Fibrous capsule caused by silicone gel:a histological observation after transplantation

Objective To investigate the histological changes of fibrous capsule caused by silicone gel after transplantation.Methods Silicone gels were implanted subcutaneously in four legs in 16 SD rats.One month later the silicone gel was removed and the fibrous capsule was left at the original sites or transplanted to other sites; the histological changes and fibrous structure were observed at 3 days,1 weeks,1 months and 3 months later. Results Slight redness and edema were noticed at all transplanted sites and disappeared about one week later.The incisions healed well and the local tissues were soft;no removal of the transplanted capsules was noticed.The thickness and absorbance rate of the transplanted and untransplanted capsules were similar in Group A(both P0.05),but they were significantly different in those of Group B,C,and D(all P0.05).The thickness and absorbance rate of transplanted capsules in Group A were significantly different from those of the other 3 groups(all P0.05);there was no significant difference between those of Group B and C,Group C and D(all P0.05).The intensity,positive area rate,and absorbance rate of the transplanted capsules in Group A were sig- nificantly different from those of the other 3 groups(all P0.05);there was no significant difference between Group B,C and D(all P0.05)and between the transplanted and untransplanted capsules in Group A(all P0.05);and there was significant difference between the transplanted and untransplanted capsules in Group B,C, and D(all P0.05).Conclusion Silicone gel as the foreign body can induce the formation of the fibrous cap- sules,which can be gradually absorbed after the removal of the foreign body.The silicone gel-induced fibrous cap- sule might be a promising autograft in the future.(Shanghai Med J,2007,30:618-620)