Ultrasound appearances after mesh implantation--evidence of mesh contraction or folding?

Profiling of the macrophage response to polypropylene mesh burden in vivo

Pelvic organ prolapse (POP) surgical repair with polypropylene mesh (PPM) offers improved anatomical outcomes compared to reconstruction using native tissue. However, PPM repair is hampered by complications, most commonly pain or mesh exposure, occurring in over 10 % of cases. This maladaptive response is, in part, attributed to the host response to a foreign material. Previous studies have demonstrated that mesh properties, such as weight, pore size, and porosity, influence downstream outcomes. In addition, computational models and in vivo mechanistic studies demonstrate that mesh deforms after tensioning in prolapse surgery resulting in collapsed pores and wrinkles. To further investigate the role of pore collapse in mesh complications, PPM was implanted flat, or in configurations that would deform upon tensioning in a POP repair surgery using a non-human primate model. After twelve weeks, we analyzed mesh-tissue complexes to characterize the overall host response, profile the macrophage response, and observe the influence of macrophages in downstream healing outcomes that may lead to complications. The results confirm that mesh deformations reproduce mesh exposure and thinning of vagina. In the PPM configurations with the greatest deformation, mesh burden was the highest, which resulted in an overall decrease in the number of cells within the implantation site. Among the cells that were present, we observed a predominance of M1 pro-inflammatory macrophages. While flat mesh was associated with an organized cellular response, deformed mesh led to an increasingly disorganized response as mesh burden increased. Nearly half of the responding macrophages expressed markers associated both with M1 and M2 phenotypes concurrently, suggesting the possibility of newly recruited macrophages responding even 12 weeks after implantation and/or a repetitive microinjury in which macrophages are continuously recruited and polarized without resolution of the host response. Biochemically, we observed a predominantly M1 pro-inflammatory signaling environment and decreased collagen content as a response to implanted mesh. This study evidences the importance of PPM mesh properties, which may alter mesh burden upon tensioning and impact downstream healing outcomes and emphasizes the need for devices that maintain their geometry following implantation in POP surgical repair.

Post-operative outcomes associated with anterior mesh location after laparoscopic sacrocolpopexy

OBJECTIVE

To investigate the relationship between the anatomical position of the anterior arm of the mesh, measured by ultrasound through the bladder neck-mesh distance technique and the surgical outcomes after laparoscopic sacrocolpopexy (SCP) for apical prolapse.

STUDY DESIGN

It was a retrospective analysis of prospectively collected data in a tertiary care hospital. Between January 2019 and September 2019, 63 women who underwent laparoscopic SCP due to apical prolapse were included. Bladder neck-mesh distance was measured immediately after surgery. The pelvic floor was evaluated using the Pelvic Organ Prolapse Quantification (POP-Q) System before, 1 month, and 2.7 years (mid-term) after the surgery. Post-operative stress urinary incontinence (SUI) and Patient Global Impression of Improvement (PGI-I) scores were also assessed. The correlation between bladder neck-mesh distance and the post-operative outcomes was investigated using the Spearman rank correlation coefficient.

RESULTS

At mid-term follow-up visit, bladder neck-mesh distance was inversely correlated with the correction of apical prolapse and post-operative SUI. No correlation was detected with the anterior compartment prolapse correction. PGI-I scores were high in all patients at mid-term follow-up, irrespective of bladder neck-mesh distance values.

CONCLUSION

The shorter the bladder neck-mesh distance, the better the outcome for apical compartment repair. Bladder neck-mesh distance had no correlation with the anterior anatomical correction. Shorter bladder neck-mesh distance values were positively correlated to better PGI-I scores and a higher risk of SUI.

Effect of anterior vaginal wall prolapse repair by modified transvaginal mesh surgery: a retrospective cohort study

OBJECTIVE

To explore clinical outcomes and complications of modified Transvaginal mesh (M-TVM) for advanced anterior vaginal wall prolapse in 1 year follow-up.

METHODS

574 patients underwent TVM surgeries from 2019 to 2020 were collected and divided into TVM group and M-TVM group, all preoperative and postoperative data was obtained and compared between the two groups.

RESULTS

285 women were involved eventually, including 181 in TVM group and 104 in M-TVM group. No significant difference of general conditions was found between these two groups. After long-term follow-up, patients in TVM group were more likely to suffer from pelvic pain than M-TVM group (P = 0.046). Meshes seemed much wider in M-TVM group (4.5 ± 0.69 cm) than in TVM group (3.0 ± 0.91 cm). No matter TVM or M-TVM, surgeries can significantly change point Aa and Ba when compared to preoperative data. Compared to TVM group, point C and D were significant changed in patients in M-TVM group after surgery (P < 0.001) CONCLUSION: M-TVM is a commendable procedure that can significant correct anterior prolapse with mesh extended wider, and also supply stable apical support at the same time.

Mesh Deformation: a mechanism underlying polypropylene prolapse mesh complications in vivo

Polypropylene meshes used in pelvic organ prolapse (POP) repair are hampered by complications. Most POP meshes are highly unstable after tensioning ex vivo, as evidenced by marked deformations (pore collapse and wrinkling) that result in altered structural properties and material burden. By intentionally introducing collapsed pores and wrinkles into a mesh that normally has open pores and remains relatively flat after implantation, we reproduce mesh complications in vivo. To do this, meshes were implanted onto the vagina of rhesus macaques in nondeformed (flat) vs deformed (pore collapse +/- wrinkles) configurations and placed on tension. Twelve weeks later, animals with deformed meshes had two complications, 1) mesh exposure through the vaginal epithelium, and 2) myofibroblast proliferation with fibrosis - a mechanism of pain. The overarching response to deformed mesh was vaginal thinning associated with accelerated apoptosis, reduced collagen content, increased proteolysis, deterioration of mechanical integrity, and loss of contractile function consistent with stress shielding - a precursor to mesh exposure. Regional differences were observed, however, with some areas demonstrating myofibroblast proliferation and matrix deposition. Variable mechanical cues imposed by deformed meshes likely induce these two disparate responses. Utilizing meshes associated with uniform stresses on the vagina by remaining flat with open pores after tensioning is critical to improving outcomes. STATEMENT OF SIGNIFICANCE: Pain and exposure are the two most reported complications associated with the use of polypropylene mesh in urogynecologic procedures. Most meshes have unstable geometries as evidenced by pore collapse and wrinkling after tensioning ex vivo, recapitulating what is observed in meshes excised from women with complications in vivo. We demonstrate that collapsed pores and wrinkling results in two distinct responses 1) mesh exposure associated with tissue degradation and atrophy and 2) myofibroblast proliferation and matrix deposition consistent with fibrosis, a tissue response associated with pain. In conclusion, mesh deformation leads to areas of tissue degradation and myofibroblast proliferation, the likely mechanisms of mesh exposure and pain, respectively. These data corroborate that mesh implantation in a flat configuration with open pores is a critical factor for reducing complications in mesh-augmented surgeries.

Imaging and Treatment of Complications of Abdominal and Pelvic Mesh Repair

Surgical mesh is used most frequently for tension-free repair of abdominal wall hernias in adults, because the rate of hernia recurrence is lower with mesh than with primary soft-tissue repair. Since the introduction of polypropylene mesh in the middle of the 20th century, many mesh materials and configurations for specific surgical procedures have been developed. In addition to abdominal wall hernia repair, mesh may be used for repair of diaphragmatic hernias, urinary incontinence in women (female slings), genitourinary prolapse (vaginal mesh and sacrocolpopexy), rectal prolapse (rectopexy), and postprostatectomy male urinary incontinence (male slings). General mesh repair complications include chronic pain; fluid collections such as seromas, hematomas, and abscesses; adhesions that may lead to intestinal blockage; erosion into solid or hollow viscera including enterocutaneous fistulizing disease; and mesh failure characterized by mesh shrinkage, detachment, and migration with repair malfunction. Several mesh complications are often diagnosed with imaging, primarily with CT and less frequently with MRI and US, despite variable mesh visibility at imaging. This article reviews the common surgical mesh applications in the abdomen and pelvis, discusses imaging of mesh repair complications, and provides complication treatment highlights.^©RSNA, 2020.

Meshy business: MRI and ultrasound evaluation of pelvic floor mesh and slings

Pelvic floor disorders are a complex set of conditions including but not limited to stress urinary incontinence and pelvic organ prolapse that generally affect older and multiparous women. Of the several surgical options available for treatment of these conditions, synthetic mid-urethral slings for stress urinary incontinence and vaginal mesh for pelvic organ prolapse are amenable to imaging evaluation by ultrasound and magnetic resonance imaging techniques. Ultrasound can evaluate the sub- and immediate peri-urethral portions of sling due to its ability to differentiate synthetic material from native tissues with real-time imaging, while MRI is able to better depict the global pelvic floor anatomy and assess the more distant components of mesh and slings material. Given the high prevalence of pelvic floor disorders and complications after surgical repair, it is important that radiologists familiarize themselves with normal and abnormal imaging findings after these procedures. This article provides a review of the spectrum of imaging findings in patients after pelvic floor repair with synthetic mid-urethral slings and vaginal mesh.

Ultrasound imaging of slings and meshes in urogynecology

Imaging is used increasingly in urogynecology. One of the main applications is in the assessment of synthetic implants. Ultrasound is particularly useful for this purpose as most such implants appear highly echogenic on ultrasound but are not visible using other imaging techniques. The worldwide success of synthetic mid-urethral slings, introduced in the late 90s, led to the subsequent introduction of transvaginal mesh in 2003-2004. Widespread use of synthetic implants for both urinary incontinence and prolapse has caused a rise in implant-related complications and increasing negative publicity and litigation, with many products removed from the market. It is not surprising that there is increasing demand for the assessment and evaluation of sling and mesh implants using imaging. This review article discusses the role of translabial/transperineal ultrasound in the evaluation of synthetic implants used in the treatment of urinary incontinence and pelvic organ prolapse. The discussion focuses on those applications of the technique that are useful for surgeons dealing with patients after mesh and/or sling placement. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Prospective ultrasonographic follow-up of transvaginal lightweight meshes: a 1-year multicenter study

INTRODUCTION AND HYPOTHESIS

The use of new lightweight meshes in pelvic organ prolapse (POP) surgery may reduce complications related to mesh retraction (chronic pain, dyspareunia, and mesh exposure). The aim of this study was to investigate changes in the area and position of Uphold Lite™ mesh 6 weeks and 12 months after anterior and/or apical prolapse repair.

METHODS

This observational prospective multicenter study included patients who had undergone transvaginal surgery for symptomatic POP-Q stage ≥ II anterior and/or apical compartment prolapse with placement of Uphold Lite mesh. The dimensions and position of the mesh were evaluated at 6 weeks and 12 months by ultrasonography. Correlations between ultrasonographic mesh characteristics and POP recurrence were analyzed.

RESULTS

Fifty evaluable women with an average age of 66.8 years were included. No statistically significant difference in mesh area was found between week 6 and month 12 postoperatively, either at rest (1746.92 vs. 1574.48 mm²; p = 0.15) or on Valsalva (1568.81 vs. 1542.98 mm²; p = 0.65). The ROC-AUC of the distance between the mesh and the bladder neck (M-BN) at 6 weeks for predicting cystocele recurrence at 12 months was 0.764 (95% CI 0.573-0.955) at rest and 0.724 (95% CI 0.533-0.916) on Valsalva. An M-BN distance > 12.5 mm could predict cystocele recurrence at month 12 with a sensitivity of 80% and a specificity of 69%.

CONCLUSIONS

Ultrasonographic measurements of the Uphold Lite™ mesh appear to remain stable between 6 weeks and 12 months postoperatively. M-BN distance correlates with cystocele recurrence. These results appear to confirm the value of ultrasound in mesh evaluation.

The Use of Imaging for Synthetic Midurethral Slings

Ultrasound and magnetic resonance imaging can be used to image midurethral slings, which have may have complications such as pain. There is considerable misunderstanding regarding the utility of the different modalities. This article aims to review the current literature to identify the benefits and limitations of each imaging modality and identify the place that each should have for patients with midurethral sling complications. A literature search was performed, and all relevant articles were identified and reviewed. Different imaging modalities are complementary, but more research is required in this area.

