EFFECTIVE POROSITY OF 3D PRINTED SURGICAL MESHES

Abstract Introduction According to previous studies, pore size and geometry are crucial factors to assure good clinical results for surgical meshes [refs]. Although commercial surgical meshes are commonly knitted, 3D printing has recently been used to provide additional properties to them [refs]. In general, the mechanical properties of 3D printed meshes are worse, but geometrical control is better than in knitted ones. In this study, a comparison of effective porosity between knitted and 3D printed surgical meshes was performed. Methods Pore size and geometry were characterized through optical brightfield microscopy (Nikon E100) and quantified using ImageJ v.1.53e. Several geometries of 3D printed meshes with polypropylene (Prusa i3 MK3 and Smartfil filament) and commercial polypropylene Assumesh meshes (Assut Europe) were evaluated. The 3D printed geometries were triangular and honeycomb while the commercial meshes were knitted. Results 32.38, 18.65 and 17.26% of the total area of the commercial, triangular and honeycomb meshes were porous, respectively. Although effective porosity was homogeneous on commercial meshes (2.71±0.07 mm2), pore size was smaller in honeycomb (0.088±0.071 mm2) and bigger in triangular (0.201±0.063 mm2) than in commercial meshes (0.105±0.030 mm2). Conclusions Some imperfections are generated during the extrusion of filaments that contributes to non-uniform pores in 3D printed meshes. Hence, a post-processing of meshes will be recommended to take advantage of the higher precision of 3D printing.