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Biomechanical or mechanical and vagina

Rita Rynkevic, Pedro Martins, Lucie Hympanova, Henrique Almeida, Antonio A Fernandes, Jan Deprest
Pelvic floor soft tissues undergo changes during the pregnancy. However, the degree and nature of this process is not completely characterized. This study investigates the effect of subsequent pregnancy on biomechanical and structural properties of ovine vagina. Vaginal wall from virgin, pregnant (in their third pregnancy) and parous (one year after third vaginal delivery) Swifter sheep (n=5 each) was harvested. Samples for biomechanics and histology, were cut in longitudinal axis (proximal and distal regions)...
May 24, 2017: Journal of Biomechanics
Rui Liang, Katrina Knight, William Barone, Robert W Powers, Alexis Nolfi, Stacy Palcsey, Steven Abramowitch, Pamela A Moalli
BACKGROUND: The use of wide pore lightweight polypropylene mesh to improve anatomical outcomes in the surgical repair of prolapse has been hampered by mesh complications. One of the prototype prolapse meshes has been found to negatively impact the vagina by inducing a decrease in smooth muscle volume and contractility and the degradation of key structural proteins (collagen and elastin), resulting in vaginal degeneration. Recently, bioscaffolds derived from extracellular matrix have been used to mediate tissue regeneration and have been widely adopted in tissue engineering applications...
February 2017: American Journal of Obstetrics and Gynecology
Rui Liang, Katrina Knight, Alexis Nolfi, Steven Abramowitch, Pamela A Moalli
OBJECTIVE: Some selective estrogen receptor modulators (SERMs) have been associated with increased incidence of urinary incontinence and pelvic organ prolapse. This study explored the effects of five SERMs on the function and matrix components of the vagina and its supportive tissues. METHODS: Fifty-six rats were administered SERMs by oral gavage for 8 weeks (n = 8 for each SERM): raloxifene, tamoxifen, idoxifene, bazedoxifene at three different doses, and bazedoxifene with conjugated estrogens...
February 2016: Menopause: the Journal of the North American Menopause Society
Daniela Ulrich, Sharon L Edwards, Vincent Letouzey, Kai Su, Jacinta F White, Anna Rosamilia, Caroline E Gargett, Jerome A Werkmeister
OBJECTIVE: There are increasing numbers of reports describing human vaginal tissue composition in women with and without pelvic organ prolapse with conflicting results. The aim of this study was to compare ovine and human posterior vaginal tissue in terms of histological and biochemical tissue composition and to assess passive biomechanical properties of ovine vagina to further characterise this animal model for pelvic organ prolapse research. STUDY DESIGN: Vaginal tissue was collected from ovariectomised sheep (n = 6) and from postmenopausal women (n = 7) from the proximal, middle and distal thirds...
2014: PloS One
Xuemei Fan, Yanzhou Wang, Yu Wang, Huicheng Xu
INTRODUCTION AND HYPOTHESES: Our aim was to compare histological and biomechanical effects of polypropylene (PP) mesh and porcine-derived, cross-linked urinary bladder matrix (cUBM) graft materials using a rabbit vaginal and abdominal model. METHODS: Forty rabbits were implanted with PP mesh (n = 20) or cUBM (n = 20) in the vagina and abdomen. Two grafts (PP or cUBM) of the same type were placed into each site, so each rabbit had four grafts. Grafts were harvested 12 weeks later and processed for histologic analysis and biomechanical testing...
May 2014: International Urogynecology Journal
Daniela Ulrich, Sharon Lee Edwards, Kai Su, Ker Sin Tan, Jacinta F White, John A M Ramshaw, Camden Lo, Anna Rosamilia, Jerome A Werkmeister, Caroline E Gargett
BACKGROUND: Pelvic organ prolapse (POP) is defined as the descent of one or more of the pelvic structures into the vagina and includes uterine, vaginal vault, and anterior or posterior vaginal wall prolapse. The treatment of POP may include implantation of a synthetic mesh. However, the long-term benefit of mesh surgery is controversial due to complications such as mesh exposure or pain. The aim of this study was to use a tissue engineering (TE) approach to assess the in vivo biological and biomechanical behavior of a new gelatin/polyamide mesh, seeded with a novel source of mesenchymal stem cells in a subcutaneous rat model of wound repair...
