The use of synthetic sub-urethral slings in the treatment of female stress urinary incontinence

Management of vaginal mesh exposure: A systematic review

Objectives: To identify various predisposing factors, the clinical presentation, and the management of vaginal mesh-related complications, with special emphasis on mesh exposure and the indications for and results of vaginal mesh removal.

Methods: A systematic literature review was performed using a search strategy based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses criteria. PubMed was queried for studies regarding aetiology, risk factors, and management of vaginal mesh exposure from 1 January 2008 to June 2018. Full-text articles were obtained for eligible abstracts. Relevant articles were included, and the cited references were used to identify relevant articles not previously included.

Results: A total of 102 abstracts were identified from the PubMed search criteria. An additional 45 studies were identified based on review of the cited references. After applying eligibility criteria and excluding impertinent articles, 58 studies were included in the final analysis.

Conclusion: Numerous studies have found at least some degree of symptomatic improvement regardless of the amount of mesh removed. Focal areas of exposure or pain can be successfully managed with partial mesh removal with low rates of complications. With partial mesh removal, many patients will ultimately require subsequent mesh removal procedures. For this reason, complete mesh excision is an alternative for patients with diffuse vaginal pain, large mesh exposure, and extrusion of mesh into adjacent viscera. However, when considering complete mesh removal, it is important to counsel patients regarding possible complications of removal and the increased risk of recurrent stress urinary incontinence and pelvic organ prolapse postoperatively.

Abbreviations: MUS: midurethral sling; OR: odds ratio; POP: pelvic organ prolapse; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-analyses; SUI: stress urinary incontinence; TOT: transobturator; TVT: tension-free vaginal tape

Update on complications of synthetic suburethral slings

Synthetic suburethral slings have become the most widely used technique for the surgical treatment of stress urinary incontinence. Despite its high success rates, significant complications have been reported including bleeding, urethral or bladder injury, urethral or bladder mesh erosion, intestinal perforation, vaginal extrusion of mesh, urinary tract infection, pain, urinary urgency and bladder outlet obstruction. Recent warnings from important regulatory agencies worldwide concerning safety issues of the use of mesh for urogynecological reconstruction have had a strong impact on patients as well as surgeons and manufacturers. In this paper, we reviewed the literature regarding surgical morbidity associated with synthetic suburethral slings.

Urethral dysfunction in female mice with estrogen receptor β deficiency

Estrogen has various regulatory functions in the growth, development, and differentiation of the female urogenital system. This study investigated the roles of ERβ in stress urinary incontinence (SUI). Wild-type (ERβ^+/+) and knockout (ERβ^−/−) female mice were generated (aged 6–8 weeks, n = 6) and urethral function and protein expression were measured. Leak point pressures (LPP) and maximum urethral closure pressure (MUCP) were assessed in mice under urethane anesthesia. After the measurements, the urethras were removed for proteomic analysis using label-free quantitative proteomics by nano-liquid chromatography–mass spectrometry (LC-MS/MS) analysis. The interaction between these proteins was further analysed using MetaCore. Lastly, Western blot was used to confirm the candidate proteins. Compared with the ERβ^+/+ group, the LPP and MUCP values of the ERβ^−/− group were significantly decreased. Additionally, we identified 85 differentially expressed proteins in the urethra of ERβ^−/− female mice; 57 proteins were up-regulated and 28 were down-regulated. The majority of the ERβ knockout-modified proteins were involved in cell-matrix adhesion, metabolism, immune response, signal transduction, nuclear receptor translational regelation, and muscle contraction and development. Western blot confirmed the up-regulation of myosin and collagen in urethra. By contrast, elastin was down-regulated in the ERβ^−/− mice. This study is the first study to estimate protein expression changes in urethras from ERβ^−/− female mice. These changes could be related to the molecular mechanism of ERβ in SUI.

Synergistic effect of vaginal trauma and ovariectomy in a murine model of stress urinary incontinence: upregulation of urethral nitric oxide synthases and estrogen receptors

The molecular mechanisms underlying stress urinary incontinence (SUI) are unclear. We aimed to evaluate the molecular alterations in mice urethras following vaginal trauma and ovariectomy (OVX). Twenty-four virgin female mice were equally distributed into four groups: noninstrumented control; vaginal distension (VD) group; OVX group; and VD + OVX group. Changes in leak point pressures (LPPs), genital tract morphology, body weight gain, plasma 17β-estradiol level and expressions of neuronal nitric oxide synthase (nNOS), induced nitric oxide synthase (iNOS), and estrogen receptors (ERs—ERα and ERβ) were analyzed. Three weeks after VD, the four groups differed significantly in genital size and body weight gain. Compared with the control group, the plasma estradiol levels were significantly decreased in the OVX and VD + OVX groups, and LPPs were significantly decreased in all three groups. nNOS, iNOS, and ERα expressions in the urethra were significantly increased in the VD and VD + OVX groups, whereas ERβ expression was significantly increased only in the VD + OVX group. These results show that SUI following vaginal trauma and OVX involves urethral upregulations of nNOS, iNOS, and ERs, suggesting that NO- and ER-mediated signaling might play a role in the synergistic effect of birth trauma and OVX-related SUI pathogenesis.

Minimally invasive treatment for female stress urinary incontinence (SUI): a review including TVT, TOT, and mini-sling

Treatment for female stress urinary incontinence (SUI) has progressed rapidly over the past ten years in the search for less invasive methods to treat this disease. There have been over 100 procedures described in the literature to date to treat female SUI; however, only two procedures have stood the test of time and have adequate cure rates: the retropubic colposuspension (Burch, MMK) and the sling. The laparoscopic approach to minimize the Burch procedure was described in the 1990s, but the evolution of the retropubic tension-free vaginal tape sling (TVT) in the late 1990s revolutionized the treatment of female SUI. More recently, the transobturator technique (TOT) and the single-incision mini-sling have been reported in attempts to further reduce the risks of sling placement. The current chapter reviews the history of treatment of female SUI and the development of these newer, less-invasive techniques. The procedures themselves are described, the risks of mesh complications reviewed, and the literature reviewed for current data on the different approaches and procedures.

Stress urinary incontinence following vaginal trauma involves remodeling of urethral connective tissue in female mice

OBJECTIVE

The molecular mechanisms underlying stress urinary incontinence (SUI) are not clear. This study was conducted to evaluate molecular alterations in the urethras of mice with experimentally induced SUI.

STUDY DESIGN

Eighteen virgin female mice were equally distributed into three groups as follows: two groups undergoing vaginal distension (VD) for 1 h with 3 mm and 8 mm dilators each, and a non-instrumented control group. Changes in leak point pressure (LPP), morphology, lysyl oxidase (LOX) expression and the metabolism of urethral connective tissue were assessed.

RESULTS

The LPP was significantly decreased in the 3 mm and 8 mm VD groups compared with that in the control group. Collagen and elastin expression in the urethra was significantly decreased in the 8 mm VD group compared with that in the control group, while LOX expression was significantly enhanced.

CONCLUSIONS

SUI following vaginal trauma involves over-expression of LOX and decreased synthesis of extracellular matrix components or increased proteolysis in the urethra.

Production and in vitro evaluation of soy protein-based biofilms as a support for human keratinocyte and fibroblast culture

