia types. We compared the prevalence of PFDs in those with and without hernias using chi-square test. We used multiple regression analysis to adjust for obstetric and sociodemographic variables.

RESULTS

Among 1529 women, 79 (5.2%) reported history of hernia surgery. The prevalence of POP was 7.6% (6 cases) vs. 7.4% (107 cases), the prevalence of SUI was 7.6% (6 cases) vs. 9.9% (144 cases), the prevalence of OAB was 7.6% (6 cases) vs. 5.7% (83 cases), and the prevalence of AI was 7.6% (6 cases) vs. 10.8% (156 cases) in those with hernias compared to those without hernias, respectively. None of these differences were statistically significant. There was no association between hernias and PFDs after adjustment for type of delivery, number of deliveries, age group, primary racial background, weight category, and smoking status.

CONCLUSION

In this study, we could not find any association between hernias and PFDs.

Bladder ultrasonography for diagnosing detrusor overactivity: test accuracy study and economic evaluation

BACKGROUND

Urodynamics (UDS) has been considered the gold standard test for detrusor overactivity (DO) in women with an overactive bladder (OAB). Bladder ultrasonography to measure bladder wall thickness (BWT) is less invasive and has been proposed as an alternative test.

OBJECTIVES

To estimate the reliability, reproducibility, accuracy and acceptability of BWT in women with OAB, measured by ultrasonography, in the diagnosis of DO; to explore the role of UDS and its impact on treatment outcomes; and to conduct an economic evaluation of alternative care pathways.

DESIGN

A cross-sectional test accuracy study.

SETTING

22 UK hospitals.

PARTICIPANTS

687 women with OAB.

METHODS

BWT was measured using transvaginal ultrasonography, and DO was assessed using UDS, which was performed blind to ultrasonographic findings. Intraobserver and interobserver reproducibility were assessed by repeated measurements from scans in 37 and 57 women, respectively, and by repeated scans in 27 women. Sensitivity and specificity were computed at pre-specified thresholds. The smallest real differences detectable of BWT were estimated using one-way analysis of variance. The pain and acceptability of both tests were evaluated by a questionnaire. Patient symptoms were measured before testing and after 6 and 12 months using the International Consultation on Incontinence modular Questionnaire Overactive Bladder (short form) (ICIQ-OAB) questionnaire and a global impression of improvement elicited at 12 months. Interventions and patient outcomes were analysed according to urodynamic diagnoses and BWT measurements. A decision-analytic model compared the cost-effectiveness of care strategies using UDS, ultrasonography or clinical history, estimating the cost per woman successfully treated and the cost per quality-adjusted life-year (QALY).

RESULTS

BWT showed very low sensitivity and specificity at all pre-specified cut-off points, and there was no evidence of discrimination at any threshold (p = 0.25). Extensive sensitivity and subgroup analyses did not alter the interpretation of these findings. The smallest detectable difference in BWT was estimated to be 2 mm. Pain levels following both tests appeared relatively low. The proportion of women who found the test 'totally acceptable' was significantly higher with ultrasonography than UDS (81% vs. 56%; p < 0.001). Overall, subsequent treatment was highly associated with urodynamic diagnosis (p < 0.0001). There was no evidence that BWT had any relationship with the global impression of improvement responses at 20 months (p = 0.4). Bladder ultrasonography was more costly and less effective than the other strategies. The incremental cost-effectiveness ratio (ICER) of basing treatment on the primary clinical presentation compared with UDS was £491,500 per woman successfully treated and £60,200 per QALY. Performing a UDS in those women with a clinical history of mixed urinary incontinence had an ICER of £19,500 per woman successfully treated and £12,700 per QALY compared with the provision of urodynamic to all women. For DO cases detected, UDS was the most cost-effective strategy.

CONCLUSION

There was no evidence that BWT had any relationship with DO, regardless of the cut-off point, nor any relationship to symptoms as measured by the ICIQ-OAB. Bladder ultrasonography has no diagnostic or prognostic value as a test in this condition. Furthermore, despite its greater acceptability, BWT measurement was not sufficiently reliable or reproducible.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN46820623.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 7. See the NIHR Journals Library website for further project information.

Quantitative Sonographic Differences in Mid-Urethra between Postmenopausal Women with and without Stress Urinary Incontinence

AIM

The aim of this study was to evaluate midurethral tissue characteristics in continent and stress urinary incontinent postmenopausal women by using transvaginal ultrasound gray-level histogram.

METHODS

Thirty-seven patients with stress urinary incontinence (SUI) and 77 patients without SUI were evaluated. Vaginal ultrasound gray-level histograms were performed by 2 gynecologists blinded to patients' SUI statuses. The mean gray-level (MGL) of ultrasound gray-level histogram, representing the echogenicity of a region of interest, was measured in the anterior and posterior midurethral wall along a vertical ultrasound beam. The difference in MGL between anterior and posterior (AP difference) midurethra was calculated.

