Histological and biomechanical evaluation of implanted graft materials in a rabbit vaginal and abdominal model

Objective: The objective of the study was to describe the histologic and biomechanical changes of implanted dermal collagen graft materials. Study design: Twenty rabbits were randomized into 2 groups (6 and 12 weeks, respectively). Each rabbit had 4 graft segments (human dermis, porcine dermis, porcine collagen-coated polypropylene mesh, and autologous fascia) randomly implanted into the abdomen and the vagina. Biomechanical testing and histologic analysis was performed after recovery of graft segments. Results: Dermal graft segments showed a marked decrease in ultimate strength (84% to 86%) and elastic modulus (73% to 82%) that was significantly different from the decrease seen in autologous fascia or coated synthetic mesh (P < .0008 and P < .0001, respectively). The decrease in ultimate strength was associated with vaginal implantation (P = .057). Dermal graft materials had moderate inflammation and minimal collagen infiltration. Conclusion: The mechanical properties of dermal graft materials decline after implantation. Vaginal implantation may cause a different tissue response to graft material than abdominal implantation. Dermal graft material caused moderate inflammation and minimal collagen ingrowth remote from implantation.