Effect of a fascial tissue interface on silicone implant capsule formation--a preliminary experimental study

The effects of a fascial tissue interface on silicone implant capsule formation were studied in a rabbit model. In two experimental groups, the thoracodorsal fascia was harvested either as a free graft (Group Ia) or as a fascial flap (Group Ib), then wrapped around silicone implants prior to subcutaneous placement. In each instance the fascia was configured to form a biological interface between the implant and surrounding soft tissue. The resulting capsules were macroscopically and histologically compared to a control group (Group II) of unwrapped silicone implants which were inserted subcutaneously. The cellular response to textured and smooth surfaces on opposing sides of each implant was also separately investigated in both study groups. Statistical analysis was performed using a Student's t-test. The capsules formed in each experimental group were observed to be thinner and less cellular when compared to the unwrapped control group (P<0.05), while no demonstrable differences between fascial flap and free graft subgroups were found (P>0.05). Furthermore, less cellularity and reduced capsule thickness were observed in the textured implant capsule surfaces in both fascial flap and free graft groups when compared to smooth implant capsule surfaces (P<0.05). Our preliminary study findings using a fascial tissue interface, either as a flap or a free graft, reveal cellular architectural characteristics of the resulting capsule that may be significant in minimising capsular contraction around silicone implants.