IN-VITRO ANTIMICROBIAL EFFICACY OF SILVER IONTOPHORETIC CATHETER

A silver iontophoretic catheter was designed consisting of two silver wires connected to an electric power source and disposed in a parallel and helical manner around the proximal subcutaneous segment of a sili cone catheter. In an in vitro tunnelled bridge model the silver iontop horetic catheter prevented the migration of Staphylococcus epidermidis from the highly contaminated hub to the sterile tip over a 40-d perio d. The silver impregnated cuff and electrically charged wires made of aluminium or iron delayed migration for only 72 h. A modified Kirby-Ba uer technique, used to test the inhibitory activity of antimicrobial c atheters, showed that the silver iontophoretic catheter has a broad sp ectrum inhibitory activity against Gram-positive bacteria, Gram-negati ve bacteria and Candida albicans. The silver iontophoretic catheter pr ovides a long-term electrochemical barrier against the migration of or ganisms from the external contaminated environment into the sterile in travascular compartment. (C) 1996 Elsevier Science Limited