Effectiveness of single vs multiple doses of prophylactic intravenous antibiotics in implant-based breast reconstruction : A randomized clinical trial

Importance: Multiple-dose antibiotic prophylaxis is widely used to prevent infection after implant-based breast reconstruction despite the lack of high-level evidence regarding its clinical benefit. Objective: To determine whether multiple-dose antibiotic prophylaxis is superior to single-dose antibiotic prophylaxis in preventing surgical site infection (SSI) after implant-based breast reconstruction. Design, Setting, and Participants: This prospective, multicenter, randomized clinical superiority trial was conducted at 7 hospitals (8 departments) in Sweden from April 25, 2013, to October 31, 2018. Eligible participants were women aged 18 years or older who were planned to undergo immediate or delayed implant-based breast reconstruction. Follow-up time was 12 months. Data analysis was performed from May to October 2021. Interventions: Multiple-dose intravenous antibiotic prophylaxis extending over 24 hours following surgery, compared with single-dose intravenous antibiotic. The first-choice drug was cloxacillin (2 g per dose). Clindamycin was used (600 mg per dose) for patients with penicillin allergy. Main Outcomes and Measures: The primary outcome was SSI leading to surgical removal of the implant within 6 months after surgery. Secondary outcomes were the rate of SSIs necessitating readmission and administration of intravenous antibiotics, and clinically suspected SSIs not necessitating readmission but oral antibiotics. Results: A total of 711 women were assessed for eligibility, and 698 were randomized (345 to single-dose and 353 to multiple-dose antibiotics). The median (range) age was 47 (19-78) years for those in the multiple-dose group and 46 (25-76) years for those in the single-dose group. The median (range) body mass index was 23 (18-38) for the single-dose group and 23 (17-37) for the multiple-dose group. Within 6 months of follow-up, 30 patients (4.3%) had their implant removed because of SSI. Readmission for intravenous antibiotics because of SSI occurr