Page 336 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Chapter 17
the retro-rectus plane was compared to intraperitoneal placement of non- crosslinked biological Strattice® mesh in patients(56).
Biological meshes can roughly be divided into non-crosslinked and crosslinked meshes. After implantation, the sca old of extracellular matrix (ECM) is gradually vascularised and remodelled into the host tissue while degradation of the ECM takes place(62, 63). To increase biomechanical strength, chemical crosslinking of the biological mesh can be conducted. In the experiments in this thesis, a high incidence of mesh infection of crosslinked biological meshes was found. These results are in accordance with clinical reports of infectious complications with use of biological meshes(54, 64-69). The development of infection in crosslinked biological meshes seems comparable to mesh infection in microporous synthetic meshes by preclusion of immune cells(70). The crosslinking of meshes appears to involve the decreasing of pore size in biological meshes such that it promotes a suitable housing for bacteria, while preventing access of macrophages, broblasts, blood vessels, and collagen bres into the pores. The greater the percentage of crosslinking, the more a biological mesh behaves like a microporous mesh. Additionally, crosslinking may lead to encapsulation rather than remodelling of the mesh. It is suggested that some crosslinking processes damage the extracellular matrix and negatively in uence the host response, leading to encapsulation, decreased broblast penetration into the matrix, and little collagen synthesis(71-75). Similar results have been found in patients who have undergone removal of porcine biologic meshes, where little or no evidence of neovascularisation or neocellularisation was detected in crosslinked meshes(76).
The rst studies on biological meshes were mainly case series, with large variations in sample size, mesh material, implantation technique, follow-up, and study endpoints(52, 77). Although the majority of cases were implanted in a non-contaminated environment, these studies have also led to recommendations for use in contaminated surgical elds. In 2010, the Ventral Hernia Working Group (VHWG) recommended use of a biological mesh in cases of a potentially contaminated or infected wound, due to the risk of infectious complications(52). This publication, among other optimistic reports, led to the incorporation of biological meshes into the surgeon’s armentarium, which resulted in widespread implantation of these grafts(52, 78-80). In recent years, authors have started to publish their doubts on biological meshes(53, 59, 77, 81). Biological meshes are often used when a hernia defect must be closed
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