RESULTS

The MGL value of SUI patients was found to be lower in posterior (p = 0.008) and higher in anterior midurethral region (p = 0.001) when compared with control group. In addition, the difference in MGL between anterior and posterior midurethra (AP difference) was found to be higher in SUI group (p < 0.001). Multivariate analysis by logistic regression including confounding factors revealed that AP difference was independently associated with presence of SUI (adjusted OR 1.14, 95% CI 1.08-1.20, p < 0.001). Intra- and inter-observer reproducibility was found to be high with intraclass correlation coefficient of 0.83 and 0.78, respectively.

CONCLUSION

Postmenopausal SUI patients might have a distinct midurethral echogenicity pattern with the quantitative ultrasonography.

Expression of matrix metalloproteinase-1 in round ligament and uterosacral ligament tissue from women with pelvic organ prolapse

To evaluate the matrix metalloproteinase-1 (MMP-1) expression in different parts of pelvic connective tissue in postmenopausal women with and without pelvic organ prolapse (POP). Ninety-one samples were obtained from only postmenopausal women (42 with POP and 49 non-POP subjects). All women were evaluated by pelvic organ prolapse quantitation. The POP group had stage 2 or more, and the controls had stage 1 or less. Round ligament (RL) and uterosacral ligament (USL) biopsies were obtained from women with POP and controls. Immunohistochemistry for MMP-1 was performed on formalin-fixed and paraffin-embedded sections. The two groups were matched for age, body mass index, parity and postmenopausal status. MedCalc Statistical Software Programme Version 12.0.5 was used for statistical analysis. Expression of MMP-1 were significantly higher in both RL and USL tissue from postmenopausal women with POP, compared with controls. MMP-1 immunoreactivities were identified in both RL and USL biopsies from all women with and without POP. The expression pattern of MMP-1 were similar in these ligaments and were significantly higher in POP group compared with control subjects. These changes indicate a possible relation between MMP-1 expression of RL and USL in women with and without POP.

Decreased expression of elastin, fibulin-5 and lysyl oxidase-like 1 in the uterosacral ligaments of postmenopausal women with pelvic organ prolapse

AIM

Pelvic organ prolapse is associated with defects in connective tissues, including elastic fibers. The purpose of this study was to investigate the expression of fibulin-5 and lysyl oxidase-like 1 (LOXL1), which play an essential role in the synthesis and assembly of elastic fibers, in the uterosacral ligaments of women with advanced pelvic organ prolapse (POP) compared with controls.

METHOD

Specimens were obtained prospectively during transvaginal or abdominal hysterectomy from 30 women with advanced pelvic organ prolapse and 30 controls matched to the POP group for age and parity among postmenopausal women with benign gynecologic diseases. The expressions of elastin, fibulin-5 and LOXL1 in uterosacral ligaments were measured by immunohistochemistry.

RESULTS

We detected a decreased, sometimes absent, expression of fibulin-5 and LOXL1 in the uterosacral ligaments of women with POP, despite a positive expression of elastin. There was a decrease in positive percentage of LOXL1 in the POP group (23.3%) compared with the controls (60%) (P = 0.004). With immunolabeling intensity classified as negative, weak, moderate or strong, there was a decrease in the expression of fibulin-5 in the POP group (P = 0.049). We also detected a significantly decreased expression of LOXL1 in the POP group (P = 0.001).

CONCLUSIONS

There was decreased expression of fibulin-5 and LOXL1 in the uterosacral ligaments of patients with pelvic organ prolapse, while the elastin expression was equivalent, which may suggest the possibility of defects in elastic fiber remodeling in the postpartum period and contribute to POP.

The integral system

The Integral System is a total care management system based on the Integral Theory which states 'prolapse and symptoms of urinary stress, urge, abnormal bowel & bladder emptying, and some forms of pelvic pain, mainly arise, for different reasons, from laxity in the vagina or its supporting ligaments, a result of altered connective tissue'.

NORMAL FUNCTION

The organs are suspended by ligaments against which muscles contract to open or close the their outlet tubes, urethra and anus. These ligaments fall naturally into a three-zone zone classification, anterior, middle, and posterior.

DYSFUNCTION

Damaged ligaments weaken the force of muscle contraction, causing prolapse and abnormal bladder and bowel symptoms.

DIAGNOSIS

A pictorial diagnostic algorithm relates specific symptoms to damaged ligaments in each zone.

