Infection rates of external ventricular drains are reduced by the use of silver-impregnated catheters

External ventricular drainage (EVD) placement for temporary cerebrospinal fluid (CSF) diversion is a frequent therapeutic procedure. Several types of EVD catheters are currently available, some of which have an antibacterial effect. This study compares the rates of CSF infections in patients with different types of EVD catheters.

This is a retrospective study of 403 patients with a total of 529 implanted EVDs. We analyze the occurrence of EVD-associated infections, microbiological diagnosis, type of EVD catheter (plain polyurethane vs. silver-impregnated), duration of CSF diversion, primary disease, and outcome.

There were a total of 29 patients with EVD infections in the whole study group (7.1 %). A pathogen was detected in all cases. Coagulase-negative staphylococci were detected most frequently (20 out of 29 cases, 70 %). The rate of infections by catheter type was 7.6 % (11 of 145) and 13.8 % (4 out of 29) for two different types of non-coated polyurethane catheters. Silver-impregnated polyurethane catheters became infected in 6.1 % (14 out of 228). The differences between non-coated and silver-coated catheters were statistically significant.

This study provides comparative data on EVD infections with regard to the type of catheter. Silver-impregnated catheters showed significantly lower infection rates when compared to non-impregnated catheters. The results are critically discussed and compared with the published literature.