Histological study on acute inflammatory reaction to polyurethane-coated silicone implants in rats

Abstract

PURPOSE: Evaluating histologically the silicone peri-implant coated by polyurethane inflammation associated to the use of anti-microbial and bacterial contamination. METHODS: It was used 35 Wistar rats. The animals were divided in seven groups: I - Control; II - implant cavity contamination with10 bacteria/ml; III - implant cavity contamination with 10 bacteria/ml; IV - implant cavity contamination with 10 bacteria/ml; V - identical contamination to group II and implant immersions in anti-microbial solution; VI - identical contamination in group III and implant immersions in the anti-microbial solution; VII - identical contamination of group IV and implant immersions in anti-microbial solution. It was evaluated morphometrically the peri-implant capsules after 30 days of introduction. RESULTS: The factors with more discriminating power were the giants cells of a strange body and the mononuclear. There was no correlation between the bacterial concentrations and the histological alterations. CONCLUSION: 1) The histological standard of the inflammatory reaction around the silicone implant coated with polyurethan is chronic granulomatosis type of a strange body; 2) There isn´t correlation between concentration of Staphylococcus epidermidis and histological changes; 3) The use of anti-microbial solution decreased the mononuclear cell reactions, with the increase of giant cells in a strange body.

Histological evaluation of capsules formed by silicon implants coated with polyurethane foam and with a textured surface in rats

“…Sixty-four female Wistar rats were used (Rattus norvegicus albinus, Roentia mammalia), weighing 190-250 g, 30 to 90 days of life, distributed in acrylic boxes with 500 cm 3 containing four rats in each with free access to water and specific diet for the species, room temperature and alternating 12 h cycles of light and dark. They were distributed into two groups of 32 and subdivided into four subgroups according to the time of death (30, 50, 70 and 90 days).…”

“…The effectiveness of the anesthesia was assessed by the lack of movement, corneal reflex and motor reaction after holding a clamp on the adipose cushion of one of the hind legs, and a good ventilatory pattern 3 .…”

“…All material introduced into the human body undergoes a foreign body reaction, which occurs in the formation of a fibrous capsule around itself 3 .…”

Capsular Contracture In Silicone Breast Implants: Insights From Rat Models

“…In addition, most studies agree that a 90-days follow up seems to be suitable to evaluate capsular contracture in rats (Tables II and III). The main approaches tested in the studies reviewed in Tables II and III were the effects of smooth and/or textured silicone implants on different histological and biochemical parameters , Vieira et al 2010, Mendes et al 2008, Gancedo et al 2008, Cardenas-Camarena et al 2005, Bergmann et al 2014, Bastos et al 2007b. The results indicate different degrees of fibrosis, fibroblast activation, inflammation, and capsule thickness in periprosthetic tissue (Tables II and III) (Frangou and Kanellaki 2001, Eltze et al 2003, Minami et al 2006, Eltze et al 2006, Adams et al 2006, Cardenas-Camarena et al 2005, Gancedo et al 2008, Chelko et al 2012, Aparecida da Silva et al 2014, Vieira et al 2010.…”

“…Several studies also evidence the link between subclinical infection and capsular contracture occurrence (Bergmann et al 2014, Del Pozo et al 2009, Dobke et al 1995. In the same line, many studies support that bacterial biofilms on breast implants, most commonly formed by Staphylococcus epidermidis, can promote chronic inflammation, and stimulate fibrosis and capsular contracture (Rieger et al 2013, van Heerden et al 2009, Dobke et al 1995, Netscher 2004 (Mendes et al 2008). Therefore, the possible relationship of bacterial infection and capsular contracture occurrence needs further study.…”