TREATMENT

In mild cases, new pelvic floor muscle exercises based on a squatting principle strengthen the natural closure muscles and their ligamentous insertions, thereby improving the symptoms predicted by the Theory. With more severe cases, polypropylene tapes applied through "keyhole" incision using special instruments reinforce the damaged ligaments, restoring structure and function. Problems that can be potentially addressed by application of the Integral SystemUrinary stress incontinenceUrinary urge incontinenceAbnormal bladder emptyingFacal incontinence and "obstructed evacuation" ("constipation")Pelvic pain, and some types of vulvodynia and interstitial cystitisOrgan prolapse.

CONCLUSIONS

Organ prolapse and symptoms are related, and both are mainly caused by laxity in the four main suspensory ligaments and perineal body. Restoration of ligament/fascial length and tension is required to restore anatomy and function.

Transobturator vaginal tape inside out for treatment of urethral sphincter mechanism incompetence: preliminary results in 7 female dogs

OBJECTIVES

To evaluate the clinical efficacy of the transobturator vaginal tape inside-out (TVT-O) in incontinent female dogs affected with urethral sphincter mechanism incompetence (USMI) and to determine its urodynamic and morphologic effects.

STUDY DESIGN

Case series.

ANIMALS

Incontinent spayed female dogs (n=7).

METHODS

TVT-O tape was inserted in 7 incontinent female dogs diagnosed with USMI. Urethral pressure profilometry (UPP) and vaginourethrograms were performed preoperatively, and 1 and 3 months postoperatively. Clinical efficacy of the technique was evaluated and complications reported. Follow-up information was evaluated by a telephone questionnaire.

RESULTS

All dogs were continent immediately after the procedure. Incontinence recurred 2 months after surgery in 1 dog and was treated by phenylpropanolamine administration. At mean follow-up time of 11.3 months, 6 of 7 dogs were continent. An iatrogenic urethral tear occurred intraoperatively in 1 dog. No postoperative complications were encountered. The postoperative UPPs showed significantly increased maximal urethral closure pressure and integrated pressure. Postoperative vaginourethrograms were unremarkable. The surgical procedure did not modify the location of the urinary bladder neck in dogs with a "pelvic urinary bladder" preoperatively.

CONCLUSIONS

TVT-O was efficient in maintaining short term continence in 6 of 7 dogs affected with USMI.

Evaluation of the ratio of collagen type III to collagen type I in periurethral tissues of sexually intact and neutered female dogs

OBJECTIVE

To determine the ratio of collagen type III to collagen type I in the periurethral tissues of sexually intact and neutered female dogs.

ANIMALS

8 neutered and 34 sexually intact female dogs.

PROCEDURES

Tissues were obtained from female dogs euthanized for non-urinary tract-related reasons. Indirect immunofluorescent antibody detection of type I and collagen type III was performed by use of confocal microscopy on 2 periurethral samples from each dog, and the ratios of collagen type III to type I area fraction and total area were determined.

RESULTS

No significant differences were detected in the collagen ratios of periurethral tissues between sexually intact and neutered female dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

In contrast to differences in periurethral collagen content found between pre- and postmenopausal women, such differences may not occur in dogs. This implies that changes in pelvic organ support structures may not play an important role in urinary incontinence in neutered female dogs. Further evaluation is needed to determine the role of age on collagen and pelvic organ support structures in the pathogenesis of canine urinary incontinence.

Changes in expression of fibulin-5 and lysyl oxidase-like 1 associated with pelvic organ prolapse

OBJECTIVES

Pelvic organ prolapse is associated with defects in connective tissue including elastic fibers. The purpose of this study was to investigate expression of fibulin-5 and lysyl oxidase-like 1, which play an essential role in synthesis and assembly of elastic fibers in the uterosacral ligament, in samples taken from women with advanced pelvic organ prolapse compared with controls.

STUDY DESIGN

Specimens were obtained prospectively during abdominal hysterectomy from 30 women with advanced pelvic organ prolapse and 30 controls matched to the study group for age and parity among postmenopausal women with benign gynecologic pathology. Expression levels of protein and mRNA of fibulin-5 and lysyl oxidase-like 1 in uterosacral ligaments were measured by Western blot analysis and real-time quantitative polymerase chain reactions. For statistical analyses, Student's t-test, chi-square test, Mann-Whitney U test, Fisher's exact test and Spearman's correlation were used.

RESULTS

Significant decrease in the expression of mRNA of fibulin-5 was found in patients with prolapse (P-value=0.042; 0.743+/-0.229 and 1.061+/-0.537). The expression of mRNA of lysyl oxidase-like 1 was increased in the patient group (P-value=0.017; 4.099+/-2.832 and 1.816+/-1.602). Similar results were shown in Western blot analysis. Differences in expression of fibulin-5 and lysyl oxidase-like 1 were noted according to stage of prolapse (P-value=0.037 and 0.009).

