Vaginal Tissue Properties versus Increased Intra-Abdominal Pressure: A Preliminary Biomechanical Study

Background/Aims: This study aims to evaluate the pelvic floor (PF) tension response during simulated increased intra-abdominal pressure (IAP) and the vaginal biomechanical properties. Methods: A 3-dimensional computational finite element model for PF was developed based on magnetic resonance imaging from a nulliparous healthy volunteer. The model was used to simulate an IAP of 90 cm H 2 O and to evaluate the PF stresses in the longitudinal and transversal axes. The vaginal samples were obtained from 15 non-prolapsed female cadavers. A uniaxial tensile test to obtain stiffness and maximum stress of vaginal tissue in the longitudinal and transversal axes was performed. Results: The simulated IAP was associated with a similar PF stress state in the longitudinal and transversal axes. The stiffness and maximum stress in vaginal tissues presented a great variability between subjects. There was no difference in the vaginal tissue elasticity (6.2 ± 1.5 vs. 5.4 ± 1.1 MPa; p = 0.592) and maximum stress (2.3 ± 0.5 vs. 2.6 ± 0.9 MPa; p = 0.692) regarding the measurements in the longitudinal and transversal axes. Conclusion: The isotropic biomechanical behavior of vagina is in agreement with the PF stress state response during increased IAP.