February 2014: Tissue Engineering. Part A
Alejandra M Ruiz-Zapata, Manon H Kerkhof, Behrouz Zandieh-Doulabi, Hans A M Brölmann, Theo H Smit, Marco N Helder
INTRODUCTION AND HYPOTHESIS: Little is known about dynamic cell-matrix interactions in the context of pathophysiology and treatments for pelvic organ prolapse (POP). This study sought to identify differences between fibroblasts from women with varying degrees of prolapse in reaction to mechanical stimuli and matrix substrates in vitro. METHODS: Fibroblasts from the vaginal wall of three patients with POP Quantification (POP-Q) system stages 0, II, and IV were stretched on artificial polymer substrates either coated or not coated with collagen I...
September 2013: International Urogynecology Journal
A Feola, S Abramowitch, Z Jallah, S Stein, W Barone, S Palcsey, P Moalli
OBJECTIVE: To define the impact of prolapse mesh on the biomechanical properties of the vagina by comparing the prototype Gynemesh PS (Ethicon) to two new-generation lower stiffness meshes, SmartMesh (Coloplast) and UltraPro (Ethicon). DESIGN: A study employing a nonhuman primate model. SETTING: University of Pittsburgh, PA, USA. POPULATION: Forty-five parous rhesus macaques. METHODS: Meshes were implanted via sacrocolpopexy after hysterectomy and compared with sham...
January 2013: BJOG: An International Journal of Obstetrics and Gynaecology
Andrew Feola, Robert Duerr, Pamela Moalli, Steven Abramowitch
INTRODUCTION AND HYPOTHESIS: Pelvic organ prolapse is a common condition impacting the quality of life of millions of women worldwide. Although vaginal estrogen is widely used in women with prolapse, little is known regarding estrogen's benefits on the biomechanical properties of vaginal tissue. Here, we aimed to examine the effect of prolapse on the biomechanical properties of the vagina and determine alterations in vaginal mechanics in the presence and absence of hormone therapy (HT)...
July 2013: International Urogynecology Journal
Daniela Ulrich, Sharon L Edwards, Jacinta F White, Tommy Supit, John A M Ramshaw, Camden Lo, Anna Rosamilia, Jerome A Werkmeister, Caroline E Gargett
INTRODUCTION: Fascial defects are a common problem in the abdominal wall and in the vagina leading to hernia or pelvic organ prolapse that requires mesh enhancement to reduce operation failure. However, the long-term outcome of synthetic mesh surgery may be unsatisfactory due to post-surgical complications. We hypothesized that mesh fabricated from alternative synthetic polymers may evoke a different tissue response, and provide more appropriate mechanical properties for hernia repair...
2012: PloS One
E Peña, P Martins, T Mascarenhas, R M Natal Jorge, A Ferreira, M Doblaré, B Calvo
The mechanical properties of vaginal tissue need to be characterized to perform accurate simulations of prolapse and other pelvic disorders that commonly affect women. This is also a fundamental step towards the improvement of therapeutic techniques such as surgery. In this paper, the softening behavior or Mullins effect of vaginal tissue is studied by proposing an appropriate constitutive model. This effect is an important factor after the birth, since vaginal tissue has been supporting a high load distribution and therefore does not recover its original behavior...
April 2011: Journal of the Mechanical Behavior of Biomedical Materials
Andrew Feola, Steven Abramowitch, Keisha Jones, Suzan Stein, Pamela Moalli
OBJECTIVE: The purpose of this study was to determine the impact of parity on mechanical behavior of the vagina and to correlate these findings with alterations in collagen structure. STUDY DESIGN: Mechanical properties of 5 nulliparous and 6 parous rhesus macaques were derived from uniaxial tensile tests. Collagen ratios and alignment were quantified by quantitative fluorescent microscopy and picrosirius red staining. Outcomes were compared by the Student t test or Mann Whitney U test (P < ...
December 2010: American Journal of Obstetrics and Gynecology
Karel Jelen, Hynek Herman, Frantisek Lopot, Petr Kubovy, Michal Otcenasek, Radek Sedlacek
OBJECTIVE: This work focuses on finding method for detecting the elementary mechanical characteristics of the vagina-endopelvic fascia complex, aimed at providing results for use in optimizing solutions for stability defects of the pelvic floor. MATERIALS AND METHODS: Two experiments have already been carried out that have enabled monitoring of the reaction of tissue complex samples to a selected load. The elastic properties of samples under a simple pull load were evaluated...
2010: Neuro Endocrinology Letters
Lisa M Pierce, Melissa A Grunlan, Yaping Hou, Shannon S Baumann, Thomas J Kuehl, Tristi W Muir
OBJECTIVE: We sought to evaluate the effects of anatomic location and ovariectomy on biomechanical properties of synthetic and biologic graft materials after long-term implantation. STUDY DESIGN: A total of 35 rabbits underwent ovariectomy or sham laparotomy and were implanted with polypropylene (PP) mesh (n = 17) or cross-linked porcine dermis (PS) (n = 18) in the vagina and abdomen. Grafts were harvested 9 months later and underwent mechanical properties testing...
