title: Biaxial Mechanical Evaluation of Absorbable and Nonabsorbable Synthetic Surgical Meshes Used for Hernia Repair: Physiological Loads Modify Anisotropy Response.
abstract: The aim of this study was to obtain information about the mechanical properties of six meshes commonly used for hernia repair (Surgipro(®), Optilene(®), Infinit(®), DynaMesh(®), Ultrapro™ and TIGR(®)) by planar biaxial tests. Stress-stretch behavior and equibiaxial stiffness were evaluated, and the anisotropy was determined by testing. In particular, equibiaxial test (equal simultaneous loading in both directions) and biaxial test (half of the load in one direction following the Laplace law) were selected as a representation of physiologically relevant loads. The majority of the meshes displayed values in the range of 8 and 18 (N/mm) in each direction for equibiaxial stiffness (tangent modulus under equibiaxial load state in both directions), while a few achieved 28 and 50 (N/mm) (Infinit (®) and TIGR (®)). Only the Surgipro (®) mesh exhibited planar isotropy, with similar mechanical properties regardless of the direction of loading, and an anisotropy ratio of 1.18. Optilene (®), DynaMesh (®), Ultrapro (®) and TIGR (®) exhibited moderate anisotropy with ratios of 1.82, 1.84, 2.17 and 1.47, respectively. The Infinit (®) scaffold exhibited very high anisotropy with a ratio of 3.37. These trends in material anisotropic response changed during the physiological state in the human abdominal wall, i.e. T:0.5T test, which the meshes were loaded in one direction with half the load used in the other direction. The Surgipro (®) mesh increased its anisotropic response (Anis[Formula: see text] = 0.478) and the materials that demonstrated moderate and high anisotropic responses during multiaxial testing presented a quasi-isotropic response, especially the Infinit(®) mesh that decreased its anisotropic response from 3.369 to 1.292.
authors.affiliation: Aragón Institute of Engineering Research (I3A), Mechanical Engineering Department, University of Zaragoza, Zaragoza, Spain.|CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Aragon Health Sciences Institute, Zaragoza, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Cordero
authors.affiliation: Aragón Institute of Engineering Research (I3A), Mechanical Engineering Department, University of Zaragoza, Zaragoza, Spain.|CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Aragon Health Sciences Institute, Zaragoza, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Hernández-Gascón
authors.affiliation: Departament of Medicine and Medical Specialities, Faculty of Medicine and Health Sciences, University of Alcalá, Madrid, Spain.|CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Aragon Health Sciences Institute, Zaragoza, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Pascual
authors.affiliation: Departament of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, University of Alcalá, Madrid, Spain.|CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Aragon Health Sciences Institute, Zaragoza, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Bellón
authors.affiliation: Aragón Institute of Engineering Research (I3A), Mechanical Engineering Department, University of Zaragoza, Zaragoza, Spain.|CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Aragon Health Sciences Institute, Zaragoza, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Calvo
authors.affiliation: Aragón Institute of Engineering Research (I3A), Mechanical Engineering Department, University of Zaragoza, Zaragoza, Spain. fany@unizar.es.|CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Aragon Health Sciences Institute, Zaragoza, Spain. fany@unizar.es.
authors.forename: E
authors.initials: E
authors.lastname: Peña
mesh_terms: D020341:Absorbable Implants; D016880:Anisotropy; D059685:Herniorrhaphy; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D013526:Surgical Mesh
keywords: Anisotropy; Partial hernia defect; Planar biaxial testing; Synthetic surgical mesh