DURATION OF PROTECTIVE ACTIVITY OF CEREBROSPINAL-FLUID SHUNT CATHETERS IMPREGNATED WITH ANTIMICROBIAL AGENTS TO PREVENT BACTERIAL CATHETER-RELATED INFECTION

This study determined the protective effect of antibacterial processin g of cerebrospinal fluid (CSF) shunt catheters against infection with staphylococci, which is an important complication following CSF shunt placement for hydrocephalus. Also examined is the effect of a conditio ning film such as that seen on the luminal surface of shunts used in p osthemorrhagic hydrocephalus. Conventional preventative measures, incl uding antimicrobial prophylaxis, confer a temporary or unproven benefi t. The authors have therefore developed a process for impregnation of CSF shunts with rifampicin and clindamycin, and this has been shown pr eviously to achieve the target duration of 28 days of protective activ ity in vitro. The present study demonstrates the limit of the period o f protection and the efficacy of the processing against a wide range o f staphylococci, particularly in the presence of a plasma protein cond itioning film. Five strains of Staphylococcus aureus and 17 coagulase- negative staphylococci, all clinical isolates, were inoculated into th e shunts at 2-week intervals until failure of antimicrobial protection occurred. The results showed that the process protected against all s trains for between 42 and 56 days and that the conditioning film did n ot diminish the protection. Catheters processed by this method show pr omise of significant reductions in the incidence of CSF shunt infectio ns.