Background: Acellular porcine dermis has been used as a soft-tissue substitute in Europe since 1998 and in the United States since 2000. Processing renders the composite acellular, reducing antigenicity and crosslinking the dermal collagen. The purpose of this study was to determine the long-term histologic response of this material to the transfer into a subcutaneous soft-tissue location in an in vivo mouse model.
Methods: A total of 24 mice (ICR strain) underwent an initial procedure transplanting a segment of acellular porcine dermis into a dorsal subcutaneous pocket. The implants were examined for qualitative characteristics including rigidity, migration, inflammation, and healing response. Composites of skin, subcutaneous tissue, implant, and underlying muscle were harvested for histologic evaluation. The specimens were analyzed for inflammatory response, degree, and character of tissue incorporation and degree of implant resorption.
Results: One of the 24 animals studied experienced extrusion of the implant. The remaining 23 implants persisted within their respective hosts until the time the animals were killed. The volume and weight of all of the implants remained unchanged from the preoperative to postoperative measurements. Dystrophic calcification and bone formation was seen at 12 months.
Conclusions: The results do not suggest characteristics optimal for implants used in soft-tissue augmentation for the purpose of aesthetics. The porcine dermis would appear from these results to be better suited for situations that require strength and permanence of the implant.