Laparoscopic sacrocolpopexy as the mainstay management for significant apical pelvic organ prolapse (LAP) study

STUDY OBJECTIVES

The primary aim of this study was to assess the clinical feasibility of a policy where laparoscopic sacrocolpopexy (LSC) is the default procedure for the management of a significant apical pelvic organ prolapse (a-POP). As a secondary aim, we wanted to evaluate LSC outcomes in relation to women's preoperative assessment of their surgical fitness using the American Society of Anesthesiologists physical status (ASA-PS) categorization.

DESIGN

Retrospective cohort study.

SETTING

A university affiliated urogynecology center.

METHODS

All women with symptomatic a-POP (C ≥ -1) who attended the urogynecology clinic between the 1^st of January and the 31^st of December 2016 and had their surgery by the 31^st of May 2017 were included in the study. In our unit, routine follow-up appointments are arranged at 3 and 12 months post LSC.

INTERVENTIONS

Perioperative and mesh-related complications were assessed based on the Dindo-Clavien and IUGA/ICS classifications respectively. The preoperative outcome measures included Pelvic Organ Prolapse Quantification (POP-Q) stage, Pelvic Floor Distress Inventory (PFDI) and ASA-PS score. At follow-up women were asked to complete a PFDI, Patient Global Impression of Improvement (PGI-I), had their POP-Q staging and ultrasonographic assessment of mesh position and placement. The above measures are routinely collected as part of our standard practice. A preoperative ASA-PS score of <3 was used as a cut-off to dichotomies participants into low and high risk.

MAIN RESULTS

A total of 220 women attended our center during the study period because of POP. Of these, 146 women were diagnosed with a significant a-POP and 142 (97.2 %) women opted for a surgical repair. Of the 142 women, 128 (90.1 %) were deemed suitable for a type of LSC and 121 had their surgery before the 31^st of May 2017. There were no statistically significant differences in any of our collected perioperative, clinical, patient reported or ultrasonographic outcome measures when comparing women with ASA-PS scores of <3 or ≥3.

CONCLUSION

In a specialized urogynecology healthcare setting, it is feasible and safe to rely on LSC as the mainstay surgical procedure for the repair of a significant a-POP. However, it is imperative to ensure that technical skills and equipment requirements are fulfilled and maintained.

New Zealand white rabbit: a novel model for prolapse mesh implantation via a lumbar colpopexy

INTRODUCTION AND HYPOTHESIS

New Zealand white rabbits are an inexpensive large-animal model. This study explored the rabbit as a model for mesh-augmented colpopexy using the intra-abdominal vagina. We hypothesized that polypropylene mesh would negatively impact rabbit vaginal smooth muscle (VSM) morphology and contractile function, similar to the nonhuman primate (NHP)-the established model for prolapse mesh evaluation.

METHODS

Restorelle was implanted onto the vagina of ten rabbits via lumbar colpopexy after a hysterectomy. Ten rabbits served as sham. Twelve weeks post-implantation, the vagina was excised and VSM morphology and vaginal contractility were assessed. Outcome measures were compared using independent samples t and Mann-Whitney U tests with a Bonferroni correction, where appropriate. Results from the rabbits were compared with published NHP data.

RESULTS

Animals had similar age, parity and BMI. VSM was 18% thinner after Restorelle implantation, P = 0.027. Vaginal contractility was 43% decreased in response to 120 mM KCl (P = 0.003), similar to the 46% reduction observed in the NHP vagina implanted with Restorelle (P = 0.027). Three meshes wrinkled in vivo, resulting in dramatic thinning of the underlying vagina in the area of the mesh causing a mesh exposure.

CONCLUSIONS

Polypropylene mesh negatively impacts VSM morphology and vaginal contractility in the rabbit, similar to the NHP, suggesting that the rabbit may serve as an alternative large-animal model. The vaginal thinning and appearance of a mesh exposure in the area of a mesh wrinkle suggest the rabbit may also serve as a model for understanding the pathophysiology of mesh exposure.

Obesity and its long-term impact on sacrocolpopexy key outcomes (OBELISK)

INTRODUCTION AND HYPOTHESIS

Sacrocolpopexy is the preferred contemporary approach to managing significant apical pelvic organ prolapse. Obesity is an established risk factor for several surgical procedures and can have a negative impact on outcomes. Our goal was to evaluate the impact of BMI on the safety and efficacy of laparoscopic sacrocolpopexy in women with pelvic organ prolapse.

METHODS

A single-center retrospective observational study of women undergoing laparoscopic sacrocolpopexy between January 1, 2015, and December 31, 2017.

RESULTS

We found 299 procedures: 82 (27.4%), 147 (49.2%) and 70 (23.4%) in women with BMI <25 (normal weight), BMI ≥ 25 - < 30 (overweight) and BMI ≥ 30 (obese), respectively. Perioperative and early postoperative complications were generally low and not statistically significantly different between the groups. At 12 months postoperatively, 81 (98.8%), 136 (92.5%) and 62 (88.6%) normal-weight, overweight and obese women attended their follow-up, respectively. All obese women attending the follow-up scored an overall Patient Global Impression of Improvement (PGI-I) of ≤ 3. The Pelvic Floor Distress Inventory (PFDI) scores showed a significant improvement in all domains and were similar between the study groups. In total, there was one (0.4%) anatomical apical compartment failure, three (1.1%) anterior compartment failures and two (0.7%) posterior compartment failures with no significant differences between the groups. Similarly, there were no differences in functional outcomes or mesh position as assessed by ultrasound.

CONCLUSIONS

There were no differences in surgical, short- and long-term outcomes of laparoscopic sacrocolpopexy for pelvic organ prolapse in obese compared with non-obese women.

3D reconstruction of MR-visible Fe3 O4 -mesh implants: Pelvic mesh measurement techniques and preliminary findings

AIMS

To develop MR-based measurement technique to evaluate the postoperative dimension and location of implanted magnetic resonance (MR)-visible meshes.

