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

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Acta Neurochir (2013) 155:875–881

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.

Methods 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.

Results 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 noncoated 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.

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

Comparison of Infection Rate With the Use of Antibiotic-Impregnated vs Standard Extraventricular Drainage Devices: A Prospective, Randomized Controlled Trial

Neurosurgery 71:6–13, 2012 DOI: 10.1227/NEU.0b013e3182544e31

External ventricular drainage (EVD) catheters provide reliable and accurate means of monitoring intracranial pressure and alleviating elevated pressures via drainage of cerebrospinal fluid (CSF). CSF infections occur in approximately 9% of patients. Antibiotic-impregnated (AI) EVD catheters were developed with the goal of reducing the occurrence of EVD catheter-related CSF infections and their associated complications.

OBJECTIVE: To present an international, prospective, randomized, open-label trial to evaluate infection incidence of AI vs standard EVD catheters.

METHODS: Infection was defined as (1) proven infection, positive CSF culture and positive Gram stain or (2) suspected infection: (A) positive CSF culture with no organisms identified on initial Gram stain; (B) negative CSF culture with a gram-positive or -negative stain; (C) CSF leukocytosis with a white blood cell/red blood cell count .0.02.

RESULTS: Four hundred thirty-four patients underwent implantation of an EVD catheter. One hundred seventy-six patients in the AI-EVD cohort and 181 in the standard EVD catheter cohort were eligible for evaluation of infection. The 2 groups were similar in all clinical characteristics. Proven infection was documented in 9 (2.5%) patients (AI: 4 [2.3%] vs standard: 5 [2.8%], P = 1.0). Suspected infection was documented in 31 (17.6%) patients receiving AI and 37 (20.4%) patients receiving standard EVD catheters, P = .504. Duration of time to suspected infection was prolonged in the AI cohort (8.8 6 6.1 days) compared with the standard EVD cohort (4.6 6 4.2 days), P = .002.

CONCLUSION: AI-EVD catheters were associated with an extremely low rate of catheter-related infections. AI catheters were not associated with risk reduction in EVD infection compared to standard catheters. Use of AI-EVD catheters is a safe option for a wide variety of patients requiring CSF drainage and monitoring, but the efficacy of AI-EVD catheters was not supported in this trial.