Experimentelle untersuchung der effizienz von silberbeschichteten gefäß-dacronprothesen nach subcutaner implantation im standardisierten in vivo-infektionsmodell

It was the aim of the study to examine the efficacy of silver coated prostheses in comparison to Rifampin impregnated prostheses in the prevention of vascular graft infections. Material and methods: 24 C3H/HcN mice with a bodyweight between 24 and 27 grams were assigned to four different groups. Group I: control gel-sealed Dacron graft (Uni-Graft®DV) (6), group II: gel-sealed Dacron graft (Uni-Graft®DV) contaminated locally with 2 × 10⁷ CFU/0.2ml Staphylococcus aureus ATCC25923 (6), group III: silver prosthesis (Intergard® Silver) contaminated locally with 2 × 10⁷ CFU/0.2 ml Staphylococcus aureus ATCC 25923 (6), group IV: Rifampin impregnated prosthesis contaminated locally with 2 × 10⁷ CFU/0.2 ml Staphylococcus aureus ATCC 25923 (6). 14 days after primary operation all animals were euthanized and the grafts harvested. Specimens were examined for signs of infections by histology and microbiology. Results: At termination of the trial on day 14 none of the grafts of group 1 were contamined. 6 out of 6 grafts in group 11, 6 out of 6 in group III and 1 out of 6 in group IV presented with infected grafts. The use of the antimicrobial Rifampin could significantly prevent infection after bacterial challenge in group IV. Conclusion: The silver protected prosthesis (Intergard®Silver) seems to be not effective in protecting vascular infection in vivo. However, the Rifampin group showed excellent results. In conclusion Rifampin bonded gelatin-sealed Dacron grafts are significantly more resistant to bacteremic infection than are silver/collagen-coated Dacron grafts.