CONCLUSIONS

There was decreased expression of fibulin-5 and increased expression of lysyl oxidase-like 1 in uterosacral ligaments in patients with pelvic organ prolapse, which suggests the possibility of defects in elastin synthesis.

Does COLIA1 SP1-binding site polymorphism predispose women to pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS

COLIA1 polymorphism is associated with increased risk for stress urinary incontinence. We hypothesize that a similar association exists with pelvic organ prolapse (POP).

METHODS

Patients with advanced prolapse and healthy controls were evaluated by interview, validated questionnaires, and pelvic examination. DNA was extracted from peripheral blood, and polymerase chain reaction was performed to determine the presence or absence of the polymorphism. Power calculation indicated the need for 36 patients in each arm.

RESULTS

The prevalence of the polymorphic heterozygous genotype (GT) in the study and control groups was 33.3% and 19.4%, respectively, leading to an odds ratio of 1.75. This difference, however, did not reach statistical significance (p = 0.27).

CONCLUSIONS

The COLIA1 polymorphism was not significantly associated with increased risk for POP.

Tissue mechanics, animal models, and pelvic organ prolapse: a review

Pelvic floor disorders such as pelvic organ prolapse, urinary incontinence, and fecal incontinence affect a large number of women each year. The pelvic floor can be thought of as a biomechanical structure due to the complex interaction between the vagina and its supportive structures that are designed to withstand the downward descent of the pelvic organs in response to increases in abdominal pressure. Although previous work has highlighted the biochemical changes that are associated with specific risk factors (i.e. parity, menopause, and genetics), little work has been done to understand the biomechanical changes that occur within the vagina and its supportive structures to prevent the onset of these pelvic floor disorders. Human studies are often limited due to the challenges of obtaining large tissue samples and ethical concerns. Therefore, it is necessary to investigate the use of animal models and their importance in understanding how different risk factors affect the biomechanical properties of the vagina and its supportive structures. In this review paper, we will discuss the different animal models that have been previously used to characterize the biomechanical properties of the vagina: including non-human primates, rodents, rabbits, and sheep. The anatomy and preliminary biomechanical findings are discussed along with the importance of considering experimental conditions, tissue anisotropy, and viscoelasticity when characterizing the biomechanical properties of vaginal tissue. Although there is not a lot of biomechanics research related to the vagina and pelvic floor, the future is exciting due to the significant potential for scientific findings that will improve our understanding of these conditions and hopefully lead to improvements in the prevention and treatment of pelvic disorders.

Comparison of Human to Macaque Uterosacral–Cardinal Ligament Complex and Its Relationship to Pelvic Organ Prolapse

The uterosacral–cardinal ligament complex is thought to be the critical structure responsible for uterine and apical vaginal support. It is ill defined and can be difficult to dissect in the cadaver lab and in the operating room. Even less information is available on the analogous structures in the monkey model. We present this report to bring together what little is known to aid in studying this model and pelvic organ prolapse (POP), and to point out the need for critical assessment of this hormone-responsive tissue in the process of drug development.

Competing Interests: This article was sponsored by Covance Inc. and Schering-Plough. The authors did not declare any other competing interests.

Differential elastin and tenascin immunolabeling in the uterosacral ligaments in postmenopausal women with and without pelvic organ prolapse

Connective tissue, consisting mainly of collagen and structural glycoproteins, is an important part of the supportive structures of the genitourinary region. Relatively few data have been published with respect to the role of elastin and glycoproteins in pelvic organ prolapse (POP). Connective tissue of the uterosacral ligament in postmenopausal women with and without genital prolapse was compared. Fifty-nine consecutive women referred for hysterectomy were included in the study. The patients had POP or benign gynecological disease (e.g. myoma of the uterus). Tissue samples from the uterosacral ligament were investigated for localization and distribution of tenascin and elastin using immunofluorescence microscopy. Tissue samples of women with prolapse showed a significantly (p<0.001) weaker immunofluorescent labeling of tenascin compared to samples taken from women without prolapse. Tenascin was detectable in tissues of all women with POP, whereas its immunolabeling was decreased in the uterosacral ligament in women without POP. Intact elastin fibers were observed in tissues of all women without POP, whereas elastin was undetectable or sometimes fragmented in the uterosacral ligament in women with POP. Greater amounts of tenascin and lesser amounts of elastin were therefore found in patients with POP. These results suggest that an altered turnover of connective tissue in the uterosacral ligament might be responsible for the presence of pelvic floor relaxation in postmenopausal women. These data indicate a complex architecture of the extracellular matrix in the uterosacral ligaments, with marked differences in tenascin and elastin expression between postmenopausal women with or without POP.

