Breast tissue expander-related infections: perioperative antimicrobial regimens

The rate of postmastectomy tissue expander (TE) infection remains excessively high, ranging between 2% and 24%. We hypothesized that current perioperative antimicrobial regimens utilized for breast TE reconstruction may be outdated as a result of recent changes in microflora and susceptibility patterns.

We reviewed the records of all patients who had a TE reconstructive procedure and developed a definite breast TE infection between 2003 and 2010 at MD Anderson Cancer Center. Antimicrobials were stratified into 3 groups: systemic perioperative, local irrigation, and oral immediate postoperative antimicrobials. These were considered discordant if they did not target the isolated organisms, while a breakthrough infection was defined as an infection that occurred despite concordant antimicrobial coverage.

Overall, 75 patients with a definite TE infection were identified. The most common organisms identified were methicillin-resistant Staphylococcus epidermidis (29%), methicillin-resistant Staphylococcus aureus (15%), and gram-negative rods (26%). The use of systemic perioperative antimicrobials was deemed discordant in 51% of the cases. Although 79% of the patients received broad-spectrum perioperative local antimicrobial irrigation, 63% developed a breakthrough infection. Even though 61% received oral postoperative prophylactic antimicrobials, 63% of the times they were deemed discordant.

Contrary to the proven effectiveness of a single dose of perioperative antibiotics, the common use of local antimicrobial irrigation and prolonged postoperative oral antibiotics appears to be an inadequate component of our preventive armamentarium. Also, because methicillin-resistant staphylococcal and pseudomonal infections occurred approximately 60% of the time, at institutions that have observed an increase of these organisms, it may be prudent that perioperative antimicrobials target these microorganisms.