Invivo comparison of local antibiotic application in terms of effectiveness and duration on smooth silicone, textured silicone and polyurethane implant surfaces

Augmentation mammoplasty with silicone gel implants is the most common type of plastic surgeries done worldwide. Capsular contracture is the most frequently observed postoperative complication. Capsule is in fact a natural response against a foreign body. The abnormal development of the capsule results in capsular contracture. The most frequent cause known leading to this pathologic situation is biofilm formation and the chronic subclinical infection. Moreover, in the recent years, biofilm formation and subclinical infection has also been accused of playing a role in "Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL)" development, which has been shown to develop between the capsule and the implant. The effectiveness degree and duration of local antibiotherapy application on implants with varying surface properties, which can prevent the foremost causes in capsular contracture etiology, biofilm and subclinical infection, have been researched in this study. In the study, 36 Wistar albino rats were used. Rats were divided into six groups consisting of six rats in each group. 3 pockets were created on the backs of each rat, and smooth, textured, and polyurethane surfaces were randomly placed in these pockets. Prior to application, 10⁷ Staphylococcus epidermidis was embedded in each sample. While the samples with bacterial inoculation were placed to rats in groups 1-2-3, rifampicin administration and a 5-minute standard local antibiotherapy were also performed on the rats in groups 4-5-6. Samples at groups 1-4 were extracted at the 1st hour, groups 2-5 at the 6th hour, and groups 3-6 at the 24th hour. Bacterial colony counting was then performed on the extracted samples. The bacterial load on polyurethane and textured surfaces in groups 1-2-3, which showed a continuous increase on an hourly basis, was measured above the standard value at all hours. In smooth surfaces, the bacterial load was measured below the standard value at all hours, however, the degree of colonization increased as hours passed. With regards to smooth and polyurethane surfaces, a statistically significant difference was observed at all hours, while a statistically significant difference was observed between smooth and textured surfaces in favor of the smooth surface at the 6th and 24th hours. Bacterial load of all the surfaces in groups 4-5-6 was measured below the standard value. Between the polyurethane and textured surfaces, a statistically significant difference was observed in favor of the polyurethane surface at all hours. No statistically significant difference was observed between the polyurethane and smooth surfaces at any hour even though the polyurethane surface had a lower amount of bacterial load. Between the smooth and textured surfaces, at the 6th and 24th hours, a statistically significant difference was observed in favor of smooth surfaces. When groups 4-5-6 and groups 1-2-3 were compared, a statistically significant difference in favor of groups 4-5-6 was observed on all surfaces and at all time periods excluding the 1st hour in smooth surfaces and textured surfaces. Results show that local antibiotherapy shows a significant effect in preventing biofilm formation by reducing the bacterial load. In addition, the strong initiation of the effect on the polyurethane surface observed at the 1st hour and its progressive and continuous increase towards the 24th hour gave rise to the thought that on polyurethane surfaces local antibiotherapy has a high level and long duration of effectiveness.