The Association of Gram-Negative Bacteria With Decreased Salvage Rate in Infected Breast Implants

A total of 300,000 new cases of invasive breast cancer will be diagnosed in the United States this coming year accounting for >30% of all cancers diagnosed in women. Although breast-conserving surgery is on the rise, the number of BCS-eligible patients choosing mastectomy has increased and the number of breast reconstructions has increased 39% since 2000. The most common complication of implant-based reconstruction is infection.

This study utilized retrospective chart review of patients who underwent mastectomy with reconstruction requiring treatment of surgical site infection. Exclusion criteria included age younger than 18, delayed reconstruction, BMI >40, and perioperative chemoradiation. Statistical analysis was performed to test association between 2 dichotomous categorical variables: culture results and implant salvage rates.

Eighty-seven patients met criteria, undergoing washout with fluid culture. Fifty-four grew Gram-positive, 44 resulted in salvage for a salvage rate of 81.4%. Nineteen grew Gram-negative, 3 resulted in salvage for a salvage rate of 15.7%. These results are statistically significant. Fourteen cultures showed no growth, all of which were salvaged. ANOVA showed statistically significant difference among the 3 groups with P -value <0.001.

There's a clear correlation between type of bacteria cultured and salvage rates. Gram-negative infections are more likely to result in explantation within 60 days. This data may aid in the development of protocols utilizing intraoperative gram staining to guide management of these infections, ultimately helping with avoidance of additional operative procedures, which delay adjuvant chemoradiation.