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Ockrim J, Kearney R, Carolina Ochoa D, Hashim H, Van Koeveringe G, Chermansky C, Cardozo L, Wein A, Abrams P. Which parameters, related to the female urethra and pelvic floor, determine therapy selection for recurrent female stress urinary incontinence: ICI-RS 2023? Neurourol Urodyn 2024; 43:1372-1380. [PMID: 37937374 DOI: 10.1002/nau.25327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 10/24/2023] [Indexed: 11/09/2023]
Abstract
INTRODUCTION The evidence basis for therapy selection in women who have failed primary stress urinary incontinence (SUI) surgery is limited. The ICI-RS group discussed the available data at its meeting in June 2023, particularly the anatomical characteristics as assessed using magnetic resonance imaging (MRI) and ultrasound (US) modalities, functional characteristics associated with storage and voiding urodynamic assessment, as well as the patient characteristics that might influence outcomes. This paper summarizes the evidence base that supported these discussions and offers the basis for research proposals for future groups. METHODS A literature search of MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials was performed, and the data is presented. Research questions are based on the knowledge gaps highlighted. RESULTS Possible MRI parameters that may influence outcomes were striated urethral sphincter volume, bladder and proximal urethral funneling, pubo-urethral ligament integrity, distance of the bladder neck below the pubococcygeal line, posterior urethra-vesical angle, and bladder neck to levator ani distance. US parameters included sling distance to the urethral lumen and pubis, sling position, bladder neck mobility, and lateral arm asymmetry, twisting, or curling. Urodynamic parameters included detrusor overactivity, Valsalva leak point pressure, maximum urethral closure pressure, and bladder outlet obstruction. Important patient parameters included body mass index, age, and previous interventions. CONCLUSIONS Identifying and quantifying causative factors in patients with recurrent SUI, that allow clinicians to modify subsequent treatment choices and techniques may help reduce treatment failure and complications. Formulating algorithms is the next step in optimizing patient counseling, surgical selection, and healthcare allocation.
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Affiliation(s)
- Jeremy Ockrim
- University College London Hospital NHS Trust, University College London, London, UK
| | - Rohna Kearney
- Warrell Unit, Saint Mary's Hospital, Manchester University NHS Trust, UK
- Division of Developmental Biology & Medicine, School of Medical Sciences, University of Manchester, Manchester, UK
| | | | | | | | - Christopher Chermansky
- UPMC Magee Women's Hospital, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - Alan Wein
- Desai Sethi Institute of Urology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Paul Abrams
- Division of Developmental Biology & Medicine, School of Medical Sciences, University of Manchester, Manchester, UK
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Zhao S, Fang M, Li Y, Wang F, Li H, Wang L. Fabrication and in vitro investigation of hyperbranched poly-lysine-grafted warp knitted polypropylene sling for potential treatment of stress urinary incontinence. Biomater Sci 2023; 11:6504-6523. [PMID: 37577866 DOI: 10.1039/d3bm00943b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Polypropylene (PP) sling implantation is the most commonly performed procedure for women with stress urinary incontinence (SUI). However, concerns have arisen regarding complications caused by slings, including the common issue of erosion, which can be attributed to various factors such as the body's response and bacterial contamination. To address these concerns, we have developed a rectangular mesh self-locking edge sling with a large pore size and lightweight design. Promising results have been obtained from preliminary in vivo mechanical reliability tests, including uniaxial tensile tests. In comparative in vitro fixed load tensile tests and simulated Tension-free Vaginal Tape (TVT) and Transobturator Vaginal Tape inside-out (TVT-O) technique tests using commercial slings, our sling demonstrated less transverse wrinkling. Both slings achieved an effective porosity of over 45% under the TVT technique. However, the commercial sling experienced a significant reduction in effective porosity during the TVT-O technique, whereas our sling maintained a stable effective porosity with minimal wrinkling. Furthermore, we successfully developed cationic hydration rejection-driven antibacterial-anti-fouling coatings on the surface of our sling by grafting hyperbranched poly-lysine (HBPL) mediated by polynorepinephrine. The HBPL coating imparts a positive charge and hydrophilicity to the sling, resulting in elevated bactericidal activity and reducing protein adhesion. An optimal grafting concentration of 20 mg mL-1 was selected, confirming the stability and biocompatibility of the sling coating. This coating is expected to reduce the likelihood of postoperative erosion. Overall, our research represents significant advancements in improving the safety and performance of PP slings for stress urinary incontinence, potentially leading to a reduction in complications following surgery.
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Affiliation(s)
- Shuying Zhao
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, China.
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, China
| | - Meiqi Fang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, China.
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, China
| | - Yan Li
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, China.
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, China
| | - Fujun Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, China.
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, China
| | - Hao Li
- Shanghai Hongyu Medical Technology Co., Ltd, Shanghai, China
| | - Lu Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai, China.
- Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai, China
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Liu Z, Tang Y, Liu J, Shi R, Houston M, Munoz A, Zhang Y, Li X. Platelet-rich Plasma Promotes Restoration of the Anterior Vaginal Wall for the Treatment of Pelvic Floor Dysfunction in Rats. J Minim Invasive Gynecol 2023; 30:45-51. [PMID: 36265834 DOI: 10.1016/j.jmig.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 10/11/2022] [Accepted: 10/11/2022] [Indexed: 11/18/2022]
Abstract
STUDY OBJECTIVE To determine the efficacy of using platelet-rich plasma (PRP) for vaginal wall repair in rats with vaginal wall impairment induced by vaginal distension (VD). DESIGN A single-blind, randomized study. SETTING A certified animal research facility. ANIMALS Twenty-four female Sprague Dawley rats. INTERVENTIONS Female Sprague Dawley rats were divided into sham (n = 8), VD (n = 8), and VD + PRP (n = 8) groups. Vaginal tissues from the VD group were dissected at 28-day post injury. VD + PRP rats received vaginal PRP injections on the 1st, 7th, 14th, and 21st day after VD and sacrificed on the 28th day. MEASUREMENTS AND MAIN RESULTS Urodynamic tests were performed in all rats. Immunohistochemistry was used to evaluate matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9). Masson's staining was used to evaluate collagen fibers and calculate collagen volume fraction. Collagen fiber damage was confirmed in the VD group, evidenced by thinner and sparse distribution of collagen fibers, with significantly higher MMP-2 and MMP-9 expression than the sham group (p <.05). The collagen fiber damage in the vaginal wall likely led to pelvic floor dysfunction (PFD), evidenced by significantly decreased bladder leak-point pressure (p <.01) and abdominal leak-point pressure (p <.01) in the VD group compared with the sham group. After completion of the PRP treatment, a significantly higher collagen volume fraction (p <.01) and significantly increased bladder leak-point pressure (p <.05) and abdominal leak-point pressure (p <.01) were achieved in the VD + PRP compared with the VD group, thus indicating repair of the vaginal wall and improvement of PFD. CONCLUSION PRP injections facilitate the regeneration of vaginal wall tissue, particularly collagen fiber, after VD, leading to functional improvement of PFD. Findings support the feasibility of using PRP as a novel treatment for PFD.
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Affiliation(s)
- Zhaoxue Liu
- Department of Rehabilitation Medicine, The Third Xiangya Hospital, Central South University (MM. Liu, Drs. Tang, Liu, Shi, and Li), Changsha
| | - Yuan Tang
- Department of Rehabilitation Medicine, The Third Xiangya Hospital, Central South University (MM. Liu, Drs. Tang, Liu, Shi, and Li), Changsha; Department of Rehabilitation Medicine, The First People's Hospital of Changde City, Changde (Dr. Tang), China
| | - Jiaojiao Liu
- Department of Rehabilitation Medicine, The Third Xiangya Hospital, Central South University (MM. Liu, Drs. Tang, Liu, Shi, and Li), Changsha; Pelvic Floor and Postpartum Rehabilitation Center, Hospital for Maternal and Child Health Care (Dr. Liu), Changsha
| | - Ruting Shi
- Department of Rehabilitation Medicine, The Third Xiangya Hospital, Central South University (MM. Liu, Drs. Tang, Liu, Shi, and Li), Changsha
| | - Michael Houston
- Department of Biomedical Engineering, University of Houston, Houston, (MS. Houston and Dr. Zhang), Texas
| | - Alvaro Munoz
- Centro Universitario del Norte, Universidad de Guadalajara, Colotlán, (Dr. Munoz), Jalisco, Mexico
| | - Yingchun Zhang
- Department of Biomedical Engineering, University of Houston, Houston, (MS. Houston and Dr. Zhang), Texas
| | - Xuhong Li
- Department of Rehabilitation Medicine, The Third Xiangya Hospital, Central South University (MM. Liu, Drs. Tang, Liu, Shi, and Li), Changsha.
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Routzong MR, Martin LC, Rostaminia G, Abramowitch S. Urethral support in female urinary continence part 2: a computational, biomechanical analysis of Valsalva. Int Urogynecol J 2022; 33:551-561. [PMID: 33787951 DOI: 10.1007/s00192-021-04694-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/10/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION AND HYPOTHESIS In Part 1, we observed urethral mechanics during Valsalva that oppose current continence theories. In this study, we utilize a finite element model to elucidate the role of supportive tissues on the urethra during Valsalva. By determining the sensitivity of urethral motion and deformations to variations in tissue stiffnesses, we formulate new hypotheses regarding mechanisms of urethral passive closure. METHODS Anatomy was segmented from a nulliparous, continent woman at rest. The model was tuned such that urethral motion during Valsalva matched that observed in that patient. Urethra and surrounding tissue material properties were varied using Latin hypercube sampling to perform a sensitivity analysis. As in Part 1, urethral length, proximal and distal swinging, and shape parameters were measured at peak Valsalva for 50 simulations, and partial rank correlation coefficients were calculated between all model inputs and outputs. Cumulative influence factors determined which tissue properties were meaningfully influential (≥ 0.5). RESULTS The material properties of the urethra, perineal membrane, bladder, and paraurethral connective tissues meaningfully influenced urethral motion, deformation, and shape. Reduction of the urethral stiffness and/or the perineal membrane soft constraint resulted in simulated urethral motions and shapes associated with stress urinary incontinence in Part 1. CONCLUSIONS The data from Parts 1 and 2 suggest that connective tissues guide the controlled swinging motion and deformation of the urethra needed for passive closure during Valsalva. The swinging and kinking quantified in Part 1 and simulated in Part 2 are inconsistent with current continence theories.
