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.