Pamela Moalli, MD, PhD

Professor, Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Division of Urogynecology & Pelvic Reconstructive Surgery, UPMC Magee-Womens Hospital


The Center for Interdisciplinary Research in Female Pelvic Health (CIRPH): Co-directed by Pamela Moalli MD PhD and Steve Abramowitch PhD, the overarching goal of this collaboration is to contribute insights into the pathogenesis, diagnosis and treatment of pelvic organ prolapse and urinary incontinence. Their main areas of research focus are 1) the use of biomaterials in urogynecologic procedures (R01061811, R01HD083383, ACELL, DOD11959679) 2) defining mechanisms of failure after reconstructive pelvic surgeries (U01HD069006), 3) defining mechanisms of maternal birth injury (R01HD067627). The group has expertise in cellular and molecular biology including both traditional and high throughput platforms, soft tissue mechanics, mechanobiology, tissue regeneration and immunomodulation. Their current portfolio of investigations include:

Synthetic materials for urogynecologic applications: the group is a world leader in studies defining the impact of commonly used urogynecologic meshes on the vagina (histomorphologic, biochemical and mechanical endpoints) in animal models (primate) and women, modifying the host response to improve long term outcomes, and developing meshes that are designed specifically for the material properties of the vagina (current materials are simply hernia meshes remarketed for prolapse surgery as 510K devices). In ex vivo mechanical tests in conjunction with computational analyses, they have clearly demonstrated that prolapse meshes often have markedly unstable geometries with a dramatic loss of porosity with small applications of tension and that stresses imposed on the vagina by the mesh have significant regional variability. These effects are largely driven by modifiable factors including the pore geometry of the mesh, the degree of tension, and how the mesh is anchored. Indeed, the group’s experimental and computational model predictions of the impact of these mechanical effects are confirmed in mesh explants removed from women with mesh complications which demonstrate buckles, folds, and pore collapse. Using ex vivo mechanical tests in conjunction with animal models and computational analyses, the group previously demonstrated that most mesh used for incontinence and prolapse surgery have unstable geometries with a loss of porosity under modest tension. They hypothesize that this is a mechanism for complications (exposures and visceral erosions). The group is currently developing a new generation of meshes based on elastomeric polymers and stable geometries as an alternative to current polypropylene meshes which plastically deform when loaded. In addition, they are working towards personalized meshes based on 3D modeling of an individual patient’s vagina and specific support defects with the idea that it is unlikely that a single mesh type and geometry is an appropriate match for all women with prolapse.

Selected Publications

  • Moalli PA, Talarico LC, Sung VW, Klingensmith WL, Shand SH, Meyn LA, Watkins SC. Impact of menopause on collagen subtypes in the arcus tendineous fasciae pelvis. Am J Obstet Gynecol. 2004 Mar;190(3):620-7.
  • Moalli PA, Shand SH, Zyczynski HM, Gordy SC, Meyn LA. Remodeling of vaginal connective tissue in patients with prolapse.  Obstet Gynecol. 2005 Nov;106(5 Pt 1):953-63.
  • Moalli PA, Debes KM, Meyn LA, Howden N, Abramowitch SD. Hormones restore biomechanical properties of the vagina and supportive tissues after surgical menopause in young rats.  Am J Obstet Gynecol. 2008 Aug;199(2):161.e1-8. Epub 2008 Apr 8. PMCID: PMC2917050
  • Zong W, Stein S, Meyn L, Starcher B and Moalli PA. Alteration of vaginal elastin metabolism in women with pelvic organ prolapse.  Obstet Gynecol, 2010 May: 115(5) 953-61. PMCID: PMC3042770
  • Alperin M, Feola A, Meyn L, Duerr R, Abramowitch S, Moalli P. Collagen scaffold: a treatment for simulated maternal birth injury in the rat model.   Am J Obstet Gynecol. 2010 Jun; 202(6): 589.e1–589.e8 PMCID: PMC2921182
  • Feola A, Abramowitch S, Jallah Z, Stein S, Barone W, Palcsey S, Moalli P. Deterioration in biomechanical properties of the vagina following implantation of high-stiffness prolapse mesh.  2013 Jan;120(2):224-32.  PMCID: PMC3530836.
  • Liang R, Abramowitch S, Knight K, Palcsey S, Nolfi A, Stein S, Moalli P. Vaginal degeneration following implantation of synthetic mesh with increased stiffness.  2013 Jan:120(2):233-43.  PMCID: PMC3531826.
  • Liang R, Zong W, Palcsey S, Abramowitch S, Moalli P. Impact of prolapse meshes on the metabolism of vaginal extracellular matrix in rhesus macaque. Am J Obstet Gynecol. 2015, 212(2):174.e1-7. PMCID: PMC4312539
  • Brown BN, Mani D, Nolfi AL, Liang R, Abramowitch SD, Moalli PA. Characterization of the host inflammatory response following implantation of prolapse mesh in rhesus macaque.  Am J Obstet Gynecol. 2015 Nov;213(5):668.e1-668.e10. doi: 10.1016/j.ajog.2015.08.002. Epub 2015 Aug 7.  PMCID: PMC4631685
  • Barone WR, Amini R, Maiti S, Moalli PA, Abramowitch SD. The impact of boundary conditions on surface curvature of polypropylene mesh in response to uniaxial loading.  J Biomech. 2015 Jun 25;48(9):1566-74. Epub 2015 Mar 16. PMCID: PMC4550315
  • Barone WR, Moalli PA, Abramowitch SD. Textile Properties of Synthetic Prolapse Mesh In Response to Uniaxial Loading. Am J Obstet Gynecol. 2016 Mar 18; [Epub ahead of print] PMCID: PMC5161096
  • Nolfi A, Brown BN, Liang R, Palcsey SL, Bonidie MJ, Abramowitch SD, Moalli PA. Host Response to Synthetic Mesh in Women with Mesh Complications. Am J Obstet Gynecol. 2016 Aug;215(2):206.e1-8. Epub 2016 Apr 16. PMCID: PMC5201165
  • Knight K, Moalli P, Abramowitch SD. Preventing Mesh Pore Collapse by Designing Mesh Pores with Auxetic Geometries: A Comprehensive Evaluation via Computational Modeling. J Biomech Eng. 2018 Jan 19. doi: 10.1115/1.4039058. [Epub ahead of print] PMID:29350744
  • Liang R, Knight K, Barone W, Powers RW, Nolfi A, Palcsey S, Abramowitch S, Moalli PA. Extracellular matrix regenerative graft attenuates the negative impact of polypropylene prolapse mesh on vagina in rhesus macaque.  Am J Obstet Gynecol. 2017 Feb; 216(2): 153.e1–153.e9. Published online 2016 Sep 8. PMCID: PMC5290183
  • Liang R, Knight K, Easley D, Palcsey S, Abramowitch S, Moalli PA. Towards rebuilding vaginal support utilizing an extracellular matrix bioscaffold.  Acta Biomaterialia; 2017; 57:324-333. PMCID: PMC5639927

For additional publications, see: