Surface orientation effects on bending properties of surgical mesh are independent of tensile properties.

INTRODUCTION Current mechanical testing of surgical mesh focuses primarily on tensile properties even though implanted devices are not subjected to pure tensile loads. Our objective was to determine the flexural (bending) properties of surgical mesh and determine if they correlate with mesh tensile properties. METHODS The flexural rigidity values of 11 different surgical mesh designs were determined along three textile directions (machine, cross-machine, and 45° to machine; n = 5 for each) using ASTM D1388-14 while tracking surface orientation. Tensile testing was also performed on the same specimens using ASTM D882-12. Linear regressions were performed to compare mesh flexural rigidity to mesh thickness, areal mass density, filament diameter, ultimate tensile strength, and maximum extension. RESULTS Of 33 mesh specimen groups, 30 had significant differences in flexural rigidity values when comparing surface orientations (top and bottom). Flexural rigidity and mesh tensile properties also varied with textile direction (machine and cross-machine). There was no strong correlation between the flexural and tensile properties, with mesh thickness having the best overall correlation with flexural rigidity. CONCLUSIONS Currently, surface orientation is not indicated on marketed surgical mesh, and a single mesh may behave differently depending on the direction of loading. The lack of correlation between flexural stiffness and tensile properties indicates the need to examine mesh bending stiffness to provide a more comprehensive understanding of surgical mesh mechanical behaviors. Further investigation is needed to determine if these flexural properties result in the surgical mesh behaving mechanically different depending on implantation direction. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 854-862, 2018.

引言 目前对外科补片的力学测试主要集中在拉伸性能上，尽管植入的器械不会承受纯拉伸载荷。我们的目的是确定外科补片的弯曲性能，并确定其是否与补片的拉伸性能相关。 方法 使用ASTM D1388 - 14标准，在追踪表面取向的同时，沿三个织物方向（机器方向、横向机器方向以及与机器方向成45°；每个方向n = 5）测定11种不同外科补片设计的抗弯刚度值。同时使用ASTM D882 - 12对相同的样本进行拉伸测试。进行线性回归以比较补片的抗弯刚度与补片厚度、面质量密度、丝直径、极限拉伸强度和最大伸长率。 结果 在33个补片样本组中，当比较表面取向（顶部和底部）时，30个组在抗弯刚度值上有显著差异。抗弯刚度和补片拉伸性能也随织物方向（机器方向和横向机器方向）而变化。弯曲性能和拉伸性能之间没有很强的相关性，其中补片厚度与抗弯刚度的整体相关性最好。 结论 目前，市售的外科补片上没有标明表面取向，并且同一种补片根据加载方向的不同可能表现不同。抗弯刚度和拉伸性能之间缺乏相关性表明需要检测补片的弯曲刚度，以便更全面地了解外科补片的力学行为。需要进一步研究以确定这些弯曲性能是否会导致外科补片根据植入方向的不同而在力学上表现不同。© 2017威利期刊公司。《生物医学材料研究B部分：应用生物材料》，106B: 854 - 862，2018。