This study presents results on soy protein isolate (SPI) biofilm production and the corresponding effect on the stability and toxicity of the derived films. SPI biofilms were prepared from SPI chemically treated with formaldehyde at various concentrations (0%, 1%, 2%, and 3%) as cross-linking agents. In vitro SPI biofilm degradation was evaluated as a function of water absorption leading to weight and size modifications. SPI biofilm toxicity was determined as a function of human keratinocyte and fibroblast adhesion, viability, and proliferation. Cytokine gene expression supported this using reverse transcriptase polymerase chain reaction techniques. Our results confirm that SPI can be used to produce biofilms. The resulting SPI biofilms without formaldehyde swell significantly, which leads to their physical instability. Formaldehyde treatment enhanced the mechanical properties of these biofilms by covalently cross-linking polypeptide chains. The decreased water absorption was dependent on the amount of formaldehyde present. SPI biofilms with 2% and 3% formaldehyde were highly stable and easier to manipulate than those with 0% and 1% formaldehyde. Tissue culture analyses revealed that the SPI biofilms without formaldehyde were non-toxic to human cells (keratinocytes and fibroblasts). The presence of formaldehyde in biofilms did not have any effects on cell viability, adhesion, or proliferation. This was supported by the high level of messenger RNA expression of interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha by the keratinocytes and of IL-6 and IL-8 by the fibroblasts. Overall, we produced a stable, non-toxic soy protein support, which may be of potential interest in medical applications such as cell culture matrices and damaged tissue replacement.

Foreign body reaction in vaginally eroded and noneroded polypropylene suburethral slings in the female: a case series

INTRODUCTION AND HYPOTHESIS

Aim of this study was to investigate the pattern of the foreign body reaction of macroporous polypropylene mesh (MPPM) used in females for the treatment of stress urinary incontinence and to compare this pattern between eroded and noneroded tapes.

METHODS

Ten explanted suburethral slings, five eroded and five noneroded, were examined immunohistochemically under light microscopy; the tissue reaction was compared between eroded and noneroded materials.

RESULTS

Eroded material showed a significantly higher accumulation of macrophages around the filaments of the mesh.

CONCLUSIONS

This is the first study comparing reaction around eroded and noneroded MPPMs and indicates a more intense tissue reaction around eroded mesh, when compared to noneroded material. More studies are needed to prove whether the detected foreign body reaction was the actual trigger for the erosion.

Molecular mechanisms related to parturition-induced stress urinary incontinence

BACKGROUND

The molecular mechanisms underlying stress urinary incontinence (SUI) at the tissue level are poorly understood.

OBJECTIVE

To study genetic and molecular alterations in the urethras of animals with experimentally induced SUI.

DESIGN, SETTING, AND PARTICIPANTS

Cohort analysis of primiparous 2-month-old female Sprague-Dawley rats with experimentally induced SUI versus those who did not develop SUI in a university research laboratory setting.

INTERVENTION

Rats underwent intravaginal balloon dilation within 24 hours of parturition followed by bilateral ovariectomy one week later. Transvesical cystometry was performed 12 weeks after parturition. Rats were classified as continent (C) or incontinent (I) according to the results of cystometry.

MEASUREMENTS

The expression of over 22,000 genes in urethral tissue from the two groups was assessed with the use of an oligo microarray. The expression of relevant genes was confirmed by real-time polymerase chain reaction. Protein expression of small mothers against decapentaplegic 2 (Smad2), one of the differentially expressed genes, was extensively studied by immunohistochemistry and Western blot analysis. Regulation of Smad2 activity by transforming growth factor-beta (TGF-beta) was assessed in cultured urethral smooth muscle cells (USMCs).

RESULTS AND LIMITATIONS

After intervention, 14 (58.3%) rats remained continent and 10 (41.7%) became incontinent. There were significant differences in the expression of 42 urethral genes between continent and incontinent rats. The expression of genes involved in the TGF cellular signaling pathway (Smad2), collagen breakdown (matrix metalloproteinase 13 [Mmp13]), and smooth muscle inhibition (regulator of G-protein signaling 2 [Rgs2]) was significantly increased in the incontinent group. SMAD2 protein expression was significantly upregulated in the incontinent rats. In cultured USMCs, SMAD2 phosphorylation and nuclear translocation increased after Tgf-beta treatment.

CONCLUSIONS

Genes important in inflammation, collagen breakdown, and smooth muscle inhibition are upregulated in the urethras of female rats with parturition-associated incontinence.