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Affiliation(s)
- Megan R Routzong
- Department of Bioengineering, University of Pittsburgh, 300 O'Hara Street, 406 Benedum Hall, Pittsburgh, PA, 15260, USA
| | - Liam C Martin
- Department of Bioengineering, University of Pittsburgh, 300 O'Hara Street, 406 Benedum Hall, Pittsburgh, PA, 15260, USA
| | - Ghazaleh Rostaminia
- Female Pelvic Medicine and Reconstructive Surgery (FPMRS), Division of Urogynecology, University of Chicago Pritzker School of Medicine, NorthShore University HealthSystem, Skokie, IL, USA
| | - Steven Abramowitch
- Department of Bioengineering, University of Pittsburgh, 300 O'Hara Street, 406 Benedum Hall, Pittsburgh, PA, 15260, USA.
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Treatment with platelet-rich plasma attenuates proprioceptor abnormalities in a rat model of postpartum stress urinary incontinence. Int Urogynecol J 2022; 33:2159-2167. [PMID: 35195739 DOI: 10.1007/s00192-022-05112-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 01/27/2022] [Indexed: 12/23/2022]
Abstract
INTRODUCTION AND HYPOTHESIS Stress urinary incontinence (SUI) is the most prevalent form of urinary incontinence, and vaginal delivery is a major risk factor for developing SUI. We evaluated the hypothesis that applying the autologous platelet rich plasma (PRP) to the pelvic floor muscles via injection affects expression of proprioceptors and improves postpartum stress urinary incontinence (PSUI) in rats. METHODS Virgin female Sprague-Dawley rats were divided into control (n = 10) and experimental group(n = 20). Vaginal dilation was used to establish PSUI, and the rats in the experimental group were further divided into the PSUI group (n = 10) and PSUI+PRP group (n = 10). Pelvic floor muscles from rats in the PSUI+PRP group were positioned under ultrasound guidance for PRP injection. The morphology and number of pelvic floor muscle spindles were assessed using H&E staining, proprioceptors evaluated by gold chloride staining, and changes in the expression of neurotrophin-3 (NT-3) and skeletal myosin MY-32 determined by immunohistochemistry. RESULTS After 28 days,bladder leak point pressure (BLPP) and abdominal leaking-urine point pressure (ALPP) in rats with PSUI were significantly lower than in control animals (P<0.01). Both BLPP and ALPP increased significantly in the PSUI+PRP group (P<0.01). Compared with the control group, muscle spindle morphology and structure in the PSUI and PSUI+PRP groups had different pathological changes,with higher variations in the PSUI group. The positive signals for NT-3/MY-32 expression in control rats were higher than those from PSUI or PSUI+PRP groups, however, the expression for NT-3/MY-32 in PSUI+PRP animals was higher than that seen in the PSUI group (P < 0.01). CONCLUSIONS PSUI rats have an abnormal expression of pelvic proprioceptors, which affect proprioceptive function, and further the contractibility of pelvic floor muscles. A PRP injection may restore the sensory function of pelvic proprioceptors, thus improving urine leakage in PSUI rats.
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Contemporary Review of MRI in Benign Genitourinary Pelvic Medicine: What Every Urologist Should Know. CURRENT BLADDER DYSFUNCTION REPORTS 2021. [DOI: 10.1007/s11884-021-00631-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Lian PH, Ji ZG, Li HZ, Xiao H, Yan WG, Huang ZM. Intraoperative Vaginal Perforation During Various Mid-Urethral Sling Procedures Treating Female Stress Urinary Incontinence. J INVEST SURG 2018; 33:203-210. [PMID: 30461324 DOI: 10.1080/08941939.2018.1492649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Incidence of intraoperative vaginal perforation is generally considered to be low but varies among different procedures. Vaginal perforation could not only prolong the surgeries and aggravate surgical trauma but also result in postoperative discomfort or even a second surgery. METHOD Vaginal perforation, vaginal epithelial perforation, vaginal wall perforation, vaginal penetration, urinary incontinence were searched in PubMed, Cochrane, Embase database to identify the qualified clinical trial and relevant literature sources were also searched. RESULTS A total of 9223 cases of from 33 trials from literatures and 387 cases from our own trail were analyzed, which provided detailed data on intraoperative vaginal perforation. Incidence of intraoperative vaginal perforation during mid-urethral sling surgery treating stress urinary incontinence was generally low, which was 1.56%. Incidence of intraoperative vaginal perforation during transobturator (TOR) procedure was higher than that during retropubic (RPR) procedure, which were 2.11% and 0.89% respectively. Incidence of intraoperative vaginal perforation during outside-to-inside TOR procedure like TOT and MONARC was higher than that during inside-to-outside TOR procedure like TVT-O, which were 2.74% and 1.52%, respectively. Incidence of intraoperative vaginal perforation during single-incision surgery like H-type TVT-SECUR reached 1.97%, while no report on U-type TVT-SECUR surgeries. CONCLUSION The incidence of intraoperative vaginal during mid-urethral sling procedures for female stress urinary incontinence is fairly high. Vaginal perforation was more common in trans-obturator route (TOR) than retropubic route (RPR). In TOR route, it was less frequent in inside-to-outside procedure than outside-to-inside procedure. Surgery proficiency could also have an impact on this complication.
