Healing effect of acellular dermal matrixes for repair of abdominal wall defects in a rat model.

BACKGROUND Although acellular dermal matrix (ADM) is a widely used graft material for abdominal wall repair, differences in processing methods might yield different healing activities. The aim of this study was to compare the healing effects of two human-derived ADM prototypes in abdominal wall reconstruction. MATERIALS AND METHODS A standardized 15×50 mm abdominal wall defect was created in 28 Sprague-Dawley rats, which were then implanted with either an EDTA-treated ADM prototype or a salt/solvent-treated ADM prototype. Adhesion formation, tensile strength, tissue ingrowth, neovascularization and inflammatory cell infiltration were then assessed in the two ADM prototypes during the experimental period. RESULTS In both ADM prototypes, mild adhesion formation with the omentum was observed at autopsy at one and four weeks post-implantation. Tensile strength was higher at four weeks post-implantation than that at one week post-implantation. Good neovascularization was observed in the periphery of the ADM, but not in the ADM core. Muscles facing the ADM and muscle-ADM junctions were thick and long at one week post-implantation and had been replaced by new host collagen at four weeks post-implantation. No mesothelial cells at the margins were observed at one and four weeks post-implantation. The thickness of the remaining implanted ADM at four weeks post-implantation was less than that at one week post-implantation. There were no statistical differences between the two ADM prototypes in terms of adhesion formation, tensile strength, tissue ingrowth, neovascularization and inflammatory cell infiltration during the experimental period. CONCLUSION These results indicate that both ADM prototypes are applicable implant materials for repair of abdominal wall defects.