Computational framework to model and design surgical meshes for hernia repair

Abstract

Surgical procedures for hernia surgery are usually performed using prosthetic meshes. In spite of all the improvements in these biomaterials, the perfect match between the prosthesis and the implant site has not been achieved. Thus, new designs of surgical meshes are still being developed. Previous to implantation in humans, the validity of the meshes has to be addressed, and to date experimental studies have been the gold standard in testing and validating new implants. Nevertheless, these procedures involve long periods of time and are expensive. Thus, a computational framework for the simulation of prosthesis and surgical procedures may overcome some disadvantages of the experimental methods. The computational framework includes two computational models for designing and validating the behaviour of new meshes, respectively. Firstly, the beam model, which reproduces the exact geometry of the mesh, is set to design the weave and determine the stiffness of the surgical prosthesis. However, this implies a high computational cost whereas the membrane model, defined within the framework of the large deformation hyperelasticity, is a relatively inexpensive computational tool, which also enables a prosthesis to be included in more complex geometries such as human or animal bodies.

Synthetic surgical meshes used in abdominal wall surgery: Part I-materials and structural conformation

“…In general, the definition of mesh mechanical properties depends on different factors, like structural conformation, material properties, and fiber structure. To our knowledge, a comprehensive study to evaluate the influence of such parameters on the overall mesh mechanical behavior and to associate a certain texture to specific mechanical features, has yet to be performed, with few exceptions …”

“…To our knowledge, a comprehensive study to evaluate the influence of such parameters on the overall mesh mechanical behavior and to associate a certain texture to specific mechanical features, has yet to be performed, with few exceptions. 46 However, some structural characteristics are discussed in the literature in terms of mesh porosity and anisotropy. Porosity is a key parameter for the evaluation of synthetic mesh performances, insofar as pore size has been even proposed as a standard criterion for mesh classification.…”

Numerical simulation of breast reduction with a new knitting condition

“…where a g is the gravity acceleration, c the Chassaignac coefficient, and the density. Condition (7) corresponds to fix the breast displacement on curve D , while condition (8) maintains the breast on the trunk. Condition (9) is the stick condition that preserves the junction between the left and right interfaces previously joined in the suturing process.…”

“…Condition (7) yields that f n D P n for any P n 2 D , while relation (8) implies that for any P n 2 C , we set f ny D 0 to maintain interface C on the trunk plane y D 0. Constraint (9) means that the two interfaces previously joined and stuck will preserve their relative position, and we define function G in the following way.…”

Synthetic surgical meshes used in abdominal wall surgery: Part II—Biomechanical aspects

“…A reliable mesh model should take into account the nonlinear response of the mesh, anisotropy, viscoelastic properties, and mechanical changes due to pore structural collapse under cyclic loading . Some computational models reproduce mesh structure by considering the geometrical arrangement and knitting pattern of the filaments . However, these models are extremely complex and their implementation in a computational model of the abdominal region would determine computational difficulties.…”