Differences in mRNA and protein expression of small proteoglycans in vaginal wall tissue from women with and without stress urinary incontinence

BACKGROUND

To investigate changes in mRNA and protein levels of biglycan (BGN), decorin (DCN) and fibromodulin (FMOD) in vaginal wall tissue from women with stress urinary incontinence (SUI) compared to menstrual-cycle matched continent women.

METHODS

We determined mRNA expressions of BGN, DCN and FMOD by quantitative real-time PCR. They were localized in vaginal wall tissue by immunohistochemistry. We performed western blot analysis to examine protein expression.

RESULTS

BGN, DCN and FMOD co-localized with collagen and elastin in the extracellular matrix (ECM) of vaginal wall tissue from both groups. The mRNA expression of FMOD was significantly lower in cases versus controls in the proliferative phase (P = 0.03). DCN mRNA expression in cases was higher in the proliferative (P = 0.05) and secretory phases (P = 0.02) versus controls. BGN mRNA expression showed no significant differences in either phase. Protein expression of FMOD in cases was lower in the proliferative phase versus controls (six out of nine pairs), whereas DCN and BGN protein expression in the secretory phase in cases was higher (seven out of nine pairs).

CONCLUSION

BGN, DCN and FMOD expressions in vaginal wall tissue differ in women with SUI and are hormonally modulated. Differences in small proteoglycans may contribute to the altered pelvic floor connective tissues found in these women.

Immunohistochemical analysis of collagen types I, III, IV and α-actin in the urethra of sexually intact and ovariectomized beagles

Urinary incontinence is a widespread problem in both postmenopausal women and ovariectomized dogs. The objective of this study was to investigate the influence of ovariectomy on the immunoreactivity and the distribution pattern of collagens I, III, IV and alpha-actin in the canine urethra. The immunohistochemical results were evaluated in five sexually intact and five ovariectomized beagles. The immunostaining of both collagens I and III delineated urethral connective tissue fibres and co-localized within in the fibres of both groups. The basement membranes of smooth muscle cells and sinusoids showed marked type IV collagen expression, whereas only faint immunoreactivity was present at the urothelial-stromal interface. No differences could be detected in the expression or distribution of the assessed collagen types and actin between ovariectomized and control animals. In conclusion, ovariectomy does not appear to have an effect on urethral collagens I, III, IV and smooth muscle actin in the dog, as ascertained by immunohistochemistry.

Failure of elastic fiber homeostasis leads to pelvic floor disorders

Pelvic floor disorders, a group of conditions affecting adult women, include pelvic organ prolapse and urinary incontinence. Vaginal childbirth and aging are risk factors, and weakening of the pelvic support structures is a major aspect of the pathology. However, the underlying molecular mechanism remains unknown. Female reproductive organs are rich in elastic fibers that turn over slowly in most adult tissues but undergo massive remodeling in the reproductive organs through pregnancy and birth. Here we show that a failure to maintain elastic fiber homeostasis in mice causes pelvic floor disorders. Lysyl oxidase-like-1 (LOXL1), a protein essential for the postnatal deposition of elastic fibers, was highly expressed and regulated in the reproductive tract of the mouse, and its expression was diminished during aging. LOXL1 deficiency caused an inability of reproductive tissues to replenish elastic fibers after parturition, leading to pelvic organ prolapse, weakening of the vaginal wall, paraurethral pathology, and lower urinary tract dysfunction. These data demonstrate the importance of elastic fibers for maintaining structural and functional integrity of the female pelvic floor. Our findings raise the possibility that a failure of elastic fiber homeostasis, either due to genetic predisposition or advancing age, could underlie the etiology of pelvic floor dysfunction in women.

Increased expression of matrix metalloproteinase 2 in uterosacral ligaments is associated with pelvic organ prolapse

The uterosacral ligaments are an important part of the pelvic support system and connective tissue alterations are thought to contribute to the development of pelvic organ prolapse (POP). The objective of this study was to compare the expression of matrix metalloproteinases (MMPs) 1 and 2 in these ligaments in women with and without POP. We analyzed the tissue samples obtained from left and/or right uterosacral ligaments of 17 women with POP and 18 controls by immunohistochemistry. There was no difference in MMP-1 expression between women with POP and those without. In contrast, the MMP-2 expression was significantly related to the presence of POP (p=0.004) rather than to age or parity. There was no difference in MMP-1 and MMP-2 expression between left and right uterosacral ligaments in women with POP compared to controls. Our findings strongly indicate that increased MMP-2 expression in uterosacral ligaments is associated with POP.

