A numerical method for guiding the design of surgical meshes with suitable mechanical properties for specific abdominal hernias.

Abdominal hernia is a common disease, and the most effective treatment of it is using surgical meshes. However, it was found that due to the mismatch of the mechanical properties between the mesh and the tissues around the hernia, there was still a recurrence rate of more than 33% and a high probability of postoperative discomfort. Currently, because of the complex mechanical environment provided by the abdominal tissues and the lack of quantitative research, it is still difficult to select a mesh with suitable mechanical properties for a hernia with specific position and size. Therefore, the purpose of this study is to use numerical models to evaluate the mechanical behavior of both abdominal wall and meshes after repair, and to determine the most suitable mechanical properties of meshes for specific hernias, including elastic modulus and tensile strength. To realize that purpose, defects with different locations and sizes were considered, including defects of 20 mm and 40 mm in diameter on linea alba (LA20 and LA40) and on rectus abdominis (RA20 and RA40), and laparoscopic repair was simulated. The mechanical properties of the most suitable mesh we determined are as follows: suitable modulus for LA20, LA40, RA20 and RA40 are 1 MPa, 3 MPa, 2 MPa and 4 MPa, respectively; suitable tensile strength for LA20, LA40, RA20 and RA40 are 0.35 MPa, 0.89 MPa, 0.77 MPa and 1.43 MPa, respectively. These data could give a standard of mechanical properties which can be referenced in mesh design and evaluation and provide surgeons with treatment advice for specific patients.