Page 287 - Prevention and Treatment of Incisional Hernia- New Techniques and Materials

Introduction
Many factors are of in uence on the functional outcome of abdominal wall repair, such as patient characteristics, site of implantation, the presence of contamination, and the chosen mesh material. Especially in the presence of bacterial contamination, repair of abdominal wall defects is a continuing challenge for surgeons. Contamination can be caused by intra-abdominal and surgical site infection, incarcerated and strangulated hernia, concomitant bowel surgery, the presence of a colostomy, acute evisceration, and open abdomen. Introduction of synthetic meshes in abdominal wall repair signi cantly decreased recurrence rates(1, 2). However, implantation of a synthetic prosthesis into a contaminated environment generates an increased risk for infection(3, 4). Mesh infection often necessitates removal of the mesh, leaving an abdominal wall de cit, sometimes larger than the original hernia, and closure can only be accomplished with contact of the mesh with the intra-abdominal content. Recommendations on mesh selection have been developed by the Ventral Hernia Work Group in 2008(5). In case of ventral hernia repair with mesh implantation in patients with grade-3 and -4 risk of surgical site infection, biological mesh is recommended.
Biological meshes are extracellular sca olds, processed from animal (bovine or porcine) small intestine submucosa, pericardium, or dermis. The donor tissue is said to be cleared of cells and immunogenic particles, after which a sca old of extracellular matrix (ECM) remains. After implantation, the sca old is gradually vascularized and remodelled into the host tissue while degradation of the ECM takes place(6, 7). To increase biomechanical strength, chemical crosslinking of the biological mesh can be conducted. Crosslinking stabilizes the 3- dimensional structure of the ECM. This improves withstanding of enzymatic degradation of the ECM, which can be accelerated because of in ammation or infection at the implantation site(8-10). Initial animal and clinical data seemed promising; however, compelling evidence is lacking as these data mainly report on clean cases and short follow-up with only a small portion in contaminated cases(11). Furthermore, recent clinical reports have been published on infectious complications of both non-crosslinked and crosslinked meshes(12-17).
The objective of this experimental study was to investigate the infectious complications and functional outcome of crosslinked and non-crosslinked
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Infection susceptibility of biological meshes
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