Use of Nipple Shields in Preventing Bacterial Contamination of Implants in Primary Breast Augmentation

Goals/Purpose: Capsular contraction (CC) is a commonly feared complication of breast augmentation. More severe grades of capsular contracture can lead to visible breast deformity or pain. Once CC occurs, there can be significant morbidity, psychological distress and cost associated with this. Understanding the causes of CC is key to prevention. Multiple risk factors have been suggested, including subclinical infection/biofilm formation, post-operative hematoma, foreign body presence in the implant pocket, breast augmentation incision placement, among others. However, it is most likely a multi-factorial process that leads to contracture formation.

Given the potential source of contamination of implants by the bacteria present within the nipple, many surgeons advocate the use of nipple shields to protect the implant from contamination during breast augmentation. This study aims to determine if nipple shields are necessary to prevent bacterial contamination of breast implants by evaluating the presence of bacteria on the nipple-areolar complex (NAC) pre-operatively and post-operatively in primary breast augmentation.

Methods/Technique: A prospective study of women undergoing primary breast augmentation at the same group practice by three separate board-certified plastic surgeons was performed. All augmentations performed were done using a dual-plane sub-muscular technique via an inframammary fold incision. A total of 18 patients and 36 breasts were included in the study. Women undergoing revision augmentation and augmentation combined with other breast procedures were excluded. The bilateral breasts and upper chest were prepped using alcohol-based skin prep solution, and this was allowed to set for 3 minutes prior to sterile draping. After sterile preparation and before placement of nipple shields, each NAC was swabbed with a separate culture swab. Sterile nipple shields were then placed. At the conclusion of the breast augmentation, nipple shields were removed and each NAC and the respective nipple shield were swabbed with a new culture swab. These four separate cultures were evaluated in laboratory for gram stain, as well as aerobic and anaerobic studies. Bacterial load was quantified as scant, light, moderate or heavy growth.

Results/Complications: A total of 36 NACs were cultured pre-operatively and immediately post-operatively after primary breast augmentation. 19% of NACs (n=7) had positive culture results either before or after surgery. 5% (n=2) of NACs had cultures become positive only after the breast augmentation; one of these showed scant growth of Propionibacterium acnes (P. acnes) and the other heavy growth of Proteus mirabilis (P. mirabilis). 14% (n=5) of NACs had positive bacterial cultures both before and after surgery; 40% (n=2) of these consistently positive NACs showed an increase in bacterial load after surgery. The most commonly isolated NAC bacterium was P. acnes, appearing on 14% (n=5) of NACs, followed by P. mirabilis which was present on 3% (n=1) of NACs. 11% (n=4) of NACs grew unspecified “skin flora”.

Conclusion: Nipple-areolar complexes are often contaminated with bacteria even after sterile preparation. In many cases, this bacterial contamination is made worse by the manipulation of the breast, such as in a breast augmentation. Nipple shields are a useful adjunct to minimizing the possibility of breast implant bacterial contamination during primary augmentation procedures, potentially lowering the risk of capsular contracture. The future direction of this study will be to compare capsular contracture rates among those surgeons who use nipple shields to those surgeons who do not use nipple shields.