Tissue Reactions to Heterogenic and Allogeneic Acellular Dermal Matrix Mesh Placed in the Vesicovaginal Space in a Rabbit Model.
This study is aimed at investigating the tissue reactions of heterogenic and allogeneic acellular dermal matrix (ADM) mesh implanted in the vesicovaginal space in a rabbit model. Twenty eight rabbits were implanted with heterogenic or allogeneic mesh, respectively, in the vesicovaginal space, and 4 served as the no-implantation control group. Rabbits were sacrificed at 7, 30, and 90 days after implantation. Histopathological study and immunohistochemical examination for collagen were performed. Heterogenic but not allogeneic mesh was identifiable at 90 days. In the allogeneic group, neovascularization was observed from day 7 after implantation. A chronic inflammatory reaction was noted in the heterogenic group at 30 days that decreased at 90 days. Inflammation was less in the allogeneic group, but giant cells and fibroblasts were present. With respect to collagen, the heterogenic mesh remained structurally unchanged at 90 days, while new collagen fibers were observed in the allogeneic group from day 7. The immunological outcomes of heterogenic and allogeneic ADM mesh are different. Heterogenic mesh induces a chronic inflammatory reaction at day 30 after implantation, and maintains its original form longer. Allogeneic mesh is associated with new collagen generation, but degrades earlier.