A non-biological model system to simulate the in vivo mechanical behavior of prosthetic meshes

A simple model system using synthetic materials was developed to simulate the in vivo mechanical behavior of prosthetic meshes. Two types of prosthetic meshes, SPMM (heavy-weight) and Gynemesh M (light-weight, partly absorbable) were embedded in dry conditions in an elastomeric matrix. These composites were characterized using two different testing configurations, i.e., uniaxial and biaxial tension. Stiffness parameters were calculated from the non-linear membrane tension versus stretch curves at different levels of membrane tension. The present model system qualitatively reproduces and even clarifies - as it is not affected by biological scatter - the findings of an analogous animal study (full thickness abdominal wall defect rabbit model). Biaxial tangent moduli are higher for SPMM than for Gynemesh M. A ranking of meshes according to uniaxial tangent moduli depends on the load level. At low tensions SPMM is stiffer than Gynemesh M, at moderate levels SPMM is more compliant than Gynemesh M. Stiffness values of meshes ingrown in native rabbit abdominal wall tissue are quantitatively determined based on data from the present protocol. Experiments using mesh elastomer composites were qualified as an effective tool for a mechanical characterization of prosthetic meshes. They are useful for an engineering optimization of textile meshes before a final validation in animal studies.