METHODS

This technique development study reports findings of six patients (A-F) with cystoceles treated with anterior vaginal MR-visible Fe₃ O₄ -polypropylene implants. Implanted meshes were reconstructed from 3 months and/or 1 year postsurgical MR-images using 3D Slicer®. Measurements including mesh length, distance to the ischial spines, pudendal, and obturator neurovascular bundles and urethra were obtained using software Rhino® and a custom Matlab® program. The range of implanted mesh length and their placements were reported and compared with mesh design and implantation recommendations. With the anterior/posterior-mesh-segment-ratio mesh shrinkage localization was evaluated.

RESULTS

Examinations were possible for patients A-D 3 months and for A, C, E, and F 1 year postsurgical. The mesh was at least 40% shorter in all patients 3 months and/or 1 year postoperatively. A, B showed shrinkage in the anterior segment, D, E in the posterior segment (Patients C, F not applicable due to intraoperative mesh trimming). Patient E presented pain in the area of mesh shrinkage. In Patient C posterior mesh fixations were placed in the iliococcygeal muscle rather than sacrospinous ligaments. Arm placement less than 20 mm from the pudendal neurovascular bundles was seen in all cases. The portion of the urethra having mesh underneath it ranged from 19% to 55%.

CONCLUSIONS

MRI-based measurement techniques have been developed to quantify implanted mesh location and dimension. Mesh placement variations possibly correlating with postoperative complications can be illustrated.

Ultrasound visualization of sacrocolpopexy polyvinylidene fluoride meshes containing paramagnetic Fe particles compared with polypropylene mesh

INTRODUCTION AND HYPOTHESIS

Paramagnetic Fe particles can be added during synthetic mesh production to allow visibility on magnetic resonance imaging. Our aim was to evaluate whether transperineal ultrasound (TPUS) allows visualization, measurement, and characterization of polyvinylidene fluoride (PVDF mesh) containing Fe particles compared with regular polypropylene (PP) meshes used for sacrocolpopexy.

METHODS

Women up to 1.5 years after laparoscopic sacrocolpopexy who were implanted with a PP or PVDF mesh underwent clinical examination and 2D, 3D, and 4D TPUS. Acquired volumes were analyzed offline for mesh position at rest and maximal Valsalva and for mesh dimensions and characteristics, with the operator blinded to group assignment. The two groups were compared.

RESULTS

There were 17 women in the PP and 25 in the PVDF mesh group, without differences in baseline demographics. None had significant prolapse, recurrence, symptoms, or complications. On TPUS, mesh was visible in all patients both caudally (perineal) and cranially but was more echogenic in the PVDF mesh group. Mesh length from distal to proximal that was visible on TPUS was longer for PVDF mesh, for both anterior and posterior vaginal arms (all P < 0.05), and for mesh above the vaginal apex (P = 0.002). The inferior aspects of the mesh showed areas of double mesh layers, suggesting folding in 80% of women in both groups, without symptoms.

CONCLUSIONS

PVDF mesh permits clearer visualization and is seen over a longer stretch on TPUS, with longer visible mesh arms. The latter can be due to differences in operative technique, presence of microparticles, implant textile structure, or patient characteristics.

Ultrasound in the assessment of pelvic organ prolapse

Imaging is increasingly being used in urogynaecology. Because of low cost and universal availability, ultrasound (US) is the most commonly used diagnostic modality, which allows the observation of manoeuvres such as Valsalva and pelvic floor muscle contraction in real time. The ability to see beyond surface anatomy is particularly important in the posterior compartment and in obstructed defecation where this method may replace defecation proctography. Imaging is especially useful in the form of 3D/4D multiplanar and tomographic translabial US, as these modalities give access to the axial plane and the levator ani. This allows assessment of both avulsion, i.e. major maternal birth trauma, and hiatal overdistension, i.e. ballooning. Both are major risk factors for both prolapse and prolapse recurrence. This review will outline current clinical utility, introduce recent research in the respective field and provide an overview of likely future utility of imaging in the investigation of pelvic organ prolapse.

Short term post-operative morphing of sacrocolpopexy mesh measured by magnetic resonance imaging

BACKGROUND

Sacrocolpopexy (SC) involves suspension of the vaginal vault or cervix to the sacrum using a mesh. Following insertion, the meshes have been observed to have undergone dimensional changes.

OBJECTIVE

To quantify dimensional changes of meshes following implantation and characterize their morphology in-vivo.

DESIGN SETTING AND PARTICIPANTS

24 patients underwent SC using PolyVinyliDeneFluoride mesh loaded with Fe₃O₄ particles. Tailored anterior and posterior mesh flaps were sutured to the respective vaginal walls, uniting at the apex. The posterior flap continued to the sacrum and was attached there. Meshes were visualized on magnetic resonance (MR) imaging at 12 [3-12] (median [range]) months postoperatively and 3D models of the mesh were generated. Dynamic MR sequences were acquired during valsalva to record mesh mobility.

OUTCOME MEASURES

The area of the vagina effectively supported by the mesh (Effective Support Area (ESA)) was calculated. The 3D models' wall thickness map was analyzed to identify the locations of mesh folding. Intraclass correlation (ICC) was calculated to test the reliability of the methods. To measure the laxity and flatness of the mesh, the curvature and the ellipticity of the sacral flap were calculated.

RESULTS

The ESA calculation methodology had ICC = 0.97. A reduction of 75.49 [61.55-78.67] % (median [IQR]) in area, 47.64 [38.07-59.81] % in anterior flap, and of 23.95 [10.96-27.21] % in the posterior flap was measured. The mesh appeared thicker near its attachment at the sacral promontory (n = 19) and near the vaginal apex (n = 22). The laxity of the mesh was 1.13 [1.10-1.16] and 60.55 [49.76-76.25] % of the sacral flap was flat. We could not reliably measure mesh mobility (ICC = 0.16).

CONCLUSION

A methodology for complete 3D characterization of SC meshes using MR images was presented. After implantation, the supported area is much lower than what is prepared prior to implantation. We propose this happened during the surgery itself.

Long-term follow-up of sacrocolpopexy mesh implants at two time intervals at least 1 year apart using 4D transperineal ultrasound

OBJECTIVE

To determine, using four-dimensional (4D) transperineal ultrasound, whether the appearance, position or dimensions of sacrocolpopexy mesh implants or the degree of tissue support change in the long term.

