Prevention of primary vascular graft infection with silver-coated polyester graft in a porcine model.
ABSTRACT To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model.
Eighty-four pigs were randomly selected 1:1 to receive a silver-coated or non-silver-coated 8-mm-wide polyester graft implanted end-to-end in the infrarenal aorta. At the end of implantation, 10(6) colony forming units (CFUs) S. aureus in 0.3ml suspension were inoculated directly on the graft surface. Blood samples assayed for white blood corpuscles (WBCs) and C-reactive protein (CRP) were taken before implantation and on the postoperative days 2, 5, 7, 11 and 14. Two weeks after implantation, the perigraft swabs were analysed for S. aureus or contaminants. CFUs of S. aureus were quantified and logarithmised. Student's t-tests, repeated measurement analysis of variance (ANOVA) and chi-square test were employed to compare the two grafts.
All pigs developed graft infection. There were no statistically significant differences between the silver-coated and non-silver-coated grafts in the quantity of S. aureus, macroscopic signs of infection and postoperative changes in the temperature, WBC and CRP.
Silver-coated polyester grafts failed to prevent graft infections after inoculation with 10(6)S. aureus in 0.3ml suspension in a porcine model.
Article: Prosthetic vascular graft infection.[show abstract] [hide abstract]
ABSTRACT: The aetiology, diagnosis and management of prosthetic vascular graft infection are reviewed. The importance of contamination at the time of surgery as the crucial aetiological factor is highlighted. Staphylococcus epidermidis is the causative organism in over 50 per cent of cases and the reasons for this are explored. Sound surgical technique, use of prophylactic antibiotics and the avoidance of a groin incision are emphasized as the most important factors in prevention of graft infection. Difficulties of diagnosis are highlighted and the diagnostic role of various imaging methods is assessed. Graft excision with extra-anatomic revascularization is presented as the conventional surgical solution, while the roles of less radical surgical solutions and non-operative management are discussed.British Journal of Surgery 01/1993; 79(12):1262-7. · 4.84 Impact Factor
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ABSTRACT: Despite the use of prophylactic antibiotics in vascular surgery, prosthetic infection rate remains 2-5%. Antibiotics bound to vascular prostheses can control experimentally induced infection but prolonged antibacterial activity has not been achieved. This study evaluates the in vivo efficacy and antibiotic retention of an easily prepared silver-antibiotic prosthesis. Prostheses were prepared by combining silver with oxacillin or amikacin using an organic solvent. After evaporation of the solvent, the graft was left impregnated with the antibiotic complex. In vivo retention studies were performed by implanting PTFE 110Ag-oxacillin prostheses in four canine abdominal aortas. When prostheses were explanted at 1 week, mean antibiotic retention was found to be 20% of original activity, higher than the mean inhibitory concentration for Staphylococcus aureus. In three groups of five dogs, 20 X 7-mm prostheses of PTFE alone, PTFE silver-oxacillin, or PTFE silver-amikacin were implanted in the abdominal aorta and the grafts were inoculated with 10(7) S. aureus of a known bacteriophage type, in a closed retroperitoneal pocket. The animals were sacrificed at 1 week and the prostheses were excised for quantitative bacterial culture. PFTE silver-oxacillin, and PTFE silver-amikacin prostheses had 1.7 X 10(2) and 2.0 X 10(2) colonies, respectively, significantly less (P less than 0.05) than controls (1.3 X 10(6) colonies). These data suggest that antibiotic prostheses can be easily prepared without binding agents. They retain the bound antibiotic for a prolonged period and are effective in reducing graft infection in a stringent direct contamination model.Journal of Surgical Research 02/1988; 44(1):1-7. · 2.02 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the ability of vascular polyester grafts with antibacterial properties to resist colonization following surface contamination by methicillin-resistant Staphylococcus aureus (MRSA) in an experimental canine model or aortic graft infection. Twenty-four pathogen-free dogs underwent replacement of the infrarenal aorta with either a rifampin-soaked (30 mg/mL) or silver-impregnated (Ag-acetate) woven polyester graft. Following implantation, the external graft surface was inoculated with 2 mL of 10(7) colony-forming units/mL (CFU) of MRSA. Preoperative antibiotic prophylaxis consisted of a single intravenous dose of 500 mg of sodium cefazolin. Four grafts of each type were explanted at 3, 7, and 14 days after implantation. Quantitative cultures (CFU/specimen) of perigraft fluid (1 mL), graft material (1 cm segment), and adjacent aorta (1 cm segment) were performed. Differences between grafts are expressed as % mean log reduction in recoverable CFU compared to the inoculation solution concentration of 10(7) CFUs. At 3 days, explanted rifampin-soaked grafts exhibited no MRSA growth (4 of 4 grafts) and a > or =97% mean log reduction of MRSA CFUs from the adjacent aorta and perigraft fluid (PGF). At 3 days, all silver-bonded grafts exhibited signs of infection and a mean log CFU reduction of MRSA ranging from 68% (absolute range 10(1)-10(3) recoverable CFU) for the graft, 79% (absolute range 10(1)-10(3) recoverable CFU) for the aorta, and 86% (absolute range 10(1)-10(4) recoverable CFU) for PGF. The 7-day rifampin group had an average log reduction in MRSA CFU of 72% (graft), 58% (PGF), 75% (aorta). Quantitative cultures of 14-day rifampin grafted demonstrated continued bacterial growth suppression with mean MRSA CFU log reductions of 82%, graft; 72%, PGF; 89%, aorta. Silver-bonded grafts demonstrated <50% mean CFU reduction in MRSA growth at 7 days (absolute range 10(5)-10(7) recoverable CFU) and 14 days (absolute range 10(3)-10(7) recoverable CFU). No animal died from sepsis or anastomotic hemorrhage. Neither rifampin- nor silver-bonded grafts demonstrated prolonged resistance to surface MRSA contamination. Rifampin-soaked polyester grafts exhibited a marked but transient resistance MRSA colonization likely the result of high antibiotic concentration in the perigraft tissue. While both types of grafts failed to eradicate the MRSA infection future research with silver-bonded grafts that have an additional antibiotic attached may have a place in the treatment of MRSA infection.Vascular and Endovascular Surgery 01/2005; 39(5):411-20. · 0.88 Impact Factor