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Affiliation(s)
- Peng-Hu Lian
- Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Zhi-Gang Ji
- Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Han-Zhong Li
- Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - He Xiao
- Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Wei-Gang Yan
- Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Zhong-Ming Huang
- Department of Urology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
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Silva M, Parente M, Brandão S, Mascarenhas T, Natal Jorge R. Characterization of the passive and active material parameters of the pubovisceralis muscle using an inverse numerical method. J Biomech 2018; 71:100-110. [DOI: 10.1016/j.jbiomech.2018.01.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 12/11/2017] [Accepted: 01/28/2018] [Indexed: 12/28/2022]
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Peng Y, Miller BD, Boone TB, Zhang Y. Modern Theories of Pelvic Floor Support : A Topical Review of Modern Studies on Structural and Functional Pelvic Floor Support from Medical Imaging, Computational Modeling, and Electromyographic Perspectives. Curr Urol Rep 2018; 19:9. [PMID: 29435856 DOI: 10.1007/s11934-018-0752-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE OF REVIEW Weakened pelvic floor support is believed to be the main cause of various pelvic floor disorders. Modern theories of pelvic floor support stress on the structural and functional integrity of multiple structures and their interplay to maintain normal pelvic floor functions. Connective tissues provide passive pelvic floor support while pelvic floor muscles provide active support through voluntary contraction. Advanced modern medical technologies allow us to comprehensively and thoroughly evaluate the interaction of supporting structures and assess both active and passive support functions. The pathophysiology of various pelvic floor disorders associated with pelvic floor weakness is now under scrutiny from the combination of (1) morphological, (2) dynamic (through computational modeling), and (3) neurophysiological perspectives. This topical review aims to update newly emerged studies assessing pelvic floor support function among these three categories. RECENT FINDINGS A literature search was performed with emphasis on (1) medical imaging studies that assess pelvic floor muscle architecture, (2) subject-specific computational modeling studies that address new topics such as modeling muscle contractions, and (3) pelvic floor neurophysiology studies that report novel devices or findings such as high-density surface electromyography techniques. We found that recent computational modeling studies are featured with more realistic soft tissue constitutive models (e.g., active muscle contraction) as well as an increasing interest in simulating surgical interventions (e.g., artificial sphincter). Diffusion tensor imaging provides a useful non-invasive tool to characterize pelvic floor muscles at the microstructural level, which can be potentially used to improve the accuracy of the simulation of muscle contraction. Studies using high-density surface electromyography anal and vaginal probes on large patient cohorts have been recently reported. Influences of vaginal delivery on the distribution of innervation zones of pelvic floor muscles are clarified, providing useful guidance for a better protection of women during delivery. We are now in a period of transition to advanced diagnostic and predictive pelvic floor medicine. Our findings highlight the application of diffusion tensor imaging, computational models with consideration of active pelvic floor muscle contraction, high-density surface electromyography, and their potential integration, as tools to push the boundary of our knowledge in pelvic floor support and better shape current clinical practice.
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Affiliation(s)
- Yun Peng
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX, 77004, USA
| | - Brandi D Miller
- Department of Urology, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Timothy B Boone
- Department of Urology, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Yingchun Zhang
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX, 77004, USA.
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Brandão S, Parente M, Da Roza TH, Silva E, Ramos IM, Mascarenhas T, Natal Jorge RM. On the Stiffness of the Mesh and Urethral Mobility: A Finite Element Analysis. J Biomech Eng 2017; 139:2625659. [DOI: 10.1115/1.4036606] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Indexed: 12/13/2022]
Abstract
Midurethral slings are used to correct urethral hypermobility in female stress urinary incontinence (SUI), defined as the complaint of involuntary urine leakage when the intra-abdominal pressure (IAP) is increased. Structural and thermal features influence their mechanical properties, which may explain postoperative complications, e.g., erosion and urethral obstruction. We studied the effect of the mesh stiffness on urethral mobility at Valsalva maneuver, under impairment of the supporting structures (levator ani and/or ligaments), by using a numerical model. For that purpose, we modeled a sling with “lower” versus “higher” stiffness and evaluated the mobility of the bladder and urethra, that of the urethrovesical junction (the α-angle), and the force exerted at the fixation of the sling. The effect of impaired levator ani or pubourethral ligaments (PUL) alone on the organs displacement and α-angle opening was similar, showing their important role together on urethral stabilization. When the levator ani and all the ligaments were simulated as impaired, the descent of the bladder and urethra went up to 25.02 mm, that of the bladder neck was 14.57 mm, and the α-angle was 129.7 deg, in the range of what was found in women with SUI. Both meshes allowed returning to normal positioning, although at the cost of higher force exerted by the mesh with higher stiffness (3.4 N against 2.3 N), which can relate to tissue erosion. This finite element analysis allowed mimicking the biomechanical response of the pelvic structures in response to changing a material property of the midurethral synthetic mesh.
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Affiliation(s)
- Sofia Brandão
- Department of Radiology, Centro Hospitalar de São João—EPE (CHSJ-EPE)/Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto 4200-319, Portugal
- Associated Laboratory for Energy, Transports and Aeronautics (LAETA), Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal e-mail:
| | - Marco Parente
- Associated Laboratory for Energy, Transports and Aeronautics (LAETA), Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal e-mail:
| | - Thuane Huyer Da Roza
- Biomechanics Laboratory, Center of Health and Sport Sciences, Santa Catarina State University (CEFID/UDESC), Rua Paschoal Simone, 358, Bairro dos Coqueiros, Florianópolis 88080-350, Santa Catarina, Brazil
- Associated Laboratory for Energy, Transports and Aeronautics (LAETA), Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal e-mail:
| | - Elisabete Silva
- Associated Laboratory for Energy, Transports and Aeronautics (LAETA), Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal e-mail:
| | - Isabel Maria Ramos
- Department of Radiology, CHSJ-EPE/Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto 4200-319, Portugal e-mail:
| | - Teresa Mascarenhas
- Department of Obstetrics and Gynecology, CHSJ-EPE/Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto 4200-319, Portugal e-mail:
| | - Renato Manuel Natal Jorge
- Associated Laboratory for Energy, Transports and Aeronautics (LAETA), Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, Porto 4200-465, Portugal e-mail:
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HE JINBAO, YI XINHUA, LUO ZAIFEI. CHARACTERIZATION OF MOTOR UNIT AT DIFFERENT STRENGTHS WITH MULTI-CHANNEL SURFACE ELECTROMYOGRAPHY. J MECH MED BIOL 2017. [DOI: 10.1142/s0219519417500245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this study, specific changes in electromyographic characteristics of individual motor units (MUs) associated with different muscle contraction forces are investigated using multi-channel surface electromyography (SEMG). The gradient convolution kernel compensation (GCKC) algorithm is employed to separate individual MUs from their surface interferential electromyography (EMG) signals and provide the discharge instants, which is later used in the spike-triggered averaging (STA) techniques to obtain the complete waveform. The method was tested on experimental SEMG signals acquired during constant force contractions of biceps brachii muscles in five subjects. Electromyographic characteristics including the recruitment number, waveform amplitude, discharge pattern and innervation zone (IZ) are studied. Results show that changes in the action potential of single MU with different contraction force levels are consistent with those for all MUs, and that the amplitude of MU action potentials (MUAPs) provides a useful estimate of the muscle contraction forces.
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Affiliation(s)
- JINBAO HE
- School of Electronic and Information, Ningbo University of Science, Ningbo, Zhejiang, P. R. China
| | - XINHUA YI
- School of Mechanical Engineering, Ningbo University of Science, Ningbo, Zhejiang, P. R. China
| | - ZAIFEI LUO
- School of Electronic and Information, Ningbo University of Science, Ningbo, Zhejiang, P. R. China
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Dias N, Peng Y, Khavari R, Nakib NA, Sweet RM, Timm GW, Erdman AG, Boone TB, Zhang Y. Pelvic floor dynamics during high-impact athletic activities: A computational modeling study. Clin Biomech (Bristol, Avon) 2017; 41:20-27. [PMID: 27886590 PMCID: PMC5519824 DOI: 10.1016/j.clinbiomech.2016.11.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 11/09/2016] [Accepted: 11/15/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Stress urinary incontinence is a significant problem in young female athletes, but the pathophysiology remains unclear because of the limited knowledge of the pelvic floor support function and limited capability of currently available assessment tools. The aim of our study is to develop an advanced computer modeling tool to better understand the dynamics of the internal pelvic floor during highly transient athletic activities. METHODS Apelvic model was developed based on high-resolution MRI scans of a healthy nulliparous young female. A jump-landing process was simulated using realistic boundary conditions captured from jumping experiments. Hypothesized alterations of the function of pelvic floor muscles were simulated by weakening or strengthening the levator ani muscle stiffness at different levels. Intra-abdominal pressures and corresponding deformations of pelvic floor structures were monitored at different levels of weakness or enhancement. FINDINGS Results show that pelvic floor deformations generated during a jump-landing process differed greatly from those seen in a Valsalva maneuver which is commonly used for diagnosis in clinic. The urethral mobility was only slightly influenced by the alterations of the levator ani muscle stiffness. Implications for risk factors and treatment strategies were also discussed. INTERPRETATION Results suggest that clinical diagnosis should make allowances for observed differences in pelvic floor deformations between a Valsalva maneuver and a jump-landing process to ensure accuracy. Urethral hypermobility may be a less contributing factor than the intrinsic sphincteric closure system to the incontinence of young female athletes.
