Tobramycin-adhesive in preventing and treating PTFE vascular graft infections

The present study was designed to determine the effectiveness of N-butyl-2-cyanoacrylate as a vehicle to deliver antibiotics locally to contaminated vascular graft sites and to grafts with established infections. Phase I--Contaminated wound model: Sixteen dogs had a 1-cm section of infrarenal aorta replaced with a PTFE graft. Prior to placement, the graft was immersed in solutions of Escherichia coli 3 X 10(8) CFU/ml and then Staphylococcus aureus 3 X 10(8) CFU/ml. After anastomosis, 1 cc of each solution was placed directly over the graft. Eleven dogs served as controls and 5 as treatment dogs. Parenteral cefonecid was given preoperatively and daily until sacrifice. Treatment animals had the anastomoses and graft sealed with a suspension of N-butyl-2-cyanoacrylate and 1.2 g tobramycin powder (antibiotic glue, ANGL) after contamination. All dogs were reoperated on the third postoperative day.

Eleven of 11 control dogs had positive cultures for S. aureus and 9 of 11 had positive cultures for E. coli. Seven of 11 had pseudoaneurysms, 1 exsanguinated. None of the 4 treatment dogs had positive cultures (P = 0.0002), pseudo-aneurysms (P = 0.017), or local signs of sepsis. Phase II--Infected graft model: The 10 surviving infected control dogs served as the established graft infection model. These dogs were randomized into two groups; Group 1 control (N = 5) had the graft replaced; Group 2 treatment (N = 5) had the graft replaced and ANGL treatment. Dogs were sacrificed after 2 weeks.

Graft cultures were positive in all 4 control dogs and negative in the 4 treatment dogs (P = 0.005). One dog in each group was eliminated secondary to failure to obtain graft culture. The data show that ANGL can be effective in the prevention and treatment of prosthetic graft infection.