Antimicrobial-bonded graft patency in the setting of a polymicrobial infection in swine (Sus scrofa).

BACKGROUND: Polytetrafluoroethylene (PTFE) and Dacron are commonly used as arterial conduits in vascular trauma or infection when vein interposition graft may not be available. This study used a previously validated large animal model of polymicrobial infection to assess the patency and infectious resistance of a novel, antibiotic-impregnated graft material compared with PTFE and Dacron.

METHODS: Forty-eight animals were placed into five groups for a 21-day survival period. A 6-mm PTFE, Dacron, or antimicrobial-bonded graft was used to replace the iliac artery and then inoculated with 1 × 107 colonies/mL of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. Native vessels with and without contamination served as control groups. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiologic measurements, blood cultures, laboratory data, and histopathology.

RESULTS: At 21 days, 50% of PTFE, 62.5% of Dacron, and 100% of the antimicrobial-bonded grafts remained patent (P = .04). PTFE and Dacron had an equivalent number of overall infections, 87.5% and 75%, respectively (P = 1.0). There was no significant difference of infectious organisms between standard materials. The infection rate of the antimicrobial-bonded graft (25%) was significantly less than that of both PTFE and Dacron (P < .01), and all of these infections were secondary to P. aeruginosa. Clinical data did not vary significantly between groups. There were no mortalities in the protocol secondary to graft blowout or sepsis.

CONCLUSIONS: The antimicrobial-bonded graft material outperformed standard PTFE and Dacron in the setting of polymicrobial infection with regard to graft patency and infection. The novel prosthetic material appears to be resistant to infection with S. aureus and to limit the growth of P. aeruginosa. Additional studies are recommended to explore the role of this antibiotic-bonded graft for use in the setting of vascular infection or trauma.