Rectocele Repair Using Biomaterial Augmentation: Current Documentation and Clinical Experience

Although the etiology of rectocele remains debated, surgical innovations are currently promoted to improve anatomic outcome while avoiding dyspareunia and alleviating rectal emptying difficulties following rectocele surgery. Use of biomaterials in rectocele repair has become widespread in a short time, but the clinical documentation of their effectiveness and complications is limited. Medline and the Cochrane database were searched electronically from 1964 to May 2005 using the Pubmed and Ovid search engines. All English language publications including any of the search terms "rectocele," "implant," "mesh," "biomaterial," "prolapse," "synthetical," "pelvic floor," "biological," and "compatibility" were reviewed. This review outlines the basic principles for use of biomaterials in pelvic reconstructive surgery and provides a condensation of peer-reviewed articles describing clinical use of biomaterials in rectocele surgery. Historical and new concepts in rectocele surgery are discussed. Factors of importance for human in vivo biomaterial compatibility are presented together with current knowledge from clinical studies. Potential risks and problems associated with the use of biomaterials in rectocele and pelvic reconstructive surgery in general are described. Although use of biomaterials in rectocele and other pelvic organ prolapse surgery offers exciting possibilities, it raises treatment costs and may be associated with unknown and potentially severe complications at short and long term. Clinical benefits are currently unknown and need to be proven in clinical studies.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

TARGET AUDIENCE

After completion of this article, the reader should be able to explain that the objective of surgical treatment is to improve anatomic outcome and alleviate rectal emptying difficulties, describe the efficacy of biomaterials in rectocele repair, and summarize the potential risks and problems associated with use of biomaterials in rectocele and pelvic reconstructive surgery.

Uterosacral ligament in postmenopausal women with or without pelvic organ prolapse

The uterosacral ligaments are thought to contribute to pelvic support. The objective of this study was to compare the structural components of these ligaments in women with and without pelvic organ prolapse (POP). We characterized uterosacral ligaments of 25 postmenopausal women with POP and 16 controls histomorphologically and immunohistochemically by quantifying their content of collagen I, III, and smooth muscle using a computerized image analysis. In 84% the uterosacral ligaments were composed of more than 20% of smooth muscle cells. There was no difference in collagen I expression and smooth muscle cell amount between women with POP and those without. In contrast, the collagen III expression was significantly related to the presence of POP (p<0.001) rather than age or parity. Our findings suggest that the higher collagen III expression might be a typical characteristic of POP patients' connective tissue. The considerable amount of smooth muscle cells in uterosacral ligaments may provide pelvic support.

Visualization of the endopelvic fascia by transrectal three-dimensional ultrasound

The aim of our pilot study was to explore the feasibility of visualizing the endopelvic fascia by transrectal three-dimensional (3D) ultrasound. Transrectal 3D ultrasound was performed in 12 nulliparous women and 11 women with a history of vaginal delivery. A 6-10 MHz volume probe was used to examine the suburethral anterior vaginal wall. In all women, an echogenic layer was identified at an average of 3-5 mm from the vaginal surface. This echogenic layer was found to be contiguous to the lateral pelvic sidewall and uninterrupted in 10 of 12 nulliparous women, whereas gaps in this layer were identified in all 11 parous women. We hypothesize that this echogenic layer may represent the suburethral component of the endopelvic fascia. Depending on the number and localization of the interruptions in this echogenic layer, the mechanical support of the pelvic floor seems to be weakened corresponding to a higher incidence of descensus of the anterior vaginal wall, which frequently was associated with urinary incontinence.

The prevalence of stress urinary incontinence among women operated on for abdominal wall hernias

The high co-occurrence of an abdominal wall hernia (AWH) and stress urinary incontinence (SUI) suggests that there is a common factor in the etiopathogenesis of these disorders in these patients.

Is stress urinary incontinence a familial condition?

BACKGROUND

Stress urinary incontinence (SUI) is a common problem of multifactorial origin. Some authors have claimed that it has a familial predisposition. This study was undertaken to investigate the prevalence of SUI among first-degree relatives of 154 women who had been operated on for this disorder and of 100 women without SUI.

METHODS

This report is concerned with a questionnaire-based, case-control study. A total of 154 women who had undergone operations for SUI and 100 women who denied having SUI were included. A comparison was made of 413 first-degree relatives of incontinent women and 372 first-degree relatives of continent women according to the demographic characteristics, obstetric and gynecologic history and risk factors for SUI. The prevalence of SUI was investigated among the relatives. Furthermore, the characteristics of the women who had SUI operation were compared according to the continence state of their families.

RESULTS

The prevalence of SUI was 71.4% among mothers and 24.6% among sisters of operated women compared with 40.3% among mothers and 11.6% among sisters of continent women (p < 0.05). Furthermore, the age at which symptoms began was significantly lower in the members of the 'incontinent families' (p < 0.001).

CONCLUSIONS

The relatives of incontinent women displayed a higher prevalence of SUI than the relatives of continent women. Although this condition has a multifactorial origin, the familial aggregation of SUI and the appearance of symptoms at younger ages in women with a family history of SUI suggest that heredity may play a significant role.

Basic science and translational research in female pelvic floor disorders: proceedings of an NIH-sponsored meeting

AIMS

To report the findings of a multidisciplinary group of scientists focusing on issues in basic science and translational research related to female pelvic floor disorders, and to produce recommendations for a research agenda for investigators studying female pelvic floor disorders.

METHODS

A National Institutes of Health (NIH)-sponsored meeting was held on November 14-15, 2002, bringing together scientists in diverse fields including obstetrics, gynecology, urogynecology, urology, gastroenterology, biomechanical engineering, neuroscience, endocrinology, and molecular biology. Recent and ongoing studies were presented and discussed, key gaps in knowledge were identified, and recommendations were made for research that would have the highest impact in making advances in the field of female pelvic floor disorders.

RESULTS

The meeting included presentations and discussion on the use of animal models to better understand physiology and pathophysiology; neuromuscular injury (such as at childbirth) as a possible pathogenetic factor and mechanisms for recovery of function after injury; the use of biomechanical concepts and imaging to better understand the relationship between structure and function; and molecular and biochemical mechanisms that may underlie the development of female pelvic floor disorders.

CONCLUSIONS

While the findings of current research will help elucidate the pathophysiologic pathways leading to the development of female pelvic floor disorders, much more research is needed for full understanding that will result in better care for patients through specific rather than empiric therapy, and lead to the potential for prevention on primary and secondary levels.

Diet as a risk factor for the development of stress urinary incontinence: a longitudinal study in women

OBJECTIVE

To assess the association between diet and the onset of stress urinary incontinence (SUI) in women aged 40 y plus.

DESIGN AND SETTING

The Leicestershire MRC Incontinence Study - a prospective longitudinal study of the prevalence, incidence and aetiology of urinary symptoms.

SUBJECTS AND METHODS

A total of 5816 women aged 40 y plus and living in the community. Urinary symptoms were reported in a postal questionnaire at baseline and at 1-y follow-up. Dietary intake was assessed in a food frequency questionnaire at baseline.

RESULTS

Intakes of total fat, saturated fatty acids and monounsaturated fatty acids were associated with an increased risk of SUI onset 1 y later. Of the micronutrients studied, zinc and vitamin B12 were positively associated with SUI onset.

CONCLUSION

The results from this prospective study suggest there may be an aetiological association between certain components of the diet and the onset of SUI. The findings need confirming and possible mechanisms to explain these associations need further investigation.

Tension-Free Vaginal Tape Efficacy in Relation to Collagen Quantity of Pubocervical Fascia

OBJECTIVE(S)

To investigate whether the quantity of collagen types I and III in the pubocervical fascia of women with genuine stress incontinence (GSI) affects the efficacy of the tension-free vaginal tape (TVT) procedure.

METHODS

Sixty-three patients participated in the study and were divided in 2 groups as follows: 37 patients with GSI and pelvic organ prolapse stage I (group 1), and 26 patients with pelvic organ prolapse stage I but not GSI (control group). Urodynamic studies confirmed the diagnosis of GSI. Biopsies were obtained during surgery from the pubocervical fascia.

RESULTS

The quantity of collagen types I and III was statistically significantly reduced in patients with GSI compared to the control group. The efficacy of the TVT procedure in patients with a significant reduction in collagen type I was an 82.1% cure. In patients with a significant reduction in collagen type III, the TVT efficacy was an 85.1% cure. The efficacy of the TVT procedure was not statistically significantly different between patients with GSI and a significant reduction in collagen types I and III, and patients with no reduction in collagen types I and III.

CONCLUSIONS

The significantly reduced quantity of collagen types I and III in the pubocervical fascia of women with GSI does not affect the efficacy of the TVT procedure at an average of 25 months of follow-up.

Collagen synthesis is not altered in women with stress urinary incontinence

AIMS

The objective of this study was to demonstrate that weakened pelvic floor support of the lower genitourinary tract in women with stress urinary incontinence (SUI) is due, in part, to decreased collagen synthesis and secretion and/or an altered ratio of collagen III/I synthesis by the fibroblasts of the endopelvic fascia and skin compared to that of women without evidence of pelvic floor weakening.

METHODS

Endopelvic fascia and skin biopsies were obtained from women with SUI (n = 14) and women without evidence of SUI or genital prolapse (n = 12). Fibroblast cultures established from the biopsies were incubated with 3H-proline in medium containing ascorbic acid for 3 hr. Conditioned medium was collected and cells were harvested. The radiolabeled collagens were precipitated and digested with collagenase. The collagen synthesized (as a percent of total protein) was determined. Collagen alpha1(III) was separated from collagen alpha1(I) and alpha2(I) by interrupted SDS-PAGE and the amount of (3)H-proline in each band was determined.

