Back to 2025 Resident Posters
Role Of Antibiotics Duration On Outcomes In Post-mastectomy Implant-based Breast Reconstruction
Laura Barnes, MD, Nisha Parmeshwar, MD, Jacquelyn Knox, MD, Michael Choi, MS, Aileen Gozali, BS, Merisa Piper, MD.
University of California, San Francisco, San Francisco, CA, USA.
PURPOSE:Reported infection rates after implant-based breast reconstruction vary widely, and are as high as 35%. 78% of plastic surgeons report prescribing extended antimicrobial prophylaxis (greater than 24 hours) despite growing evidence that this practice does not lead to decreased infection rates.
METHODS: We designed a two-armed randomized-controlled trial in patients undergoing mastectomy with immediate implant-based breast reconstruction. One cohort (24 hours) received standard pre-incision antibiotics and 24 hours of peri-operative antibiotics, while the other cohort (7 days) received the standard antibiotics and additionally seven days of post-operative antibiotics (cephalexin 500mg qid). Patients were followed for clinical signs of infection for at least ninety days. Data on infection rates and treatment types were collected and compared between cohorts.
RESULTS:Details on infectious outcomes are presented in Table 1. Age, BMI, comorbidities, adjuvant therapies, and reconstructive characteristics were similar between cohorts. We identified the following bacterial genera present in cultures from infected breasts:
Staphylococcus, Cutibacterium, Finegoldia, Streptococcus, Enterobacter, and
Pseudomonas. Staphylococcus was the most commonly isolated infectious agent and rates of infection were comparable between groups.
CONCLUSION:Within our expanded cohort in this randomized-controlled study, we found no significant differences in infection rates between groups of patients who received 24 hours compared to seven days of prophylactic antibiotics. We should continue to promote a more limited course of prophylactic antibiotics for this group of patients.
Table 1: Infectious Outcomes by Antibiotic Group | 7-Day Cohort (41 patients, 69 breasts) | 24-hour Cohort (43 patients, 76 breasts) | p-value |
| Any SSI | 12 breasts (17.39%) | 11 breasts (14.47%) | 0.66 |
| Ave time to develop SSI (days) | 51.75 | 51.18 | 0.37 |
| Minor SSI (oral antibiotics) | 2 breasts (2.90%) | 4 breasts (5.26%) | 0.68 |
| Major SSI (admission, IV antibiotics, return to OR) | 10 breasts (14.49%) | 7 breasts (9.21%) | 0.44 |
| SSI requiring explant | 8 breasts (11.59%) | 4 breasts (5.26%) | 0.23 |
| Recurrent SSIs | 2 breasts (2.90%) | 2 breasts (2.63%) | 1 |
| Staphylococcus positive cultures | 7 breasts (10.14%) | 5 breasts (6.58%) | 0.55 |
Back to 2025 Resident Posters
