Efficacy of antiseptic impregnation of aortic endografts with rifampicin compared to silver against in vitro contamination with four bacteria that frequently cause vascular graft infections

Abstract

Objective This in vitro study investigates the antimicrobial efficacy of impregnation of commercially available aortic endografts (EG) with rifampicin (RIF) and nanocolloidal silver. Methods Endografts were flushed with 50 mL of RIF 600 mg, 70 mL of a silver-based aqueous solution (AG), or 50 mL of phosphate-buffered saline (PBS) over 15 minutes. Endografts were then retrieved from the sheath and cut in 1 × 1 cm sized graft units (n = 80 of each impregnation), which were then incubated for 1 hour separately with inoculates containing 10 6 or 10 3 bacteria per milliliter (bact/mL) of each of the following bacteria: Staphylococcus epidermidis, Escherichia coli, multisensitive Staphylococcus aureus , and Pseudomonas aeruginosa . After sonication of the graft units, bacterial counts were measured by plating out twice the sonication solution on Mueller-Hinton plates. Results RIF showed a statistically significant decrease of colony forming units per milliliter for all four bacterial strains in both concentrations compared with PBS and AG, except for 10 3 bact/mL of E coli . AG showed a significant decrease of colony forming units per milliliter compared with PBS only for 10 6 bact/mL of E coli and was statistically significantly inferior to RIF for all four bacterial strains in both concentrations with the exception of E coli at a concentration of 10 3 bact/mL. Conclusions This in vitro study demonstrated infectivity resistance of aortic EG after flushing with RIF. Moreover, the feasibility of flushing aortic EG with a new silver-based agent could be demonstrated, but without statistically significant antimicrobial efficacy compared with native EG.

Silver Ion Decreases Foreign Body Reaction and Venous Neointimal Hyperplasia through the Inhibition of Interleukin-33 Expression

“…The cell population within the scaffold 1 week after implantation comprised polymorphonuclear cells, macrophages, and eosinophils, which result from the foreign body reaction. Although more than hundreds of patients received silver-coated vascular grafts, no studies have reported on neointima change after silver-coated vascular graft implantation [5, 36]. In the rat IVC venoplasty model used in this study, a significantly thinner neointima was observed in the silver patch group.…”

“…Silver is highly effective in the treatment of infections, and grafts simply flushed with a silver-based aqueous solution over 15 min have also exhibited antimicrobial efficacy [5]. Many clinical and basic studies have examined the anti-infection effect of silver; however, few studies have focused on tissue reaction or neointimal hyperplasia after silver-coated graft implantation.…”

Aortic Endograft Infection: Diagnosis and Management

“…Antimicrobial-treated prosthetic grafts have been used to reduce the reinfection rate of prosthetic grafts in infected fields [ 44 , 45 ]. Antibiotic (e.g., rifampicin, vancomycin, and daptomycin)-soaked prosthetic grafts and silver-coated polyester grafts (InterGard Silver Prosthesis; Getinge) are commercially available.…”

Use of a Silver-Impregnated Vascular Graft: Single-Center Experience

“…Therefore, this is a completely different mechanism compared to the release of antibiotics from antibiotic-bound grafts [20]. The microbicidal function of silver should therefore significantly increase resistance to infection [15,21], but recently published studies are also controversial [22,23]. The aim of this work is to present the results of an observational retrospective clinical study conducted in a single center using silver-impregnated vascular grafts in various indications.…”