Improved textured surfaces for implantable prostheses.

Abstract

Textured surfaces have been shown to reduce scar tissue formation around implanted prostheses compared with identical smooth surface controls in applications such as compliance chambers for artificial heart systems. The authors have developed and evaluated alternative textured surfaces to the polyester velour surface that has been used on those devices. These new textured surfaces are fabricated with materials known to provoke a diminished tissue response compared with polyester fibers. Two new textured surfaces have been examined: a surface composed of extruded 25 micron diameter polyurethane fibrils (PF) woven into a fabric, and an integrally textured silicone rubber surface (TS) with nonfibril geometry applicable to silicone rubber implants such as mammary prostheses. In both cases, tissue fixation to the textured surface depends primarily on mechanical interdigitation with the complicated surface morphology of the implant rather than on chemical bonding. Two types of control were employed: polyester velour fabric (PV) as a textured surface, and smooth silicone rubber (SS). Each surface was first characterized with scanning electron microscopy (SEM), and test specimens consisting of 1 cm diameter by 1 mm thickness disks were then prepared and implanted subcutaneously in a series of 16 adult New Zealand white rabbits. After 8 weeks the samples were explanted and histologic sections prepared for analysis. In all cases a thin, organized tissue capsule surrounded the implant. While the tissue capsule on average was thinner surrounding the textured surface implants, variations in the individual host response were more significant. Tissue attachment was minimal with SS, present with PF, and greatest with TS and PV.(ABSTRACT TRUNCATED AT 250 WORDS)