METHODS

Women who had undergone minimally invasive abdominal sacrocolpopexy for pelvic organ prolapse were invited for follow-up assessment at two consecutive visits at least 1 year apart. All participants completed a Pelvic Floor Distress Inventory questionnaire (PFDI-20) and underwent a pelvic examination by one examiner and had 4D ultrasound volumes obtained by a different examiner. Volumes were analyzed offline for mesh position with the woman at rest and on maximal Valsalva maneuver, and for mesh dimensions and characteristics on three-dimensional orthogonal planes and rendered views, with the operator blinded to the clinical data. Findings were compared between the two examinations.

RESULTS

Thirty women attended follow-up assessment at two time points, a median of 22 (range, 12-37) months apart. The median age at the latter visit was 60 (range, 46-72) years, median body mass index was 25.9 (range, 20.8-31.9) kg/m² , median parity was 3 (range, 1-7) and median time from surgery to first and second visit, respectively, was 11.2 (range, 6-26) months and 33.5 (range, 14-56) months. There were no significant differences between the two time points in symptom scores, reported satisfaction from surgery, pelvic examination findings or pelvic organ descent in any compartment according to ultrasound. While mesh dimensions of anterior and posterior arms did not change significantly over time, both arms descended less on Valsalva at the second follow-up compared with at the first (13.2 ± 6.7 mm vs 21.9 ± 10.0 mm and 9.1 ± 5.3 mm vs 16.1 ± 8.1 mm, respectively, both P < 0.001). There were no mesh erosions, but folding remained a consistent finding, occurring in 80% of women in each assessment.

CONCLUSIONS

Characteristics of tissue support and dimensions of sacrocolpopexy mesh implants remained constant over long-term follow-up, with no mesh shrinkage or erosion. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

In Vivo Ultrasound Characteristics of Vaginal Mesh Kit Complications

OBJECTIVE

The objective of this study was to investigate the ultrasound characteristics of vaginal mesh in women with vaginal mesh complications.

METHODS

This was a cross-sectional study of women presenting with extrusion complications from vaginal mesh kit for prolapse at our tertiary care center between years 2009 and 2014. We included women who concurrently underwent a 3-dimensional endovaginal ultrasound (EVUS) as part of the clinical evaluation. We excluded women with incomplete charts and poor imaging quality. Subjects were categorized by the presence or absence of associated pelvic pain. Based on ultrasound findings, we compared the location of mesh, the appearance of mesh pattern (flat, folding, prominence, convoluted), and other EVUS characteristics of mesh.

RESULTS

Forty-six women with vaginal mesh complications and good image quality were included. When comparing mesh length between posterior and anterior compartments, the posterior meshes were significantly longer than the anterior meshes (42.1 [SD, 11.9] mm vs 25.8 [SD, 9] mm; P < 0.0001) and more often associated with pain. In the posterior compartment, the mean mesh length seen on EVUS was significantly longer in women with pain than in women without pain (46.5 [SD, 9] mm vs 31.8 [SD, 12.1] mm; P = 0.0001). There was also a higher proportion of a "flat" mesh pattern, 14 (58.3%) of 25, in the posterior compartment associated with the presence of pain (P = 0.013). In the posterior compartment, a smaller distance between the distal edge of the mesh and the anal sphincter was significantly associated with the presence of pain (8 mm [0-37] vs 21 mm [8-35], P = 0.024). In both compartments, the EVUS had 100% sensitivity for detection of mesh extrusions.

CONCLUSIONS

In this population of patients presenting with mesh complications, the posterior meshes were more often visualized as a "flat" pattern with a higher frequency of pain. Mesh complications of the anterior compartment had a higher frequency of folding and shrinkage.

Ultrasound imaging in urogynecology - state of the art 2016

The role of ultrasound imaging in urogynecology is not clearly defined. Despite significant developments in visualization techniques and interpretation of images, pelvic ultrasound is still more a tool for research than for clinical practice. Structures of the lower genitourinary tract and pelvic floor can be visualized from different approaches: transperineal, introital, transvaginal, abdominal or endoanal. According to contemporary guidelines and recommendations, the role of ultrasound in urogynecology is limited to the measurement of post-void residue. However, in many instances, including planning and audit of surgical procedures, management of recurrences or complications, ultrasound may be proposed as the initial examination of choice. Ultrasound may be used for assessment of bladder neck mobility before anti-incontinence procedures. On rare occasions it is helpful in recognition of pathologies mimicking vaginal prolapse such as vaginal cyst, urethral diverticula or rectal intussusception. In patients subjected to suburethral slings, causes of surgery failure or postsurgical voiding dysfunctions can be revealed by imaging. Many reports link the location of a tape close to the bladder neck to unfavorable outcomes of sling surgery. Some postoperative complications, such as urinary retention, mesh malposition, hematoma, or urinary tract injury, can be diagnosed by ultrasound. On the other hand, the clinical value of some applications of ultrasound in urogynecology, for example measurement of the bladder wall thickness as a marker of detrusor overactivity, has not been proved.

Diagnosis and Therapy of Female Pelvic Organ Prolapse. Guideline of the DGGG, SGGG and OEGGG (S2e-Level, AWMF Registry Number 015/006, April 2016)

Aims: The aim was to establish an official interdisciplinary guideline, published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). The guideline was developed for use in German-speaking countries. In addition to the Germany Society of Gynecology and Obstetrics, the guideline has also been approved by the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). This is a guideline published and coordinated by the DGGG. The aim is to provide evidence-based recommendations obtained by evaluating the relevant literature for the diagnostic, conservative and surgical treatment of women with female pelvic organ prolapse with or without stress incontinence. Methods: We conducted a systematic review together with a synthesis of data and meta-analyses, where feasible. MEDLINE, Embase, Cinahl, Pedro and the Cochrane Register were searched for relevant articles. Reference lists were hand-searched, as were the abstracts of the Annual Meetings of the International Continence Society and the International Urogynecological Association. We included only abstracts of randomized controlled trials that were presented and discussed in podium sessions. We assessed original data on surgical procedures published since 2008 with a minimum follow-up time of at least 12 months. If the studies included descriptions of perioperative complications, this minimum follow-up period did not apply. Recommendations: The guideline encompasses recommendations for the diagnosis and treatment of female pelvic organ prolapse. Recommendations for anterior, posterior and apical pelvic organ prolapse with or without concomitant stress urinary incontinence, uterine preservation options, and the pros and cons of mesh placements during surgery for pelvic organ prolapse are presented. The recommendations are based on an extensive and systematic review and evaluation of the current literature and include the experiences and specific conditions in Germany, Austria and Switzerland.