May 2009: American Journal of Obstetrics and Gynecology
Philippe E Zimmern, Robert C Eberhart, Aradhana Bhatt
GOAL: To explore the methodological challenges of biomechanical testing of freshly harvested human anterior vaginal wall (HAVW) samples. METHOD: Longitudinal full-thickness samples of HAVW were excised during cystocele repair in postmenopausal women and age-matched controls. Two methods of tissue storage during transport were compared. All samples were prepared for uniaxial testing within 2 hr of harvest and loaded at a rate of 0.5 mm/sec, until irreversible deformation was observed...
2009: Neurourology and Urodynamics
Pamela A Moalli, Kristen M Debes, Leslie A Meyn, Nancy S Howden, Steven D Abramowitch
OBJECTIVE: The objective of the study was to determine the impact of hormones on the biomechanical properties of the vagina and its supportive tissues following surgical menopause in young vs middle-aged rats. STUDY DESIGN: Long-Evans rats (4-month virgin [n = 34], 4-month parous [n = 36], and 9-month parous [n = 34]), underwent ovariectomy (OVX) or sham surgery. OVX animals received hormones (estrogen [E2] or estrogen plus progesterone [E2 plus P4]), placebo, or a matrix metalloproteinase inhibitor (chemically modified tetracycline-8 [CMT-8])...
August 2008: American Journal of Obstetrics and Gynecology
Rachelle L Prantil, Ron J Jankowski, Yasuhiro Kaiho, William C de Groat, Michael B Chancellor, Naoki Yoshimura, David A Vorp
Stress urinary incontinence (SUI) is the involuntary release of urine during sudden increases in abdominal pressures. SUI is common in women after vaginal delivery or pelvic trauma and may alter the biomechanical properties of the urethra. Thus we hypothesize that injury due to vaginal distension (VD) decreases urethral basal tone and passive stiffness. This study aimed to assess the biomechanical properties of the urethra after VD in the baseline state, where basal muscle tone and extracellular matrix (ECM) are present, and in the passive state, where inactive muscle and ECM are present...
April 2007: American Journal of Physiology. Renal Physiology
Wesley S Hilger, Andrew Walter, Mark E Zobitz, Kevin O Leslie, Paul Magtibay, Jeffrey Cornella
OBJECTIVE: The objective of the study was to describe the histologic and biomechanical changes of implanted dermal collagen graft materials. STUDY DESIGN: Twenty rabbits were randomized into 2 groups (6 and 12 weeks, respectively). Each rabbit had 4 graft segments (human dermis, porcine dermis, porcine collagen-coated polypropylene mesh, and autologous fascia) randomly implanted into the abdomen and the vagina. Biomechanical testing and histologic analysis was performed after recovery of graft segments...
December 2006: American Journal of Obstetrics and Gynecology
Mohammed El Khwad, Vishal Pandey, Bradley Stetzer, Brian M Mercer, Deepak Kumar, Robert M Moore, Jennifer Fox, Raymond W Redline, Joseph M Mansour, John J Moore
BACKGROUND: Recently we identified a weak zone in term, pre-labor (repeat Cesarean section) human fetal membranes (FM) overlying the cervix with biochemical characteristics suggestive of apoptosis and collagen remodeling. We suggested that this weak zone is the FM rupture initiation site. Vaginally delivered patients have a weak zone in their FM overlying the cervix; a comparable weak zone lies adjacent to the tear line in FM after spontaneous rupture (SROM). METHODS: FM from vaginally delivered patients with artificial rupture (AROM) and SROM were collected...
April 2006: Journal of the Society for Gynecologic Investigation
M Boukerrou, E Lambaudie, P Collinet, S Lacaze, H Mesdagh, A Ego, M Cosson
OBJECTIVE: Underline the objective strength of the pelvic ligaments. PATIENTS AND METHODS: Twenty nine human female pelvis cadavers, whose storage conditions differed, were used in our study. In each cadaver we dissected all the ligaments used in pelvic surgery. A subjective clinical evaluation of the ligament properties was performed by visual observation as well as by finger palpation. Ligaments were classified into three groups in terms of thickness and apparent strength following finger palpation, high, doubtful and low apparent quality ligaments...
July 2004: Gynécologie, Obstétrique & Fertilité
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