Urinary tract infections accounts for over 40% of all
nosocomial infections, and almost all these
infections are associated with
indwelling catheters. The acquisition of
urinary tract infections following urinary bladder catheterizations are associated with nearly a threefold increase in mortality among hospitalized patients. The economic impact of nosocomial urinary
infections is difficult to assess. An estimate of the cost of these
infections have shown that patients with hospital-acquired
urinary tract infections secondary to
indwelling catheters, spent an average of 2.4 additional days in the hospital. Bearing this in mind, even a marginal decrease in
urinary tract infections may be cost-effective. In two randomized prospective clinical studies we have shown that coating
urinary catheters with
silver significantly reduces the
infection rate during short-term catheterization (less than 7 days). We also showed that
silver coating of
urinary catheters prevented adherence and growth of Pseudomonas aeruginosa on the
catheter material. Another risk from using
indwelling catheters is an inflammatory reaction of the urethral mucosa leading to
stricture formation. Several aetiological factors whereby
indwelling catheters may cause a
urethral stricture have been discussed. During the last years much attention has been paid to the
catheter material as such, especially
latex, and its role in
stricture formation.
Urinary catheters are made from a variety of materials combined with different chemicals. It seems as if these chemical substances can dissolve from the
catheter material, causing inflammatory reactions. Using a cell culture technique with a mouse fibroblast cell line (BALBc/3T3), and an animal model with implantation of
catheter material into the urethra, we assessed both in vitro cytotoxicity (IC50) and inflammatory reactions in vivo from different
catheter materials. The studies confirmed that especially
latex materials do not have both cytotoxic effects and cause considerable
inflammation within the urethral mucosa. By coating the
catheters with
silver, the cytotoxicity could be significantly reduced as compared with pure
latex and
hydrogel coated
latex catheters. Several studies have demonstrated a cytotoxic effect from
catheter materials, indicating that this may be of importance in urethral
inflammation. However, the exact mechanisms behind this phenomenon is not known. In an attempt to explain the inflammatory reaction within the urethra secondary to an
indwelling catheter, we investigated the influence of the nervous system on experimentally induced urethral
inflammation. Our findings indicate that an important part in
catheter induced
inflammation is played by neurogenic reactions.