title: Duration of in vivo antimicrobial activity of antibiotic-impregnated cerebrospinal fluid catheters.
abstract: OBJECTIVE
  Shunt infection is a major neurosurgical concern even after 50 years of experience with shunt surgery. Staphylococcus species are responsible for the majority of cerebrospinal fluid shunt infections. In vitro, antibiotic-impregnated cerebrospinal fluid shunt catheters (AIC) have demonstrated protection against multiple staphylococcus species and strains for reasonable periods. We aim to study the longevity of antimicrobial activity of AIC in vivo by using explanted catheters.
  
  
  METHODS
  Twenty-five AICs (rifampicin [0.054%] and clindamycin [0.15%]) were explanted from 18 patients for noninfectious reasons, from 11 to 700 days postimplantation. The catheters were set up on standardized Staphylococcus aureus culture plates to detect antimicrobial activity. Unused fresh AIC segments were used as control in each culture plates.
  
  
  RESULTS
  Fourteen explanted AICs demonstrated persistent antimicrobial activity against staphylococcal species. Antimicrobial activity was detected for a period of implantation up to 127 days. This is longer than that predicted by in vitro models.
  
  
  CONCLUSIONS
  The persistent antimicrobial activity is likely to translate to ongoing in vivo antimicrobial protection. This period of protection exceeds that during which most shunt infections occur.
authors.affiliation: Department of Neurosurgery, Monash Medical Centre, Clayton, Australia.
authors.forename: Ananthababu
authors.initials: A
authors.lastname: Pattavilakom
authors.forename: Despina
authors.initials: D
authors.lastname: Kotasnas
authors.forename: Tony M
authors.initials: TM
authors.lastname: Korman
authors.forename: Chris
authors.initials: C
authors.lastname: Xenos
authors.forename: Andrew
authors.initials: A
authors.lastname: Danks
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002408:Catheters, Indwelling; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects* / Q000379:methods; D002648:Child; D002675:Child, Preschool; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage*; D006801:Humans; D007223:Infant; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000517:prevention & control; D013211:Staphylococcus aureus; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible