While the causes of capsular contracture have not yet been elucidated, subclinical infection is a likely culprit. We hypothesized that the source of this contamination is endogenous breast bacteria, likely originating in the ducts themselves rather than on the skin. The purpose of this study was to describe the nature of endogenous breast bacteria, and to determine whether the concentration of it differs significantly among the three most commonly used incision sites for breast implant placement.
Methods/Technique:
We performed an IRB approved analysis of endogenous breast bacteria. Patients presenting for routine reduction mammaplasty were recruited as study subjects. Tissue samples were taken intra-operatively from the peri-areolar, infra-mammary, and axillary regions of each breast. Specimens were then processed in the microbiology laboratory and quantitative bacterial counts were obtained. 18 breasts were sampled, for a total of 54 specimens.
Results/Complications:
Of the 18 breasts sampled, 7 yielded positive culture results, for a 38% positive culture rate. There was a significant difference in positive culture rate between the axillary region and the other two sites. For all seven patients with positive cultures, the quantitative counts were highest at the peri-areolar region.
Organisms identified in this study included various species of Staphylococcus, with Staphylococcus epidermidis being the most common.
Conclusion:
The breast harbors significant endogenous bacteria which can become the source of spontaneous or postoperative infection. Positive intra-operative cultures with high quantitative counts suggest that breast tissue harbors more bacteria than normal skin flora. Routine peri-operative antibiotic prophylaxis may be suboptimal for the prevention of foreign body seeding in this setting. Furthermore, bacterial concentrations are highest in areas with the most ductal tissue, namely the peri-areolar region. These findings may be helpful when considering what incision to use for augmentation mammaplasty.