title: Biomechanical properties of vaginal tissue in women with pelvic organ prolapse.
abstract: OBJECTIVE
  To compare biomechanical properties of vaginal tissues between women with and without pelvic organ prolapse (POP) and investigate factors that may influence these properties.
  
  
  METHODS
  Forty patients submitted to POP surgery and 15 non-POP cadavers were evaluated. The tissue was excised from anterior and posterior middle third vagina. The biomechanical properties considered were stiffness (E) and maximum stress (S), and they were evaluated by means of uniaxial tension tests.
  
  
  RESULTS
  POP patients were associated with higher values of E (13.1 ± 0.8 vs. 9.5 ± 0.7 MPa; p < 0.001) and S (5.3 ± 0.5 vs. 3.2 ± 0.9 MPa; p < 0.001) in the anterior vaginal wall compared to the posterior wall. In contrast, non-POP women presented lower values of E (6.9 ± 1.1 vs. 10.5 ± 1.0 MPa; p = 0.01) and S (2.6 ± 0.4 vs. 3.5 ± 0.4 MPa; p = 0.043) in the anterior wall. The occurrence of POP was the only independent predictor of higher values of E and S in anterior vaginal samples (p = 0.003 and p = 0.008, respectively). Women with severe anterior vaginal prolapse presented higher levels of E and S in the anterior sample compared to those with lower POP stages (p = 0.001 and p = 0.01; respectively).
  
  
  CONCLUSIONS
  Women with POP present significant changes of biomechanical properties in the vagina.
authors.affiliation: Department of Gynecology and Obstetrics, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Martins
authors.forename: Agnaldo
authors.initials: A
authors.lastname: Lopes Silva-Filho
authors.forename: Andrea Moura
authors.initials: AM
authors.lastname: Rodrigues Maciel da Fonseca
authors.forename: Agostinho
authors.initials: A
authors.lastname: Santos
authors.forename: Liliana
authors.initials: L
authors.lastname: Santos
authors.forename: Teresa
authors.initials: T
authors.lastname: Mascarenhas
authors.forename: Renato M
authors.initials: RM
authors.lastname: Natal Jorge
authors.forename: António J M
authors.initials: AJ
authors.lastname: Ferreira
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D004548:Elasticity / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D010298:Parity; D056887:Pelvic Organ Prolapse / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D013314:Stress, Mechanical; D014596:Uterine Prolapse / Q000209:etiology / Q000503:physiopathology*; D014621:Vagina / Q000503:physiopathology*; D055815:Young Adult