XCT and DVC-based modelling and characterisation of surgical mesh implants for hernia repair

Details

Supervisors

Kerckhofs, Greet

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil mécanicien, à finalité spécialisée

Abstract

Hernia repair is among the most frequently performed surgeries and, most often, involves the implantation of a synthetic surgical mesh. Nearly one in three patients require revision surgery due to hernia recurrence alone, which comes at a high cost to the patient in terms of discomfort, disability, and financial burden [1]. The link between the mesh (micro)structure on one hand and the material behaviour (ex vivo mechanical behaviour) and clinical outcome (in vivo functional behaviour after tissue ingrowth) on the other hand is still not fully understood. This study improves the understanding of the mechanical behaviour of hernia repair meshes by developing an FE model of the unit cell of one of the most commonly available commercial mesh, Bard® mesh. First, X-ray microCT (XCT) and 4D-XCT techniques were used to image the mesh at subsequent in situ loading steps, assessing the structural deformations of the mesh in consideration. At the next step, a digital volume correlation (DVC) protocol was optimised to quantify, based on the 4D-XCT data, the local strains inside the mesh. Finally, the 3D structural information of the mesh, obtained by XCT, was used to develop an XCT-based finite element model of the mesh that allowed mechanical simulations. The model was validated by comparing its outcome with the 4D-XCT data and the DVC results. The reaction force generated by current model has error percentage of 10.28 percent when compared with the experimental values. Drawbacks of the in-silico model are also identified, and suggestions are made to further optimise the model.