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Affiliation(s)
- Nicholas Dias
- Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA.
| | - Yun Peng
- Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA.
| | - Rose Khavari
- Department of Urology, Houston Methodist Hospital and Research Institute, 6565 Fannin St, Suite 2100, Houston, TX 77030-2703, USA.
| | - Nissrine A Nakib
- Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA.
| | - Robert M Sweet
- Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA.
| | - Gerald W Timm
- Department of Urology, University of Minnesota, 420 Delaware St. SE MMC 394, Minneapolis, MN 55455-0341, USA.
| | - Arthur G Erdman
- Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455-0341, USA.
| | - Timothy B Boone
- Department of Urology, Houston Methodist Hospital and Research Institute, 6565 Fannin St, Suite 2100, Houston, TX 77030-2703, USA.
| | - Yingchun Zhang
- Department of Biomedical Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX 77004, USA.
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13
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Peng Y, He J, Khavari R, Boone TB, Zhang Y. Functional mapping of the pelvic floor and sphincter muscles from high-density surface EMG recordings. Int Urogynecol J 2016; 27:1689-1696. [PMID: 27193113 PMCID: PMC5519819 DOI: 10.1007/s00192-016-3026-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 04/11/2016] [Indexed: 12/17/2022]
Abstract
INTRODUCTION AND HYPOTHESIS Knowledge of the innervation of pelvic floor and sphincter muscles is of great importance to understanding the pathophysiology of female pelvic floor dysfunctions. This report presents our high-density intravaginal and intrarectal electromyography (EMG) probes and a comprehensive innervation zone (IZ) imaging technique based on high-density EMG readings to characterize the IZ distribution. METHODS Both intravaginal and intrarectal probes are covered with a high-density surface electromyography electrode grid (8 × 8). Surface EMG signals were acquired in ten healthy women performing maximum voluntary contractions of their pelvic floor. EMG decomposition was performed to separate motor-unit action potentials (MUAPs) and then localize their IZs. RESULTS High-density surface EMG signals were successfully acquired over the vaginal and rectal surfaces. The propagation patterns of muscle activity were clearly visualized for multiple muscle groups of the pelvic floor and anal sphincter. During each contraction, up to 218 and 456 repetitions of motor units were detected by the vaginal and rectal probes, respectively. MUAPs were separated with their IZs identified at various orientations and depths. CONCLUSIONS The proposed probes are capable of providing a comprehensive mapping of IZs of the pelvic floor and sphincter muscles. They can be employed as diagnostic and preventative tools in clinical practices.
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Affiliation(s)
- Yun Peng
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX, 77004, USA
| | - Jinbao He
- School of Electronic and Information Engineering, Ningbo University of Technology, Ningbo, China
| | - Rose Khavari
- Department of Urology, Houston Methodist Hospital and Research Institute, Houston, TX, 77030, USA
| | - Timothy B Boone
- Department of Urology, Houston Methodist Hospital and Research Institute, Houston, TX, 77030, USA
| | - Yingchun Zhang
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, 360 HBS Building, 4811 Calhoun Rd., Houston, TX, 77004, USA.
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14
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Natali AN, Carniel EL, Frigo A, Pavan PG, Todros S, Pachera P, Fontanella CG, Rubini A, Cavicchioli L, Avital Y, De Benedictis GM. Experimental investigation of the biomechanics of urethral tissues and structures. Exp Physiol 2016; 101:641-56. [PMID: 26864993 DOI: 10.1113/ep085476] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 02/04/2016] [Indexed: 12/20/2022]
Abstract
NEW FINDINGS What is the central question of this study? Prostheses for treatment of urinary incontinence elicit complications associated with an inadequate mechanical action. This investigation aimed to define a procedure addressed to urethral mechanical characterization. Experimental tests are the basis for constitutive formulation, with a view to numerical modelling for investigation of the interaction between the tissues and a prosthesis. What is the main finding and its importance? Horse urethra, selected for its histomorphometric similarity to human urethra, was characterized by integrated histological analysis and mechanical tests on the biological tissue and structure, leading to constitutive formulation. A non-linear, anisotropic and time-dependent response was found, representing a valid basis for development of a numerical model to interpret the functional behaviour of the urethra. Urinary dysfunction can lead to incontinence, with an impact on the quality of life. Severe dysfunction can be overcome surgically by the use of an artificial urinary sphincter. Nonetheless, several complications may result from inappropriate functioning of the prosthesis, in many instances resulting from an unsuitable mechanical action of the device on the urethral tissues. Computational models allow investigation of the mechanical interaction between biological tissues and biomedical devices, representing a potential support for surgical practice and prosthesis design. The development of such computational tools requires experimental data on the mechanics of biological tissues and structures, which are rarely reported in the literature. The aim of this study was to provide a procedure for the mechanical characterization of urethral tissues and structures. The experimental protocol included the morphometric and histological analysis of urethral tissues, the mechanical characterization of the response of tissues to tensile and stress-relaxation tests and evaluation of the behaviour of urethral structures by inflation tests. Results from the preliminary experiments were processed, adopting specific model formulations, and also providing the definition of parameters that characterize the elastic and viscous behaviour of the tissues. Different experimental protocols, leading to a comprehensive set of experimental data, allow for a reciprocal assessment of reliability of the investigation approach.
