Physicomechanical Evaluation of Polypropylene, Polyester, and Polytetrafluoroethylene Meshes for Inguinal Hernia Repair

BACKGROUND: For meshes to be used effectively for hernia repair, it is imperative that engineers and surgeons standardize the terminology and techniques related to physicomechanical evaluation of these materials. The objectives of this study were to propose standard techniques, perform physicomechanical testing, and classify materials commonly used for inguinal hernia repair. STUDY DESIGN: Nine meshes were evaluated: 4 polypropylene, 1 polyester, 1 polytetrafluoroethylene, and 3 partially absorbable. Physical properties were determined through image analysis, laser micrometry, and density measurements. Biomechanical properties were determined through suture retention, tear resistance, uniaxial, and ball burst testing with specimens tested in 2 different orientations. A 1-way ANOVA with Tukey's post-test or a t-test were performed, with p < 0.05. RESULTS: Significant differences were observed due to both mesh type and orientation. Areas of interstices ranged from 0.33 +/- 0.01 mm(2) for Pro Lite (Atrium Medical Corp) and C-QUR Lite (Atrium Medical Corp) Large to 4.10 +/- 0.06 mm(2) for ULTRAPRO (Ethicon), and filament diameters ranged from 99.00 +/- 8.1 mu m for Pro Lite Ultra (Atrium Medical Corp) and C-QUR Lite Small to 338.8 +/- 3.7 mu m for Parietex Flat Sheet TEC (Covidien). These structural characteristics influenced biomechanical properties such as tear resistance and tensile strength. Pro Lite Ultra, C-QUR Lite Small, ULTRAPRO and INFINIT (WL Gore & Associates) did not resist tearing as effectively as the others. All meshes exhibited supraphysiologic burst strengths except INFINIT and ULTRAPRO. CONCLUSIONS: Significant differences exist between the physicomechanical properties of polypropylene, polyester, polytetrafluoroethylene, and partially absorbable mesh prostheses commonly used for inguinal hernia repair. Orientation of the mesh was also shown to be critical for the success of meshes, particularly those demonstrating anisotropy. (J Am Coll Surg 2011;212:68-79. (C) 2011 by the American College of Surgeons)