A comparison of soft-tissue substitutes.

The fate of the Zyderm II, Zyplast, Vicryl, and chromic gut was histologically examined up to 1 year following subcutaneous implantation into rats. Our data demonstrated both Zyderm II and Zyplast to be inert materials without inflammatory response; there was no difference in long-term persistence between these two collagens. Both Vicryl and chromic gut implants caused an intense inflammatory response at 1 month, and Vicryl was completely resorbed before 6 months. The degree of inflammation associated with chromic gut diminished over time, and approximately 67% of the material persisted without reaction up to 1 year.