Perioperative therapeutic antibiotics are beneficial to prevent exacerbation of limb-associated infection after bypass surgery in patients with critical limb-threatening ischemia and foot infection score of ≥1

Objective: Postoperative limb infection is associated with a poor prognosis and a low amputation-free survival rate after surgical revascularization in patients with critical limb-threatening ischemia. The Global Vascular Guidelines 2019 recommend antibiotic therapy for patients with deep space foot infection or wet gangrene; however, no study is cited as evidence for this recommendation. The present study was performed to offer new evidence supporting the use of perioperative therapeutic antibiotics in patients with critical limb-threatening ischemia (CLTI) undergoing surgical revascularization. Methods: This single-center retrospective study was performed in Kyushu University Hospital and involved patients with CLTI who underwent surgical revascularization from 2003 to 2021. Ampicillin/sulbactam and cefazolin were defined as preventive antibiotics, and other types were defined as therapeutic antibiotics. Postoperative limb-associated infection was defined as an increased foot infection (fI) score in the Wound, Ischemia, and foot Infection (WIfI) classification system after surgical revascularization. The association between perioperative antibiotic therapy and postoperative limb-associated infection was assessed. Results: Among 286 limbs of 263 patients with CLTI, 27 (9%) limbs developed postoperative limb-associated infection after surgical revascularization. The fI scores were significantly higher in the patients with than without postoperative limb-associated infection (1.0 ± 0.2 vs 0.4 ± 0.1, respectively; p = 0.0033), indicating that an fI score of ≥1 was a risk factor for postoperative limb-associated infection. Perioperative therapeutic antibiotics significantly reduced the incidence of postoperative limb-associated infection compared with preventive antibiotics (0.0% vs. 44.8%, respectively; p = 0.0028) in the patients with CLTI who had an fI score of ≥1 after bypass surgery, although perioperative therapeutic antibiotics were not effective for patients with an fI score of 0. Conclusion: Perioperative therapeutic antibiotics for patients with an fI score of ≥1 are beneficial for reducing the incidence of postoperative limb-associated infection after surgical revascularization.