Silver iontophoretic catheter: a prototype of a long-term antiinfective vascular access device.

A silver iontophoretic catheter (SIC) was developed consisting of two electrically charged parallel silver wires helically wrapped around the proximal segment of a vascular catheter. In vitro and in vivo activities of this catheter were compared with those of an aseptic catheter coated with chlorhexidine and silver sulfadiazine (CH/SS). The SIC demonstrated broad-spectrum in vitro inhibitory activity against bacteria and Candida albicans comparable to that of the CH/SS-coated catheter. The durability of activity was determined by incubating catheters in serum at 37 degrees C for various time intervals. After 30 days, the antimicrobial activity of the SIC did not change significantly, while that of the CH/SS-coated catheter was reduced to a suboptimal level. In a rabbit model, the SIC was safe and significantly more efficacious than the CH/SS-coated catheter in preventing colonization with Staphylococcus aureus (P < .05). The SIC has broad-spectrum inhibitory activity of long durability and is highly efficacious in preventing colonization in vivo.