title: Infection rate of emergency bolt-kit vs. non-emergency conventional implanted silver bearing external ventricular drainage catheters.
abstract: BACKGROUND
  Bolt-kit systems are increasingly used as an alternative to conventional external cerebrospinal fluid (CSF) drainage systems. Since 2009 we regularly utilize bolt-kit external ventricular drainage (EVD) systems with silver-bearing catheters inserted manually with a hand drill and skull screws for emergency ventriculostomy. For non-emergency situations, we use conventional ventriculostomy with subcutaneous tunneled silver-bearing catheters, performed in the operating room with a pneumatic drill. This retrospective analysis compared the two techniques in terms of infection rates.
  
  
  METHODS
  152 patients (aged 17-85 years, mean=55.4 years) were included in the final analysis; 95 received bolt-kit silver-bearing catheters and 57 received conventionally implanted silver-bearing catheters. The primary endpoint combined infection parameters: occurrence of positive CSF culture, colonization of catheter tips, or elevated CSF white blood cell counts (>4/μl). Secondary outcome parameters were presence of microorganisms in CSF or on catheter tips. Incidence of increased CSF cell counts and number of patients with catheter malposition were also compared.
  
  
  RESULTS
  The primary outcome, defined as analysis of combined infection parameters (occurrence of either positive CSF culture, colonization of the catheter tips or raised CSF white blood cell counts >4/μl)was not significantly different between the groups (58.9% bolt-kit group vs. 63.2% conventionally implanted group, p=0.61, chi-square-test). The bolt-kit group was non-inferior and not superior to the conventional group (relative risk reduction of 6.7%; 90% confidence interval: -19.9% to 25.6%). Secondary outcomes showed no statistically significant difference in the incidence of microorganisms in CSF (2.1% bolt-kit vs. 5.3% conventionally implanted; p=0.30; chi-square-test).
  
  
  CONCLUSIONS
  This analysis indicates that silver-bearing EVD catheters implanted with a bolt-kit system outside the operating room do not significantly elevate the risk of CSF infection as compared to conventional implant methods.
authors.affiliation: Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern 3010 Switzerland.
authors.forename: Jens
authors.initials: J
authors.lastname: Fichtner
authors.affiliation: Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern 3010 Switzerland.
authors.forename: Astrid
authors.initials: A
authors.lastname: Jilch
authors.affiliation: Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern 3010 Switzerland.
authors.forename: Lennart Henning
authors.initials: LH
authors.lastname: Stieglitz
authors.affiliation: Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern 3010 Switzerland.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Beck
authors.affiliation: Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern 3010 Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Raabe
authors.affiliation: Department of Neurosurgery, Inselspital, Bern University Hospital, University of Bern, Bern 3010 Switzerland. Electronic address: Werner.ZGraggen@insel.ch.
authors.forename: Werner J
authors.initials: WJ
authors.lastname: Z' Graggen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002408:Catheters, Indwelling / Q000009:adverse effects* / Q000382:microbiology; D004322:Drainage / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006801:Humans; D007239:Infections / Q000134:cerebrospinal fluid / Q000209:etiology* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D014696:Ventriculostomy / Q000009:adverse effects*; D055815:Young Adult
keywords: Bolt-kit catheters; CSF infection; Cerebrospinal fluid infection; External ventricular drain; Silver-bearing catheters; Ventriculostomy