A novel method for evaluating the tensile behavior isotropy of surgical meshes based on the analysis of the polar graph of tensile properties using image processing method

Abstract

The most common hernia treatment method is using a surgical mesh. The functional properties of surgical meshes, including structural and mechanical properties affect mesh performance. Anisotropy of the tensile behavior of the surgical mesh influences the hernia treatment process. In this research, a novel index named ‘isotropy index’ is introduced based on the analysis of the polar graph of the tensile properties of surgical meshes. The isotropy index, which is expressed in percent, was defined as the ratio of the polar diagram area of the tensile elastic modulus to the area of the circle surrounding the polar graph and calculated using the meshes' tensile elastic modulus in five directions(0°(course), 30°, 45°, 60°, and 90°(wale)) using the image processing method. For this purpose, common net warp-knitted fabrics in surgical mesh production were produced with five various knit patterns(quasi-Sandfly, Tricot, Pin-hole-net, Sandfly, and quasi-Marqussite) using polypropylene monofilament yarns, and their tensile properties were analyzed in various directions(0°(course), 30°, 45°, 60°, and 90°(wale)). Results revealed that the quasi-Sandfly mesh is the most isotropic(57.74%), and the quasi-Marqussite mesh is the most anisotropic(17.12%) among evaluated surgical meshes. Tricot mesh(54.98%), Sandfly mesh(49.17%), and Pin-hole-net mesh(46.41%) in terms of the tensile behavior isotropy are between quasi-Sandfly mesh and quasi-Marqussite mesh. The Sandfly mesh has the closest isotropy index to the abdominal wall tissue. Considering the importance of the lightness, adequate porosity, larger pore size, and closeness of the mesh’ isotropy index to abdominal wall tissue for enhancing mesh functional properties, the Sandfly mesh was selected as the best-knit pattern for surgical mesh.