Long-term follow-up of intravaginal slingplasty operation for urinary stress incontinence

The objective of this study was to evaluate the long-term complications of the intravaginal slingplasty (IVS) operation for stress urinary incontinence in women operated 5 years ago. Out of 25 operated patients, seven patients experienced erosion up to 5 years after the primary operations. In six patients, parts of the tape had to be removed several times. Two patients developed a suprapubic abscess. We recommend that the IVS tape is abandoned.

A comprehensive review of suburethral sling procedure complications

The study objective was to review the existing literature regarding complications of anti-incontinence sling procedures. PubMed listings using keywords related to slings and associated complications with no date or language restrictions through May 2007 and the Manufacturer and User Facility Device Experience Database were searched for specific device- and procedure-related complications. Where no information was available, published abstracts were cited. Published reports of complications for all types of anti-incontinence sling procedures are analyzed and reported. Sling-related complications are multiple but can be summarized from studies on 13737 cumulative patients as involving: voiding dysfunction (8 studies, 881 patients, 16.3% average overall incidence [OI]); detrusor overactivity (20 studies, 1950 patients, 15.4% OI); urinary retention (14 studies, 943 patients, 14.2% OI); erosion/extrusion (19 studies, 2197 patients, 6.03% OI); impact on quality of life-dyspareunia (2 studies, 175 patients, 4.3% OI); infections-most often urinary tract infections but severe infections such as abscess are reported (19 studies, 1487 patients, 5.5% OI); hematoma-most often pelvic or vaginal (4 studies, 3691 patients, 2% OI); pain (6 studies, 597 patients, 7.3% OI); abdominal and pelvic organ injury-bladder, urethra, vagina, and intestines (10 studies, 1816 patients, 3.3% OI); systemic complications-deep vein thrombosis, sepsis (case reports); and death (case reports). Cure rates for all slings are as follows: subjective (16 studies, 1541 patients, 95% OI, range 63%-99%), objective (15 studies, 1203 patients, 82% OI, range 51%-97%), and failure (8 studies, 599 patients, 11.5% OI, range 4%-37%). It is likely that sling-related complications are under-reported in the published medical literature and in the Manufacturer and User Facility Device Experience Database. This review reports on the incidence of known complications for all types of slings. Some complications are common to all sling techniques; however, with development of minimally invasive slings, device-related complications are reported and compared.

Urethral erosion after suburethral synthetic slings: risk factors, diagnosis, and functional outcome after surgical management

Urethral erosion (UE) is an uncommon but potentially severe complication after suburethral synthetic slings. We aimed to identify the risk factors and diagnostic modalities of UE and also functional outcome after UE surgical management. We retrospectively analyzed eight cases of UE managed in our department between 1997 and 2007. The main presumptive risk factors of UE were excessive sling tensioning (six of eight) and postoperative urethral dilation (four of eight). The most frequent symptoms included voiding difficulties (five of eight), storage symptoms (three of eight), pain (three of eight), and recurrent stress incontinence (three of eight). UE diagnosis was accessible to introital ultrasound (five of five) and confirmed by urethroscopy (eight of eight). Surgical management was performed in seven cases and included transvaginal sling removal with urethral repair (two of seven), endoscopic transurethral sling resection (four of seven), and combined approach (one of seven). All the approaches provided good functional outcomes. Transurethral endoscopy is a mini-invasive treatment of UE and should be tried first in selected cases.

Mechanical properties of polypropylene mesh used in pelvic floor repair

The aim of this study was the comparison of the stiffness of different meshes under two types of mechanical tests. Five different mesh types were mechanically tested. The methods used consisted on uniaxial tension test (tensile stiffness) and tape ring tests, experimental continuous compression of the mesh loops (flexural stiffness). The most significant difference of tensile stiffness behaviour appears between Aris and TVTO. From the analysis of the experimental data, we divided the flexural stiffness, in two main groups. The first group includes Auto Suture and Aris meshes. The two meshes seem to have a similar flexural behaviour. The second group includes TVTO, Uretex and Avaulta. The difference between these two groups is clearly evident comparing TVTO and Aris. This study shows that there are significant differences on the mechanical properties between urogynecology meshes.