Analysis of the stress relaxation of synthetic surgical meshes in view of loading direction

Abstract

Surgical mesh is a porous fabric, which is used for healing hernia, pelvic organ prolapse, and urinary incontinence. In the present study, synthetic surgical meshes with five different warp knitted structures, including Tricot, Pin hole-net, Sandfly, quasi-Sandfly, and quasi-Marqussite, have been fabricated using polypropylene monofilament, and the effect of loading direction on the stress relaxation of the meshes in orthogonal directions have been considered in comparison with human fascia. The results revealed that loading direction has a significant effect on the stress relaxation of the mesh. Different stress relaxation of various mesh structures in orthogonal directions can be attributed to the pore shape (pore angle) and underlap angle in the structure of the mesh. Except for Pin-hole-net mesh, all mesh structures displayed a constant and independent level of orthotropy to the relaxation time. Moreover, Tricot mesh and quasi-Sandfly mesh, with the level of orthotropy near to1, revealed almost isotropic viscoelastic properties. Overall, the quasi-Marqussite mesh was proposed as the most desirable surgical mesh due to its lighter weight, higher porosity, lower stress relaxation, and closest level of othotropy to the human fascia.