The pathogenesis of fibrous capsular
contracture after augmentation
mammaplasty is still debated. One hypothesis implicates low-grade
bacterial infections as a cause. The presence of a staphylococcal biofilm in a patient with recurrent capsular
contracture was previously reported. A comparative, prospective, blinded, clinical study of implants and capsules removed from patients with or without significant capsular
contracture was conducted to investigate the association of biofilm contamination,
breast implants, and capsular
contracture.
Capsule and implant samples obtained during explantation were tested by routine microbiological culture, sensitive broth culture (after maceration and sonication), and scanning electron microscopy. Clinical parameters were correlated with microbiological findings. A total of 48 implant and/or
capsule samples were obtained from 27 breasts during a 22-month period. Of the 27 breasts, 19 exhibited significant
contracture (Baker grade III/IV). The mean duration of implantation was 9.2 years (range, 0.4 to 26.0 years). Routine swab cultures obtained at the time of explantation were negative for bacterial growth for all samples. The sensitive broth culture technique yielded 24 positive samples (50 percent, n = 48). An analysis of capsules demonstrated that 17 of 19 samples obtained from patients with significant
contracture were positive, compared with only one of eight samples obtained from patients with minimal or no
contracture (p = 0.0006). Fourteen of the 17 positive cultures from significantly contracted breasts yielded
coagulase-negative staphylococci, mainly, species of the Staphylococcus epidermidis group. The presence of
coagulase-negative staphylococci was also significantly associated with capsular
contracture (p = 0.01). There was no significant difference in the frequency of culture positivity for saline versus
silicone implants (p = 0.885). Scanning electron microscopy confirmed the presence of extensive biofilm on implants and within capsules.Biofilm, in particular, S. epidermidis biofilm, was detected for a significant proportion of patients with capsular
contracture. This implicates biofilm disease in the pathogenesis of
contracture, and strategies for its prevention should be explored.