Article,
Stresses produced by different textile mesh implants in a tissue equivalent
BioNanoMaterials, 15 (1-2): 25--30 (January 2014)
DOI: 10.1515/bnm-2014-0003
Abstract
In pelvic floor surgery mesh implants are commonly used to recover incontinence and prolapse. There is a huge number of different mesh implants that have largely different mechanical properties, like their dimension, their material, the way of weaving, the number of threads used for the weaving, thickness of the threads, pore size and orientation of the pores. Due to the numerous differences the mesh implants already have been mechanically investigated with respect to all those properties and uniaxial tension tests, tearing tests, bending burst tests and other loading experiments have been conducted to determine maximum forces, strain, stress, pull-out strength, the degree of anisotropy, material parameters and hysteresis. In this paper we compare two different meshes, the Gynecare (GC) of Ethicon, USA and SIS direct (SD) of FEG Textiltechnik, Germany. We choose those meshes because they have a considerably different structure which we identifoed to be very important by means of their pull-out behavior and stress distribution in the surrounding tissue. We present an experimental method for measuring the pull-out strength and visualizing the shear stresses in a muscle tissue equivalent using photoelasticity. The meshes are embedded into a transparent gelatin block. Gelatin serves as a tissue that behaves similar to muscle tissue. The end of the mesh and another textile tissue embedded at the other end of the gelatin block have been clamped into a tension machine. Applying tension to the mesh and looking at the gelatine block through a filter leads to colorful isochromatic lines that represent lines of equal shear stresses.
