Microbiology of breast tissue expanders

Introduction
Infection is one of the most common complications of breast reconstruction. The presence of bacterial biofilm on the implant surface does not always manifest itself clinically as an infection. Still little is known about the factors that trigger the transition from a normal to a pathological state.

The aim of study
To examine a specific profile of microorganisms associated with a tissue expander, and to ascertain whether the collection of intraoperative bacteriological swabs constitutes a significant predictive factor.

Material and methods
A 2-centre review of outcomes of breast cancer patients who underwent immediate 2-stage expander-implant breast reconstruction between June 2020 and September 2021 was conducted. During this period, 68 replacements of expanders with implants from 56 women were performed. A bacteriological swab was taken from each expander compartment, and microbiological culture was performed. Patients’ characteristics were taken into consideration.

Results
Tissue expanders were implanted from 2 to 26 months. Seven patients had an emergency expander removed due to infection or damage to the device. Out of all 56 patients evaluated, 47 had a negative and 9 had a positive culture, 1 in both breasts. The results did not correlate closely with the clinical status.

Conclusions
Bacteria colonize both clinically normal and infected expanders. It is difficult to determine the specific flora associated with the pocket after expander-based reconstruction, and taking a bacteriological swab each time as a standard does not influence the success of treatment.