Histological response to and immunogenicity of different material patches implanted in rabbit abdominal walls

The high failure rate of traditional procedures of repairing pelvic organ prolapse by using sutures pushes multiple transvaginal mesh delivery systems into the marketplace; however, these are currently without optimal clinical results. We observed the short-term histological changes and the effects of Th1/Th2 cytokines after the implantation in rabbit abdominal walls of five materials, i.e., porcine urinary bladder matrix (UBM), cross-linked UBM, polypropylene mesh, composite cross-linked UBM, and composite UBM, and explored the feasibility of their application to pelvic reconstructive surgery. Grafts were harvested at 1, 2, 4, 8, and 12 weeks after surgery and were processed for histology in order to evaluate the host inflammatory response and the degree of tissue incorporation. Additionally, graft site cytokine levels were determined by reverse transcriptase polymerase chain reaction. The results demonstrate that the two composite groups were associated with an erosion response, whereas the other groups induced a milder response than the composite groups. The Th1/Th2 cytokine mRNA expression levels of the cross-linked UBM group at each time point were similar to that of the sham group, whereas the other groups elicited a more variable expression. The cross-linked UBM showed slow degradation, mild inflammatory response, and low immunogenicity. This suggests that cross-linked UBM is a better material of choice for pelvic reconstructive surgery.