Textile properties of synthetic prolapse mesh in response to uniaxial loading

BACKGROUND

Although synthetic mesh is associated with superior anatomic outcomes for the repair of pelvic organ prolapse, the benefits of mesh have been questioned because of the relatively high complication rates. To date, the mechanisms that result in such complications are poorly understood, yet the textile characteristics of mesh products are believed to play an important role. Interestingly, the pore diameter of synthetic mesh has been shown to impact the host response after hernia repair greatly, and such findings have served as design criteria for prolapse meshes, with larger pores viewed as more favorable. Although pore size and porosity are well-characterized before implantation, the changes in these textile properties after implantation are unclear; the application of mechanical forces has the potential to greatly alter pore geometries in vivo. Understanding the impact of mechanical loading on the textile properties of mesh is essential for the development of more effective devices for prolapse repair.

OBJECTIVE

The objective of this study was to determine the effect of tensile loading and pore orientation on mesh porosity and pore dimensions.

STUDY DESIGN

In this study, the porosity and pore diameter of 4 currently available prolapse meshes were examined in response to uniaxial tensile loads of 0.1, 5, and 10 N while mimicking clinical loading conditions. The textile properties were compared with those observed for the unloaded mesh. Meshes included Gynemesh PS (Ethicon, Somerville, NJ), UltraPro (Artisyn; Ethicon), Restorelle (Coloplast, Minneapolis, MN), and Alyte Y-mesh (Bard, Covington, GA). In addition to the various pore geometries, 3 orientations of Restorelle (0-, 5-, 45-degree offset) and 2 orientations of UltraPro (0-, 90-degree offset) were examined.

RESULTS

In response to uniaxial loading, both porosity and pore diameter dramatically decreased for most mesh products. The application of 5 N led to reductions in porosity for nearly all groups, with values decreasing by as much as 87% (P < .05). On loading to 10 N of force, nearly all mesh products that were tested were found to have porosities that approached 0% and 0 pores with diameters >1 mm.

CONCLUSION

In this study, it was shown that the pore size of current prolapse meshes dramatically decreases in response to mechanical loading. These findings suggest that prolapse meshes, which are more likely to experience tensile forces in vivo relative to hernia repair meshes, have pores that are unfavorable for tissue integration after surgical tensioning and/or loading in urogynecologic surgeries. Such decreases in pore geometry support the hypothesis that regional increases in the concentration of mesh leads to an enhanced local foreign body response. Although pore deformation in transvaginal meshes requires further characterization, the findings presented here provide a mechanical understanding that can be used to recognize potential areas of concern for complex mesh geometries. Understanding mesh mechanics in response to surgical and in vivo loading conditions may provide improved design criteria for mesh and a refinement of surgical techniques, ultimately leading to better patient outcomes.

Host response to synthetic mesh in women with mesh complications

BACKGROUND

Despite good anatomic and functional outcomes, urogynecologic polypropylene meshes that are used to treat pelvic organ prolapse and stress urinary incontinence are associated with significant complications, most commonly mesh exposure and pain. Few studies have been performed that specifically focus on the host response to urogynecologic meshes. The macrophage has long been known to be the key cell type that mediates the foreign body response. Conceptually, macrophages that respond to a foreign body can be dichotomized broadly into M1 proinflammatory and M2 proremodeling subtypes. A prolonged M1 response is thought to result in chronic inflammation and the formation of foreign body giant cells with potential for ongoing tissue damage and destruction. Although a limited M2 predominant response is favorable for tissue integration and ingrowth, excessive M2 activity can lead to accelerated fibrillar matrix deposition and result in fibrosis and encapsulation of the mesh.

OBJECTIVE

The purpose of this study was to define and compare the macrophage response in patients who undergo mesh excision surgery for the indication of pain vs a mesh exposure.

STUDY DESIGN

Patients who were scheduled to undergo a surgical excision of mesh for pain or exposure at Magee-Womens Hospital were offered enrollment. Twenty-seven mesh-vagina complexes that were removed for the primary complaint of a mesh exposure (n = 15) vs pain in the absence of an exposure (n = 12) were compared with 30 full-thickness vaginal biopsy specimens from women who underwent benign gynecologic surgery without mesh. Macrophage M1 proinflammatory vs M2 proremodeling phenotypes were examined via immunofluorescent labeling for cell surface markers CD86 (M1) vs CD206 (M2) and M1 vs M2 cytokines via enzyme-linked immunosorbent assay. The amount of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) proteolytic enzymes were quantified by zymography and substrate degradation assays, as an indication of tissue matrix degradation. Statistics were performed with the use of 1-way analysis of variance with appropriate post hoc tests, t-tests, and Fisher's Exact test.

RESULTS

Twenty-seven mesh-vaginal tissue complexes were excised from 27 different women with mesh complications: 15 incontinence mid urethral slings and 12 prolapse meshes. On histologic examination, macrophages surrounded each mesh fiber in both groups, with predominance of the M1 subtype. M1 and M2 cytokines/chemokines, MMP-9 (pro- and active), and MMP-2 (active) were increased significantly in mesh-vagina explants, as compared with vagina without mesh. Mesh explants that were removed for exposure had 88.4% higher pro-MMP-9 (P = .035) than those removed for pain. A positive correlation was observed between the profibrotic cytokine interleukin-10 and the percentage of M2 cells (r = 0.697; P = .037) in the pain group.

CONCLUSION

In women with complications, mesh induces a proinflammatory response that persists years after implantation. The increase in MMP-9 in mesh explants that were removed for exposure indicates degradation; the positive association between interleukin-10 and M2 macrophages in mesh explants that are removed for pain is consistent with fibrosis.

