Recent Antibiotic Use May Increase Infection Risk for One Type of Breast Reconstruction Surgery
Microbiome imbalance may affect surgical site infection risk after tissue expander placement

For women undergoing surgery to place tissue expanders – a common technique for staged breast reconstruction – recent antibiotic use may be a risk factor for surgical site infection (SSI), reports a study in the February issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS). The journal is published in the Lippincott portfolio by Wolters Kluwer.

"In our study, patients who took antibiotics within 30 days before surgery to place tissue expanders had a four-fold increase in SSI risk – possibly due to disruption of the normal balance of protective versus pathogenic bacteria," comments Bernard T. Lee, MD, MBA, MPH, of Beth Israel Deaconess Medical Center and Harvard Medical School. "For plastic surgeons, the findings suggest the need for careful assessment of antibiotic use in patients undergoing tissue expander-based breast reconstruction."

Antibiotics may contribute to infection risk after tissue expander surgery

For many patients who have undergone mastectomy for treatment of breast cancer, tissue expander placement is performed to stretch the skin for use in breast reconstruction. Unfortunately, tissue expander surgery is associated with high rates of surgical site infection – a risk that does not seem to be reduced by antibiotics.

Antibiotics might even increase the risk of infection by disrupting the normal balance of bacteria making up the body's microbiome: a phenomenon called "dysbiosis." Previous studies have suggested that antibiotics may increase infection risk in other surgical procedures. The new study is the first to assess antibiotics as a risk factor for infection after tissue expander surgery.

Using a research database, Dr. Lee identified two groups of patients who underwent tissue expander-based breast reconstruction: an exposed group who received antibiotics within 30 days before surgery and a control group who did not. Each group included 1,383 patients. The two groups were matched to select patients with similar risk factors for infection – such as obesity, smoking or higher-stage breast cancer, among others.

'Potential detrimental consequences of preoperative antibiotic use'

Patients who received antibiotics within 30 days before tissue expander surgery were nearly four times more likely to develop SSI in the first 30 days after surgery (relative risk 3.91), compared to patients who were not exposed to antibiotics before surgery.

Patients exposed to antibiotics were also about twice as likely to experience wound-healing problems (dehiscence) or to undergo tissue expander removal. They were also more likely to receive antibiotics after surgery. All of these risks decreased gradually but remained elevated at 60 to 90 days' follow-up – perhaps reflecting restoration of the protective bacterial balance.

The findings add to previous evidence that antibiotic-related dysbiosis may increase the risk of infection after surgery. Antibiotics may promote overgrowth of infection-causing types of bacteria or the development of antibiotic-resistant bacteria.

The researchers note some limitations of their database study, including a lack of data on the reasons why exposed patients were prescribed antibiotics. Although the findings do not suggest any immediate change to clinical practice, they suggest that recent antibiotic use should be considered as a risk factor for infection in patients undergoing tissue expander-based breast reconstruction – and possibly other types of surgery as well.

"These findings underscore the potential detrimental consequences of preoperative antibiotic use, extending up to three months post-surgery, and highlight the need for careful assessment of antibiotic use before TE-based breast reconstruction," Dr. Lee and coauthors write. They highlight the need for randomized clinical trials to confirm and better understand the reported association. Future studies may also evaluate possible preventive strategies, including the use of probiotics to restore the normal balance of protective bacteria.

Plastic and Reconstructive Surgery® is published by Wolters Kluwer.

Click here to read "Recent Antibiotic Use and Surgical Site Infections in Tissue Expander–Based Breast Reconstruction: A Propensity Score–Matched Analysis"

Article: "Recent Antibiotic Use and Surgical Site Infections in Tissue Expander–Based Breast Reconstruction: A Propensity Score–Matched Analysis" (doi: 10.1097/PRS.0000000000012333)