Evaluating effectiveness of antibiotic polymethylmethacrylate beads in achieving wound sterilization and graft preservation in patients with early and late vascular graft infections

Abstract

The objective of the study was to evaluate the effectiveness of antibiotic-based polymethylmethacrylate (ab-PMMA) beads in achieving wound sterilization and graft preservation in patients with vascular graft infections. We reviewed 31 patients treated for 37 graft infections over the past 5 years using ab-PMMA beads in a single institution. All patients were started on broad-spectrum antibiotics and later switched to targeted therapy based on intraoperative cultures for at least 6 weeks. All patients underwent multiple planned wound explorations, debridements and washouts. Cultures were obtained each time. Decision to do formal closure depended on culture results and wound appearance. All wounds were closed with a muscle flap. The endpoints included wound sterilization, limb salvage, recurrence of infection, and graft preservation. A total of 19 different organisms were cultured, and 48.6% of cases were polymicrobial, thereby accounting for a total of 60 isolates. The majority (n = 27) received a mix of tobramycin/vancomycin PMMA beads; vancomycin beads (n = 5); tobramycin beads (n = 1); and gentamicin/vancomycin beads (n = 4). Wound sterilization based on cultures was achieved in 32 of 34 wounds (94.1%). Of the cases, 5 underwent early graft removal, 3 with immediate reconstruction, and 1 case underwent a major amputation (2.7 %). Graft preservation was attempted in 32 cases (86.5%). No death occurred within 30 days. Limb salvage was achieved in 28 of the 32 preserved graft cases (87.5%) at a mean follow-up of 26 months (6 to 51 months). The long-term limb salvage rate for the cohort was 86.5%. Of the patients, 4 presented with recurrent graft infection and occlusion, causing acute limb ischemia and resulting in major amputation. The reinfection rate was 12.5% in the graft-preservation group and 11.4% in both the graft-preserved and the in situ replacement groups. Sterilization of graft infection can be achieved with ab-PMMA beads followed by closure with muscle flap, resulting in an acceptable limb-salvage rate despite virulent or polymicrobial graft infection.