18. The Indwelling Bladder Catheter: Attempts to Prevent Infection and the Development of Bacterial Biofilms

The Foley indwelling bladder catheter is the most commonly deployed prosthetic medical device. While this catheter provides a convenient way to drain urine from the bladder, it also provides easy access to the bladder for bacteria contaminating the skin insertion site. In addition the catheter undermines the basic antibacterial defenses within the lower urinary tract. As a result, catheter-associated urinary tract infections are the most common infections acquired by patients in healthcare facilities. Bacterial biofilms form readily on these catheters and play important roles in the pathogenesis of the conditions that complicate the care and seriously threaten the health of catheterized patients. This chapter reviews the many attempts that have been made to prevent infection and biofilm formation by incorporating antimicrobial agents such as silver, nitrofurazone, minocycline, rifampicin, other antibiotics and biocides into catheters. The failure of antimicrobial catheters to prevent the development of the particularly troublesome crystalline biofilms is discussed and the need explained for fundamental changes in the design of catheters.