Biomechanical, Topological and Chemical Features That Influence the Implant Success of an Urogynecological Mesh: A Review

Synthetic meshes are normally used to treat several diseases in the field of urogynecological surgery. Not-optimal selection of mesh and/or its not-correct implant may increase patient's pain and discomfort. The knowledge of mechanical behaviour and topological and chemical properties of a mesh plays a fundamental role to minimize patient's suffering and maximize the implant success. We analysed several papers reporting the meshes application for urogynecological pathologies, to extrapolate the principal parameters that normally are used to characterise the biomechanical, topological, and chemical properties, and to verify their influence on implant success. In this way we want demonstrate that, knowing these features, it is possible to foresee the success of a mesh implant. This review shows that the application of a mesh strictly depends on elastic modulus, failure load, porosity and pore size, filament diameter, polymer weight, and crystallinity. To increase the success of the implant and to help choice of optimal mesh for a clinical need, two indexes have been proposed for comparing, in an easier way, the mechanical performance of different commercially available meshes.

Role of ultrasound imaging in advancing treatment of female patients with pelvic floor mesh complications

Application of vaginal mesh for stress urinary incontinence has seen widespread use due to its relatively short operative time in combination with its efficacy in treatment. However, vaginal mesh is not without its drawbacks and can lead to mesh erosion or extrusion, infection, dyspareunia, and recurrence of incontinence. Vaginal mesh complications can lead to feelings of hopelessness, isolation, shame, and emotional distress. Furthermore, failure to identify and address these complications in a timely manner can be permanently damaging to patient health. It is vital to be able to identify mesh complications early. Various imaging methodologies exist to visualize vaginal mesh placement and complications, including ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT). This invited review paper focuses on the role of ultrasound in mesh visualization, mesh complication identification, and operative planning in the event of subsequent surgical mesh revision. Polypropylene mesh is echogenic on ultrasound, making it a useful tool for visualizing post-operative mesh placement. Transperineal, translabial and endovaginal ultrasound technique use has been described in the pre- and peri-operative setting to identify mesh in complex cases. Efficacy and practicality of CT and MRI use in identifying mesh in these cases is limited.

Emerging Trends in Abdominal Wall Reinforcement: Bringing Bio-Functionality to Meshes

Abdominal wall hernia is a recurrent issue world-wide and requires the implantation of over 1 million meshes per year. Because permanent meshes such as polypropylene and polyester are not free of complications after implantation, many mesh modifications and new functionalities have been investigated over the last decade. Indeed, mesh optimization is the focus of intense development and the biomaterials utilized are now envisioned as being bioactive substrates that trigger various physiological processes in order to prevent complications and to promote tissue integration. In this context, it is of paramount interest to review the most relevant bio-functionalities being brought to new meshes and to open new avenues for the innovative development of the next generation of meshes with enhanced properties for functional abdominal wall hernia repair.

Three-dimensional analysis of implanted magnetic-resonance-visible meshes

OBJECTIVE

Our primary objective was to develop relevant algorithms for quantification of mesh position and 3D shape in magnetic resonance (MR) images.

METHODS

In this proof-of-principle study, one patient with severe anterior vaginal wall prolapse was implanted with an MR-visible mesh. High-resolution MR images of the pelvis were acquired 6 weeks and 8 months postsurgery. 3D models were created using semiautomatic segmentation techniques. Conformational changes were recorded quantitatively using part-comparison analysis. An ellipticity measure is proposed to record longitudinal conformational changes in the mesh arms. The surface that is the effective reinforcement provided by the mesh is calculated using a novel methodology. The area of this surface is the effective support area (ESA).

RESULTS

MR-visible mesh was clearly outlined in the images, which allowed us to longitudinally quantify mesh configuration between 6 weeks and 8 months after implantation. No significant changes were found in mesh position, effective support area, conformation of the mesh's main body, and arm length during the period of observation. Ellipticity profiles show longitudinal conformational changes in posterior arms.

CONCLUSIONS

This paper proposes novel methodologies for a systematic 3D assessment of the position and morphology of MR-visible meshes. A novel semiautomatic tool was developed to calculate the effective area of support provided by the mesh, a potentially clinically important parameter.

The impact of boundary conditions on surface curvature of polypropylene mesh in response to uniaxial loading

Exposure following pelvic organ prolapse repair has been observationally associated with wrinkling of the implanted mesh. The purpose of this study was to quantify the impact of variable boundary conditions on the out-of-plane deformations of mesh subjected to tensile loading. Using photogrammetry and surface curvature analyses, deformed geometries were accessed for two commercially available products. Relative to standard clamping methods, the amount of out-of-plane deformation significantly increased when point loads were introduced to simulate suture fixation in-vivo. These data support the hypothesis that regional increases in the concentration of mesh potentially enhance the host׳s foreign body response, leading to exposure.

Comparison between Elevate anterior/apical system and Perigee system in pelvic organ prolapse surgery: clinical and sonographic outcomes

OBJECTIVE

The aim of this study was to assess the incidence of de novo stress urinary incontinence (SUI) and sonographic features of implanted transvaginal mesh in continent women treated with Elevate(™) anterior/apical [single-incision mesh (SIM-A)] or Perigee(™) [transvaginal mesh with sacrospinous fixation (TVM + SSF)] in extensive pelvic organ reconstruction surgery.

METHODS

This prospective observational study was done from May 2010 to January 2013. Patients were recruited from two tertiary centers, and the Elevate(™) and Perigee(™) systems were compared. Patients who had overt or occult SUI, previous prolapse or mesh insertion were excluded.

RESULT

Fifty-seven patients in the SIM-A group and sixty-one in the TVM + SSF group were analysed. All completed a minimum of 1-year follow-up. Groups were demographically and statistically similar. There was a significantly high incidence of de novo SUI postoperatively in the SIM-A group. The objective and subjective cure rate of pelvic organ prolapse (POP) were comparable between groups, with incidence of mesh erosion in the SIM-A group and three in the TVM + SSF group. Sonographic evaluation showed significant increase in mesh length in the SIM-A group.

CONCLUSION

Elevate(™) a offered lower incidence of mesh erosion and comparable results on anatomical POP correction; however, incidence of de novo SUI was high. There is an apparent lengthening of implanted Elevate® mesh sonographically.

