Effect of Repetitive Loading on the Mechanical Properties of Synthetic Hernia Repair Materials

Materials characterization and histological analysis of explanted polypropylene, PTFE, and PET hernia meshes from an individual patient

“…The continuous movement of the mesh during normal physical activities may have contributed to a continuous foreign body response, resulting in scar tissue. Mechanical stress and strain have been shown to affect the functionality of mesh materials [7, 23, 24]. Since all three mesh materials, PP, ePTFE, and PET, were implanted in a single patient, all three mesh experienced similar stresses on the abdominal wall that can be transferred to the mesh material.…”

“…It is not conclusive whether this continuous loading and unloading results in reduced tensile strength or increase the strain of the mesh materials. However, a recent in vitro study demonstrated that the tensile strength of e-PTFE and polypropylene mesh was significantly reduced when undergoing continuous loading (1,000 cycles) while the strain increased [23]. These findings suggested that repetitious loading may lead to deterioration of the mechanical properties of the mesh material, which can lead to increase foreign body response and poor functional results.…”

Properties of Meshes used in Hernia Repair: A Comprehensive Review of Synthetic and Biologic Meshes

“…Mechanical properties are important parameters that should be considered when determining the suitability of a particular mesh material for a specific clinical situation. 25 The chemical nature of the fibers, as well as the fabric structure have great effect on the performance of the resulting mesh. 26 These properties are not currently well described in the literature or clearly published by the manufacturers of most available mesh products.…”

Clinically relevant mechanical testing of hernia graft constructs

“…The clinical significance of VitaMesh and Biodesign being stiffer and undergoing lower cyclic dilatational strain than DermaMatrix in planar-biaxial testing is uncertain. However, it is appreciated that ventral hernia repair using an excessively stiff graft could also cause acute separation or failure at the graft-host tissue interface, as well as chronic pain and discomfort at the repair site (Eliason et al, 2011;Leber et al, 1998;Klinge et al, 1999;Klosterhalfen and Klinge, 2013;Doctor, 2006). On the other hand, a graft that undergoes significant cyclic dilatation on repeated loading could cause repair bulging and a functional recurrence of the hernia (Eliason et al, 2011;Sahoo et al, 2014).…”

“…Ball-burst tests (Whitson et al, 1998;Freytes et al, 2005;Deeken et al, 2012;Eliason et al, 2011;Sahoo et al, 2014), planar-biaxial tests (Rohrnbauer and Mazza, 2014;Sun et al, 2005;Lyons et al, 2014;Sahoo et al, 2014), and also inflation tests (Rohrnbauer and Mazza, 2013) can each partly replicate this complex physiologic loading mechanism through their respective modes of loading, and offer different considerations as options for testing hernia grafts. This study used ball-burst and planar-biaxial tests to test hernia grafts as sutured constructs to model the manner in which the grafts are placed and loaded clinically for ventral hernia repair.…”