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Affiliation(s)
- Arturo Nicola Natali
- Department of Industrial Engineering, University of Padova, Italy.,Centre for Mechanics of Biological Materials, University of Padova, Italy
| | - Emanuele Luigi Carniel
- Department of Industrial Engineering, University of Padova, Italy.,Centre for Mechanics of Biological Materials, University of Padova, Italy
| | - Alessandro Frigo
- Department of Industrial Engineering, University of Padova, Italy.,Centre for Mechanics of Biological Materials, University of Padova, Italy
| | - Piero Giovanni Pavan
- Department of Industrial Engineering, University of Padova, Italy.,Centre for Mechanics of Biological Materials, University of Padova, Italy
| | - Silvia Todros
- Department of Industrial Engineering, University of Padova, Italy.,Centre for Mechanics of Biological Materials, University of Padova, Italy
| | - Paola Pachera
- Department of Industrial Engineering, University of Padova, Italy.,Centre for Mechanics of Biological Materials, University of Padova, Italy
| | - Chiara Giulia Fontanella
- Centre for Mechanics of Biological Materials, University of Padova, Italy.,Department of Biomedical Sciences, University of Padova, Italy
| | - Alessandro Rubini
- Centre for Mechanics of Biological Materials, University of Padova, Italy.,Department of Biomedical Sciences, University of Padova, Italy
| | - Laura Cavicchioli
- Department of Comparative Biomedicine and Food Science, University of Padova, Italy
| | - Yochai Avital
- Department of Animal Medicine, Production and Health, University of Padova, Italy
| | - Giulia Maria De Benedictis
- Centre for Mechanics of Biological Materials, University of Padova, Italy.,Department of Animal Medicine, Production and Health, University of Padova, Italy
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15
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Di Biase M, Malhorta N, Kocjancic E. Management of stress urinary incontinence. SEMINARS IN COLON AND RECTAL SURGERY 2016. [DOI: 10.1053/j.scrs.2015.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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16
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Peng Y, Khavari R, Nakib NA, Boone TB, Zhang Y. Assessment of urethral support using MRI-derived computational modeling of the female pelvis. Int Urogynecol J 2016; 27:205-12. [PMID: 26224383 PMCID: PMC5519823 DOI: 10.1007/s00192-015-2804-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 07/13/2015] [Indexed: 01/03/2023]
Abstract
INTRODUCTION AND HYPOTHESIS This study aimed to assess the role of individual anatomical structures and their combinations to urethral support function. METHODS A realistic pelvic model was developed from an asymptomatic female patient's magnetic resonance (MR) images for dynamic biomechanical analysis using the finite element method. Validation was performed by comparing simulation results with dynamic MR imaging observations. Weaknesses of anatomical support structures were simulated by reducing their material stiffness. Urethral mobility was quantified by examining urethral axis excursion from rest to the final state (intra-abdominal pressure = 100 cmH2O). Seven individual support structures and five of their combinations were studied. RESULT Among seven urethral support structures, we found that weakening the vaginal walls, puborectalis muscle, and pubococcygeus muscle generated the top three largest urethral excursion angles. A linear relationship was found between urethral axis excursions and intra-abdominal pressure. Weakening all three levator ani components together caused a larger weakening effect than the sum of each individually weakened component, indicating a nonlinearly additive pattern. The pelvic floor responded to different weakening conditions distinctly: weakening the vaginal wall developed urethral mobility through the collapsed vaginal canal, while weakening the levator ani showed a more uniform pelvic floor deformation. CONCLUSIONS The computational modeling and dynamic biomechanical analysis provides a powerful tool to better understand the dynamics of the female pelvis under pressure events. The vaginal walls, puborectalis, and pubococcygeus are the most important individual structures in providing urethral support. The levator ani muscle group provides urethral support in a well-coordinated way with a nonlinearly additive pattern.