Imaging of slings and meshes

The popularity of imaging in pelvic floor medicine continues to increase. Among the various modalities, ultrasound is superior as it is cheap, safe, easily accesible and simple, resulting in high patient compliance. It is the only technique that allows imaging of modern wide-weave polypropylene sling or mesh implants, and imaging of such implants is commonly required due to the popularity of surgical techniques that involve the placement of slings and meshes. This review article will discuss the role of translabial ultrasound in the evaluation of synthetic implants used in the treatment of urinary incontinence and pelvic organ prolapse.

Outcome of transvaginal mesh and tape removed for pain only

PURPOSE

Because there is reluctance to operate for pain, we evaluated midterm outcomes of vaginal mesh and synthetic suburethral tape removed for pain as the only indication.

MATERIALS AND METHODS

After receiving institutional review board approval we reviewed a prospective database of women without a neurogenic condition who underwent surgery for vaginal mesh or suburethral tape removal with a focus on pain as the single reason for removal and a minimum 6-month followup. The primary outcome was pain level assessed by a visual analog scale (range 0 to 10) at baseline and at each subsequent visit with the score at the last visit used for analysis. Parameters evaluated included demographics, mean time to presentation and type of mesh or tape inserted.

RESULTS

From 2005 to 2013, 123 patients underwent surgical removal of mesh (69) and suburethral tape (54) with pain as the only indication. Mean followup was 35 months (range 6 to 59) in the tape group and 22 months (range 6 to 47) in the mesh group. The visual analog scale score decreased from a mean preoperative level of 7.9 to 0.9 postoperatively (p = 0.0014) in the mesh group and from 5.3 to 1.5 (p = 0.00074) in the tape group. Pain-free status, considered a score of 0, was achieved in 81% of tape and 67% of mesh cases, respectively. No statistically significant difference was found between the groups.

CONCLUSIONS

When pain is the only indication for suburethral tape or vaginal mesh removal, a significant decrease in the pain score can be durably expected after removal in most patients at midterm followup.

Three-dimensional transperineal ultrasound for imaging mesh implants following sacrocolpopexy

OBJECTIVE

To characterize, using three-dimensional (3D) transperineal ultrasound, the appearance, position and dimensions of mesh implants following minimally invasive abdominal sacrocolpopexy.

METHODS

In women who underwent sacrocolpopexy, mesh was evaluated at rest and on maximal Valsalva, on all 3D orthogonal planes and rendered views. Mesh dimensions were obtained by 3D processing in the midsagittal and coronal planes (anterior, posterior and sacral arm) and were analyzed offline, the operator blinded to clinical data.

RESULTS

Overall, 62 women, mean age 58.4 (range, 42-79) years were evaluated at a median of 9 (range, 1-26) months following surgery. The anterior arm of the mesh was caudal to the lowermost point of descent of the anterior compartment in 56 (90.3%) women, was equally positioned in five (8.1%) and was cranial in one. The posterior arm was caudal in 44 (71%) women, was equally positioned in 16 (25.8%) and was cranial in two (3.2%). The Y connection and the sacral arm of the mesh could not be adequately seen because of physical limitations of ultrasound (lower resolution at greater depth), large recurrent rectoceles, echogenic stools or folding of mesh remnants. Folding of the mesh was seen in 46 (74.2%) women, folding of the anterior arm in five (8.1%) and folding of the posterior arm in 23 (37.1%). Folding occurred caudally in 26 (41.9%) women, proximally in 11 (17.7%) and in both areas in nine (14.5%). There were no erosions.

CONCLUSION

Mesh visualization following minimally invasive abdominal sacrocolpopexy procedures using transperineal 3D/four-dimensional (4D) ultrasound is feasible. Studies are needed to evaluate the correlation between ultrasound measures and prolapse recurrence or mesh erosion.

Effectiveness of Hyalobarrier and Seprafilm to prevent polypropylene mesh shrinkage: a macroscopic and histological experimental study

INTRODUCTION AND HYPOTHESIS

Polypropylene (PP) mesh shrinkage represents a serious complication, as a significant cause of pain and recurrence of pelvic organ prolapse or ventral hernias, frequently requiring several surgical interventions. The retraction seems to be caused by the host, in response to the implantation, through the occurrence of periprosthetic adhesions and fibrosis. We hypothesized that avoiding the postoperative adhesions can prevent PP mesh shrinkage.

METHODS

Sixty rats were randomly assigned to three groups. A standardized hernia defect was induced on the abdominal wall, which was repaired using an extraperitoneal PP mesh alone (group 1), with application of a hyaluronate carboxymethylcellulose-based bioresorbable membrane (Seprafilm, group 2), or an auto-cross-linked polysaccharide hyaluronan-based solution (Hyalobarrier gel, group 3). Eight weeks after the procedure, a repeat laparotomy was performed. After scoring the adhesion and measuring the mesh surface, a microscopic study of the prosthesis-host tissue interfaces was performed.

RESULTS

Group 1 displayed a median shrinkage of 29% of the mesh. The Seprafilm group (p = 0.0238) and Hyalobarrier gel group (p = 0.0072) displayed a significantly smaller reduction of 19.12 and 17 %, respectively. Control group 1 displayed a significantly greater adhesion score (30.40) than the Seprafilm (11.67, p = 0.0028) and Hyalobarrier gel groups (11.19, p = 0.0013). The fibrosis was reduced in the Hyalobarrier gel group only.

CONCLUSION

This experimental study revealed that Hyalobarrier gel and Seprafilm can prevent PP mesh shrinkage and postoperative adhesions. They might be integrated in a mesh size-saving strategy, which should preserve the quality and durability of the surgical repair and limit the postoperative pain.

Three-dimensional endovaginal sonography of synthetic implanted materials in the female pelvic floor

The objective of this pictorial essay is to emphasize the ability of 3-dimensional endovaginal sonography to image synthetic implanted materials in the female pelvic floor. Implanted materials discussed in this pictorial essay include polypropylene vaginal mesh, polypropylene suburethral slings, and urethral bulking agents. Three-dimensional endovaginal sonography allows for more detailed imaging compared to computed tomography and magnetic resonance imaging of the female pelvic floor, in that each plane can be manipulated to show unique images of synthetic implanted materials.