PS224. Mouse Arteriovenous Fistula Recapitulates the Course of Human Fistula Maturation

Methods: The 2-hour and 24-hour attachment of Staphylococcus aureus TCH1516 and Pseudomonas aeruginosa PA01-UW was determined on polytetrafluoroethylene, Dacron, nitinol, cobalt chromium, and Viabahn endoprosthesis. Individually and in combination, concentrations at 104, 105, 106, 107, and 108 were tested on 2-mm sections of each graft. After each time interval, the prosthetics were rinsed to remove nonattached bacteria, sonicated to release the attached bacteria, spiral plated, and then analyzed for the attached concentration. Results: After 2 hours, there was a significant difference in the median attachment rates on Dacron (14%) compared with nitinol (2.1%), cobalt (1.4%), and Viabahn (0.73%) across all bacterial combinations (P < .05). Pseudomonas aeruginosa achieved the greatest attachment at most concentrations, regardless of the material. At the 24-hour mark, the median attachment for each concentration was greater than the highest initial concentration (108), with nitinol and cobalt having a statistically significant lower attachment (P < .05). Conclusions: Initial attachment is consistently poor, regardless of inoculation concentration, but greater on the synthetic grafts compared with metal stents. However, after 24 hours in a nutrient-poor environment, Staphylococcus aureus and Pseudomonas aeruginosa are still able to achieve full attachment throughout.