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Affiliation(s)
- Yun Peng
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, 2027 SERC Building, 3605 Cullen Blvd, Houston, TX, 77024, USA
| | - Rose Khavari
- Department of Urology, Houston Methodist Hospital and Research Institute, Houston, TX, 77030, USA
| | - Nissrine A Nakib
- Department of Urology, University of Minnesota, Minneapolis, MN, USA
| | - Timothy B Boone
- Department of Urology, Houston Methodist Hospital and Research Institute, Houston, TX, 77030, USA
| | - Yingchun Zhang
- Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, 2027 SERC Building, 3605 Cullen Blvd, Houston, TX, 77024, USA.
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17
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Todros S, Pavan PG, Natali AN. Biomechanical properties of synthetic surgical meshes for pelvic prolapse repair. J Mech Behav Biomed Mater 2015; 55:271-285. [PMID: 26615384 DOI: 10.1016/j.jmbbm.2015.10.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/26/2015] [Accepted: 10/27/2015] [Indexed: 12/27/2022]
Abstract
Synthetic meshes are widely used for surgical repair of different kind of prolapses. In the light of the experience of abdominal wall repair, similar prostheses are currently used in the pelvic region, to restore physiological anatomy after organ prolapse into the vaginal wall, that represent a recurrent dysfunction. For this purpose, synthetic meshes are surgically positioned in contact with the anterior and/or posterior vaginal wall, to inferiorly support prolapsed organs. Nonetheless, while mesh implantation restores physiological anatomy, it is often associated with different complications in the vaginal region. These potentially dangerous effects induce the surgical community to reconsider the safety and efficacy of mesh transvaginal placement. For this purpose, the evaluation of state-of-the-art research may provide the basis for a comprehensive analysis of mesh compatibility and functionality. The aim of this work is to review synthetic surgical meshes for pelvic organs prolapse repair, taking into account the mechanics of mesh material and structure, and to relate them with pelvic and vaginal tissue biomechanics. Synthetic meshes are currently available in different chemical composition, fiber and textile conformations. Material and structural properties are key factors in determining mesh biochemical and mechanical compatibility in vivo. The most significant results on vaginal tissue and surgical meshes mechanical characterization are here reported and discussed. Moreover, computational models of the pelvic region, which could support the surgeon in the evaluation of mesh performances in physiological conditions, are recalled.
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Affiliation(s)
- S Todros
- Department of Industrial Engineering, Centre for Mechanics of Biological Materials, University of Padova, via Marzolo 9, I-35131 Padova, Italy.
| | - P G Pavan
- Department of Industrial Engineering, Centre for Mechanics of Biological Materials, University of Padova, via Marzolo 9, I-35131 Padova, Italy
| | - A N Natali
- Department of Industrial Engineering, Centre for Mechanics of Biological Materials, University of Padova, via Marzolo 9, I-35131 Padova, Italy
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18
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Peng Y, Dai Z, Mansy HA, Henry BM, Sandler RH, Balk RA, Royston TJ. Sound transmission in porcine thorax through airway insonification. Med Biol Eng Comput 2015; 54:675-89. [PMID: 26280512 DOI: 10.1007/s11517-015-1358-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 07/14/2015] [Indexed: 01/26/2023]
Abstract
Many pulmonary injuries and pathologies may lead to structural and functional changes in the lungs resulting in measurable sound transmission changes on the chest surface. Additionally, noninvasive imaging of externally driven mechanical wave motion in the chest (e.g., using magnetic resonance elastography) can provide information about lung structural property changes and, hence, may be of diagnostic value. In the present study, a comprehensive computational simulation (in silico) model was developed to simulate sound wave propagation in the airways, lung, and chest wall under normal and pneumothorax conditions. Experiments were carried out to validate the model. Here, sound waves with frequency content from 50 to 700 Hz were introduced into airways of five porcine subjects via an endotracheal tube, and transmitted waves were measured by scanning laser Doppler vibrometry at the chest wall surface. The computational model predictions of decreased sound transmission with pneumothorax were consistent with experimental measurements. The in silico model can also be used to visualize wave propagation inside and on the chest wall surface for other pulmonary pathologies, which may help in developing and interpreting diagnostic procedures that utilize sound and vibration.
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Affiliation(s)
- Ying Peng
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St, 2039 ERF, Chicago, IL, 60607, USA.
| | - Zoujun Dai
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St, 2039 ERF, Chicago, IL, 60607, USA
| | - Hansen A Mansy
- University of Central Florida, Orlando, FL, 32816, USA.,Nemours Children's Hospital, Orlando, FL, 32827, USA
| | - Brian M Henry
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St, 2039 ERF, Chicago, IL, 60607, USA
| | - Richard H Sandler
- University of Central Florida, Orlando, FL, 32816, USA.,Nemours Children's Hospital, Orlando, FL, 32827, USA
| | - Robert A Balk
- Rush University Medical Center, Chicago, IL, 60612, USA
| | - Thomas J Royston
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St, 2039 ERF, Chicago, IL, 60607, USA
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