Physicomechanical evaluation of absorbable and nonabsorbable barrier composite meshes for laparoscopic ventral hernia repair.

BACKGROUND: This study aimed to compare the physicomechanical properties of composite prostheses for laparoscopic ventral hernia repair (LVHR) through standard testing and a proposed classification system. METHODS: Seven prostheses (four with absorbable barriers and 3 with nonabsorbable barriers) were evaluated. The barrier layer was removed, after which the area of the interstices and the diameter of the filaments were determined. The barrier layer was left intact during thickness, density, suture retention strength, tear resistance, uniaxial tensile, and ball-burst testing. Specimens were oriented parallel or perpendicular to their longest dimension during testing. One-way analysis of variance (ANOVA) with Tukey's posttest or an unpaired, two-tailed t-test was performed to determine whether differences existed due to mesh or orientation, and a p value<0.05 was considered significant. RESULTS: Significant differences were observed between mesh types and due to the orientation of the mesh during testing. Of the absorbable barrier meshes, Bard Sepramesh IP Composite demonstrated the greatest suture retention and tear strengths, followed by C-QUR mesh. Of the permanent barrier meshes, DUALMESH demonstrated the greatest suture retention strength in the perpendicular direction, followed by Bard Composix E/X. DUALMESH and Bard Composix E/X demonstrated equivalent suture retention strength in the parallel direction and equivalent tear resistance in both testing directions. All meshes demonstrated tensile strengths greater than the physiologically relevant range of 16-32 N/cm. CONCLUSIONS: This study provided a basic understanding of how the structural aspects of each mesh design influence functionality. Differences between composite barrier prostheses commonly used for LVHR were observed due to barrier type, mesh type, and orientation. A set of standard testing techniques and a classification system also were presented to define fully the properties of these materials.

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 mm² for ProLite (Atrium Medical Corp) and C-QUR Lite (Atrium Medical Corp) Large to 4.10 ± 0.06 mm² for ULTRAPRO (Ethicon), and filament diameters ranged from 99.00 ±8.1 µm for ProLite Ultra (Atrium Medical Corp) and C-QUR Lite Small to 338.8 ± 3.7 µm for Parietex Flat Sheet TEC (Covidien). These structural characteristics influenced biomechanical properties such as tear resistance and tensile strength. ProLite 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.