RESULTS

Collagen synthesis, expressed as percent of total protein synthesis, was not significantly different between fibroblasts obtained from women with or without SUI. The mean of collagen III/I synthesized in fibroblasts was not significantly different between fibroblasts obtained from women with or without SUI.

CONCLUSIONS

These data suggest that the lower collagen content in the endopelvic fascia and skin of women with SUI is not due to reduced collagen synthesis or selective reduction in synthesis of either collagen I or collagen III, compared to women without pelvic floor weakening.

Excretion of collagen derived peptides is increased in women with stress urinary incontinence

AIMS

The objective of this study was to demonstrate that weakened pelvic floor support of the lower genitourinary tract in women with stress urinary incontinence (SUI) is due to increased collagenolysis. When fibrillar collagen is degraded, pyridinium (PYD) crosslinks are released and excreted in the urine. Degradation of collagen also results in peptide fragments of various lengths which are excreted in the urine. Degradation of mature fibrillar collagen and collagen which has not been crosslinked can be assessed independently by measurement of both PYD and collagen-derived peptides in the urine.

METHODS

Twenty-four hour urine collections were obtained from women with SUI (n = 23) and women without urinary incontinence (n = 39). Urinary PYD concentration was assayed by ELISA. The urinary concentration of helical peptide alpha1 (I) 620-633 fragments derived from collagen was assayed by competitive enzyme immunoassay. Values were normalized to creatinine.

RESULTS

The mean urine PYD concentration for women with SUI (110.8 +/- 19.7 nM/mM creatinine) was not significantly different than that for women without SUI (85.2 +/- 13.7 nM/mM creatinine). The mean urine concentration of helical peptide alpha1 (I) 620-633 for women with SUI (0.80 +/- 0.13 microg/mg creatinine) was significantly (P < 0.02) higher than that for women without SUI (0.49 +/- 0.06 microg/mg creatinine).

CONCLUSIONS

These data suggest that collagenolytic activity in women with SUI is elevated compared to continent controls, as measured by urinary helical peptide alpha1 (I) 620-633 excretion. The lack of difference in urinary PYD excretion between the two populations suggests that the increased collagenolytic activity in women with SUI, compared to continent controls, is restricted to uncrosslinked collagen.

Periurethral connective tissue status of postmenopausal women with genital prolapse with and without stress incontinence

OBJECTIVE

Connective tissue consists mainly of collagen and structural glycoproteins and is considered an important factor of the supportive structures of the genitourinary region. Few data have been published as yet with respect to the role of connective tissue in pelvic floor relaxation and genuine stress incontinence (GSI). We compared periurethral connective tissue structures between continent and incontinent postmenopausal women with genital prolapse.

METHODS

Twenty-nine women underwent pelvic floor reconstructive surgery (anterior colporrhaphy: n = 29, sacrospinous fixation: n = 12), with biopsies obtained from the periurethral region. Fifteen patients and 14 women were incontinent and continent, respectively. Tissue samples were investigated for localization and distribution of collagen (types I, III, IV, V, VI) and glycoproteins (fibronectin, laminin, vitronectin) using immunofluorescent microscopic techniques.

RESULTS

Collagen types I, III, IV, V, and VI were found in all tissue samples. Compared with the continent women, the tissue samples of the incontinent women showed a significantly weaker immunohistochemical staining of type I, III, and VI collagen. No difference in staining patterns of collagen type IV and V, fibronectin, and laminin was observed between the two groups. Intact vitronectin was found in the periurethral tissues of all the continent women, whereas this glycoprotein was either absent or fragmented in the incontinent women.

CONCLUSIONS

Our results indicate an altered metabolism of connective tissue in the periurethral region with a significant decrease of collagen and vitronectin expression in postmenopausal women with pelvic floor relaxation with and without GSI.

Is diminished pubocervical fascia collagen content a risk factor for failure of surgical management of genuine stress urinary incontinence in women?

OBJECTIVE

The assessment of relationship between pubocervical collagen content and clinical results of surgical treatment of genuine stress urinary incontinence (GSUI) in women.

METHODS

Twenty-four women treated for genuine stress urinary incontinence were included into the study. All women underwent the same surgical procedure. The samples of pubocervical fascia were taken at the time of surgery. The contents of acid soluble, pepsin soluble, insoluble fraction of collagen, total collagen and collagen crosslinks were measured. The study of pubocervical fascia collagen metabolism included also estimation of collagenase activity. At follow-up done 5 years following surgery, 20 patients reported symptoms of GSUI (study group). Four women were still without symptoms of urine leakage (control group).

RESULTS

The biochemical parameters of pubocervical fascia did not show, statistically significant differences between compared groups.

CONCLUSION

The pubocervical fascia collagen metabolism does not have impact on the results of anti-incontinence surgery.