Infections after Mastectomy and Tissue Expander Placement: A Multivariate Regression Analysis

What did we catch? Predictors of infection after tissue expander-based breast reconstruction in a safety-net system

BACKGROUND

Infection is a common complication following tissue expander (TE)-based breast reconstruction. Few studies have examined risk factors specifically in the unique populations encountered at safety-net hospitals. The purpose of this study was to identify predictors of TE infection at Harris Health safety-net hospitals, which serve the third most populous county in the United States.

METHODS

A retrospective review was performed to evaluate women over the age of 18 years who underwent TE placement at two safety-net hospitals from October 2015 to November 2022. Demographic information, medical history, operative details, and postoperative course were recorded for each individual TE. The primary outcome was TE infection, for which univariate and multivariate analysis was conducted. The secondary outcome was the time to onset of TE infection, for which a Kaplan-Meier analysis was undertaken.

RESULTS

There were 279 patients, totaling 372 breasts, meeting the inclusion criteria. The TE infection rate was 23%. Increased body mass index (BMI), diabetes, use of acellular dermal matrix (ADM), and prolonged surgical drain use were all significantly associated with TE infection in univariate and multivariate analysis. Similarly, BMI ≥30 kg/m2, diabetes, and ADM use were also associated with earlier onset of TE infection.

CONCLUSIONS

This study demonstrated similar TE infection rates at our safety-net hospitals compared with previously reported literature. To optimize the quality of care for patients in safety-net institutions, these risk factors must be addressed in the context of the unique challenges encountered in these settings.

Reinforcement of a Subcutaneous Pocket for Implantable Cardioverter Defibrillator Insertion Using Acellular Dermal Matrix: A Case Report

Pediatric patients who undergo implant insertion into the chest wall face a high risk of implant exposure to the external environment. Five months after an 8-year-old boy underwent implantable cardioverter-defibrillator (ICD) implantation in a subcutaneous pocket in the left anterolateral chest wall to manage long QT syndrome, ICD replacement became necessary owing to exposure risk from distal and lateral thinning of the ICD pocket. Pocket rupture and exposure would increase the risk of infection; therefore, we performed ICD removal and primary pocket closure. Two weeks later, a new suprafascial pocket was created, an acellular dermal matrix (ADM) was attached to the inner wall to prevent ICD protrusion, and a new ICD was inserted. One year postoperatively, the ADM was engrafted, and no complications were observed. A thin subcutaneous layer increases the risk of ICD implantation complications. Inner wall strengthening with an ADM can help prevent pocket rupture.

Efficacy of Prophylactic Postoperative Antibiotics in Tissue Expander-Based Breast Reconstruction: A Propensity Score-Matched Analysis

BACKGROUND

Conflicting evidence exists regarding the utility of prophylactic postoperative antibiotics in tissue expander (TE)-based breast reconstruction. This study evaluated the risk of surgical-site infection between patients receiving 24 hours of perioperative antibiotics alone versus prolonged postoperative antibiotics within a propensity score-matched cohort.

METHODS

Patients undergoing TE-based breast reconstruction receiving 24 hours of perioperative antibiotics alone were propensity score-matched 1:3 to patients receiving postoperative antibiotics based on demographics, comorbidities, and treatment factors. Incidence of surgical-site infection was compared based on duration of antibiotic prophylaxis.

RESULTS

Of a total of 431 patients undergoing TE-based breast reconstruction, postoperative antibiotics were prescribed in 77.2%. Within this cohort, 348 were included for propensity matching (no antibiotics, 87 patients; antibiotics, 261 patients). After propensity score matching, there was no significant difference in incidence of infection requiring intravenous (no antibiotics, 6.9%; antibiotics, 4.6%; P = 0.35) or oral antibiotics (no antibiotics, 11.5%; antibiotics, 16.1%; P = 0.16). In addition, rates of unplanned reoperation ( P = 0.88) and 30-day readmission ( P = 0.19) were similar. After multivariate adjustment, prescription of postoperative antibiotics was not associated with a reduction in surgical-site infection (OR, 0.5; 95% CI, -0.3 to 1.3; P = 0.23).

CONCLUSIONS

Within a propensity score-matched cohort accounting for patient comorbidities and receipt of adjuvant therapies, prescription of postoperative antibiotics after TE-based breast reconstruction conferred no improvement in rates of TE infection, reoperation, or unplanned health care use. These data underscore the need for multicenter randomized trials on the utility of antibiotic prophylaxis in TE-based breast reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

The Impact of Postoperative Antibiotic and Duration After Implant-Based Breast Reconstruction on Resistance Among Cultured Species

BACKGROUND

There is a growing presence of literature within plastic surgery that establishes best practice for postoperative antibiotics after implant-based breast reconstruction (IBBR), although it has not been widely adopted or translated into clinical practice. This study aims to determine how antibiotic and duration affects patient outcomes. We hypothesize that IBBR patients who receive a longer duration of postoperative antibiotics will demonstrate higher rates of antibiotic resistance as compared with the institutional antibiogram.

METHODS

A retrospective chart review included patients who underwent IBBR between 2015 and 2020 at a single institution. Variables of interest included patient demographics, comorbidities, surgical techniques, infectious complications, and antibiograms. Groups were classified by antibiotic (cephalexin, clindamycin, or trimethoprim/sulfamethoxazole) and duration (≤7 days, 8-14 days, and >14 days).

RESULTS

There were a total of 70 patients who experienced infections included in this study. Onset of infection did not differ based on antibiotic during either device implantation (postexpander P = 0.391; postimplant P = 0.234). Antibiotic and duration did not have an established relationship with explantation rate either (P = 0.154). In patients who had Staphylococcus aureus isolated, there was significantly increased resistance to clindamycin when compared with the institutional antibiogram (sensitivities of 43% and 68%, respectively).

CONCLUSIONS

Neither antibiotic nor duration displayed a difference in overall patient outcomes, including explantation rates. In this cohort, S. aureus strains isolated in association with IBBR infections demonstrated a higher level of resistance to clindamycin compared with strains isolated and tested within the broader institution.