Prolonged Antibiotic Duration is Not Associated With Reduced Surgical Site Infection After Lower Extremity Bypass Surgery.

Introduction: Surgical site infection (SSI) is among the most common complications following infrainguinal bypass surgery, despite being considered a preventable complication. The timing and selection of perioperative antibiotic prophylaxis are a key measure in SSI prevention efforts. Current practice guidelines recommend a prophylactic antibiotic duration of less than 24 h; however, there are limited data on the efficacy of prolonged antibiotic duration after lower extremity bypass (LEB) surgery.

Methods: In this national cohort study, the Vascular Quality Initiative (VQI) database was retrospectively reviewed for all infrainguinal bypass operations performed from January 2014 to December 2023. The primary outcome of interest was postoperative SSI. Perioperative antibiotics included first- and second-generation cephalosporins. Standard duration was defined as discontinuation of perioperative antibiotics within 24 h of surgical end time; and prolonged duration was defined as any extension beyond 24 h.

Results: Over the 10-y study period, 21,647 infrainguinal bypasses were performed and had complete antibiotic-related data. A total of 461 cases (2.1%) developed a postoperative SSI. All patients received preoperative antibiotics. The majority of patients (97.7%) received antibiotic within 1 h preoperatively, with no difference between patients with SSI and no SSI (97.7% versus 96.8%, P = 0.186). Prolonged antibiotics were reported in 6.6% of cases. After adjusting for patient, perioperative, and antibiotic-related factors, prolonged duration was associated with an increased SSI occurrence compared with standard duration (adjusted odds ratio [aOR] 2.01; 95% confidence interval [CI], 1.52-2.67; P < 0.001). Other risk factors included diabetes mellitus (aOR 1.24; 95% CI, 1.03-1.51; P = 0.027), end stage renal disease (ESRD) (aOR 1.86; 95% CI, 1.33-2.61; P < 0.001), and longitudinal groin incision configuration compared with a transverse incision (aOR 1.65; 95% CI, 1.23-2.20; P < 0.001). Preoperative chlorhexidine showers or wipes were associated with fewer SSI events (aOR 0.48; 95% CI, 0.29-0.78; P = 0.003).

Conclusions: In this large multi-institutional study, prolonged duration of perioperative antibiotic prophylaxis was not associated with a reduction in SSI after infrainguinal bypass surgery. These findings support antimicrobial stewardship efforts in limiting perioperative antibiotic course within 24 h of surgery.