Antibiotics and Surgical Site Infection in Expander-Based Breast Reconstruction Trial (ASSERT)

Area of Science:

• Plastic Surgery
• Infectious Disease Prevention
• Clinical Trials

Background:

• Prophylactic antibiotic use after postmastectomy tissue expander breast reconstruction (TE-BR) lacks standardized guidelines.
• The Centers for Disease Control and Prevention (CDC) recommends a single preoperative antibiotic dose for certain surgical procedures.
• Current practices for antibiotic prophylaxis in TE-BR are highly variable.

Purpose of the Study:

• To investigate if a single preoperative dose (SPD) of antibiotics is non-inferior to a 7-day postoperative (WPO) prophylactic antibiotic regimen.
• To assess the efficacy of SPD versus WPO in preventing surgical site infections (SSI) in immediate TE-BR.
• To compare unplanned tissue expander removal, hospitalization, and return to operating room rates between the two antibiotic regimens.

Main Methods:

• A multi-institutional, prospective, randomized controlled trial (RCT) involving women aged 18 years or older undergoing immediate TE-BR.
• Participants were randomized to receive either a single preoperative dose (SPD) or a 7-day postoperative (WPO) course of prophylactic antibiotics.
• The primary outcome was SSI, defined by CDC guidelines within 30 days post-surgery, using a non-inferiority design with a 6% margin.

Main Results:

• The SSI rate was 17% in the SPD group compared to 11% in the WPO group (p=0.496), indicating non-inferiority was not significantly demonstrated.
• Both regimens were comparable regarding unplanned tissue expander removal for infection, hospitalization rates, and return to the operating room within 30 days.
• 235 women were enrolled across five centers, with 102 in the SPD arm and 112 in the WPO arm.

Conclusions:

• The study did not definitively establish that a single preoperative antibiotic dose is non-inferior to a 7-day postoperative regimen for preventing SSI in immediate TE-BR.
• No significant evidence supported the superiority of the 7-day postoperative regimen over the single preoperative dose.
• These findings have important implications for antibiotic practice management in TE-BR procedures.