Fabrication, characterization and application of polypropylene macroporous mesh for repairing pelvic floor defects

Abstract

The application of mesh to reconstruct pelvic floors is considered a state-of-the-art method for the treatment of pelvic floor dysfunction. Polypropylene (PP) is the most frequently used synthetic graft material in gynecology departments due to its good mechanical property and non-degradability. Pelvic repairing meshes are required to have good biocompatibility, stability and low shrinkage with sufficient softness. Meshes should also adhere to surrounding tissues to support pelvic organs after implantation. This work designed two kinds of lightweight PP macroporous meshes with different structures. The meshes were designed based on analyzing properties of Gynemesh® PS, which is a common pelvic repairing mesh in clinical use. The requirements of mesh design were as follows: mesh weight <45 g/m2, pore size >75 µm, porosity >60%. Two kinds of meshes were fabricated according to design requirements and named the S1 mesh and S2 mesh. Several structural parameters, including thickness, weight, pore size, porosity and mechanical properties, including bursting strength, tensile strength, suture pulling off force and flexibility, were tested and analyzed. S1 mesh and S2 mesh were then implanted in the onlay position of rabbits for 90 days. The biocompatibility was evaluated through operation situation, postoperative recovery, mesh adhesion, shrinkage, histological evaluation of mesh and surrounding tissues. The results revealed that the two kinds of meshes were both beneficial to promote tissue growth; most animals recovered well. However, S1 mesh had greater shrinkage, while there existed one case of infection in the S2 mesh group because of mesh folding.