PREVENTION OF GRAFT INFECTION BY BONDING OF GENTAMICIN TO DACRON PROSTHESES

To increase the efficacy of perioperative antibiotic prophylaxis in vascular surgery an experimental study including topical application of the gentamicin derivative EMD 46/217 and fibrin sealant as antibiotic carrier to Dacron prostheses was initiated. In vitro treatment of Dacron with gentamicin and fibrin was followed by constant antibiotic release for 3 weeks. In a subsequent animal study Dacron grafts were implanted in the aorta of 10 pigs after direct contamination with Staphylococcus aureus solution. One graft was pretreated with the antibiotic/fibrin compound, a second with the antibiotic alone. Grafts 3 (no pretreatment) and 4 (fibrin alone) served as controls. After 1 week the grafts and their corresponding implantation sites were excised for measurement of antibiotic content and for culture. The antibiotic content of grafts with the antibiotic/fibrin compound was 25.0 +/- 7.2-mu-g/gm wet weight, whereas Dacron pretreated with the antibiotic alone contained no measurable drug amounts except for one specimen (0.5-mu-g/gm) (antibiotic/fibrin vs antibiotic, p < .0005). The corresponding implantation sites to antibiotic/fibrin grafts contained 1.07 +/- 0.54-mu-g/gm antibiotic, whereas in only 2/10 implantation sites of antibiotic grafts low antibiotic levels were found (0.05 and 0.2-mu-g/gm) (antibiotic/fibrin vs antibiotic, p < 0.005). All control grafts and 9/10 antibiotic grafts were infected. By contrast, only five were contaminated, and 5 of 10 remained sterile after culture (antibiotic/fibrin vs antibiotic, p < 0.05). This finding correlates with the antibiotic content in the Dacron. It is concluded that pretreatment of prosthetic Dacron grafts with the antibiotic/fibrin compound results in binding of sufficient amounts of antibiotic for at least 1 week. This procedure can serve as a prophylactic tool against perioperative vascular graft infection.