Infection in breast implants – Authors' reply

Post-Mastectomy Surgical Pocket Irrigation With Triple Antibiotic Solution vs Chlorhexidine Gluconate: A Randomized Controlled Trial Assessing Surgical Site Infections in Immediate Tissue Expander Breast Reconstruction

BACKGROUND

Post-mastectomy pocket irrigation solution choice is debated and primarily surgeon dependent. We compare triple antibiotic solution (TAS) with 0.05% chlorhexidine gluconate (CHG).

OBJECTIVES

The purpose of this study was to determine surgical site infection (SSI) rates after utilizing TAS vs CHG for breast pocket irrigation in immediate tissue expander (TE) breast reconstruction.

METHODS

A prospective, blinded, randomized controlled trial was performed in patients (18-81 years old) who underwent bilateral mastectomy with TE reconstruction. In each patient, 1 mastectomy pocket was randomized to TAS and the other to CHG. Both the TE and the pocket were irrigated in the respective solution. The primary outcome was the incidence of SSI. Secondary outcomes were rates of mastectomy flap necrosis, hematoma, and seroma.

RESULTS

A total of 88 patients who underwent bilateral immediate breast reconstruction were enrolled. Demographic and operative characteristics were equivalent because each patient served as their own control. Between the TAS and CHG groups, the incidence of SSI did not differ (5 [4.5%] vs 7 [8.0%], P = 0.35), including minor infections (2 [2.3%] vs 1 [1.1%], P = 0.56), major infections (2 [2.3%] vs 6 [6.8%], P = 0.15), and those resulting in explantation (2 [2.3%] vs 5 [4.5%], P = 0.25). Necrosis, hematoma, or seroma formation also did not differ. No patients who developed SSI received radiation.

CONCLUSIONS

This study does not demonstrate a statistically significant difference in SSI between TAS and CHG irrigation, though TAS approached statistical significance for lower rates of infectious complications.

LEVEL OF EVIDENCE: 2

Early Expander-to-Implant Exchange after Postmastectomy Reconstruction Reduces Rates of Subsequent Major Infectious Complications

Major infectious complications after implant-based postmastectomy reconstruction commonly occur late (>30 days postoperative). We set out to determine if early expander-to-implant exchange (3-6 weeks after tissue expander placement) reduced rates of subsequent major infectious complications.

METHODS

We retrospectively examined patients after mastectomy and tissue expander reconstruction followed by early expander-to-implant exchange versus exchange at least 6 months after initial tissue expander placement (the control group). Multivariate logistic regression analysis was performed to determine whether the timing of implant exchange independently predicted major infectious complications occurring more than 30 days after initial tissue expander placement after adjusting for differences in patient variables between groups.

RESULTS

In total, 252 consecutive patients (430 breasts) between August 2014 and October 2019 were included. While the rates of major early infectious complications after mastectomy and tissue expander placement were similar between the groups, the control group had more subsequent major infectious complications during the reconstructive process [9.8% (n = 22) versus 1.9% (n = 4), P < 0.001].

CONCLUSIONS

Early implant exchange results in a reduced subsequent rate of major infectious complications. This protocol reduces the window of time for late infectious complications to develop by proceeding with exchange within 6 weeks of tissue expander placement instead of the standard 6 months, which is common practice. We hypothesize that early exchange allows for washout of the mastectomy cavity, eliminating indolent bacterial contamination that could have subsequently manifested as a late infection. This protocol also obviates the need to operate on patients that undergo post-mastectomy radiotherapy, which also reduces reconstructive failure rates.

The Evolution of Breast Implant Infections: Serratia marcescens Is an Emerging Pathogen in Implant-Based Breast Reconstruction

The flora of implant-based breast infections has changed over the last decade, including at our institution. A 10-year retrospective chart review was performed on 561 implant-based breast reconstructions in 378 patients performed by a single surgeon in an academic university hospital setting. Thirty-two breast infections requiring explantation of the implants occurred during those 10 years. During that time frame, a new pre- and peri-operative protocol was implemented in an effort to diminish infections. We believe that this protocol played a major role in the evolution of changing breast periprosthetic infection flora, from nearly one-third being gram-negative infections to 100% being gram-negative infections. Gram-negative antibiotic coverage should be considered in light of these evolving trends to prevent infections particularly with Serratia marcescens. This may be especially important in patients with BRCA1/2 or ATM mutations. Diabetic patients are more likely to develop Methicillin-resistant Staphylococcus aureus (MRSA) infections and preoperative MRSA decolonization is essential in these patients. Many patients have late-onset breast periprosthetic infection, the majority of which occurred after 30 days. Regular follow-up and patient education is important to provide timely treatment.