title: Image-guided percutaneous disc sampling: impact of antecedent antibiotics on yield.
abstract: OBJECTIVE
  To evaluate the effect of antecedent antimicrobial therapy on diagnostic yield from percutaneous image-guided disc-space sampling.
  
  
  METHODS
  A retrospective review of the electronic health records of all patients who underwent image-guided percutaneous sampling procedures for suspected discitis/osteomyelitis over a 5-year period was performed. One hundred and twenty-four patients were identified. Demographics, medical history, and culture results were recorded as well as duration of presenting symptoms and whether antecedent antibiotic therapy had been administered.
  
  
  RESULTS
  Of the 124 patients identified who underwent image-guided percutaneous disc-space sampling, 73 had received antecedent antibiotic treatment compared with 51 who had not. The overall positive culture rate for the present study population was 24% (n=30). The positive culture rate from patients previously on antibiotics was 21% (n=15) compared with 29% (n=15) for patients who had not received prior antibiotic treatment, which is not statistically significant (p=0.26). Eighty-six percent (n=63) of patients who had antecedent antibiotics received treatment for 4 or more days prior to their procedure, whereas 14% (n=10) received treatment for 1-3 days prior to their procedure. The difference in culture positivity rate between these two groups was not statistically significant (p=0.43). Culture results necessitated a change in antibiotic therapy in a third of the patients who had received antecedent antibiotic therapy.
  
  
  CONCLUSIONS
  Antecedent antibiotic therapy, regardless of duration, did not result in significantly diminished diagnostic yield from percutaneous sampling for suspected discitis/osteomyelitis. The present results suggest that percutaneous biopsy may nonetheless yield positive diagnostic information despite prior antimicrobial therapy. If the diagnostic information may impact choice of therapeutic regimen, percutaneous biopsy should still be considered in cases where there is a history of prior antimicrobial therapy.
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St, 2nd Floor, Suite 200 East Wing, Pittsburgh, PA 15213, USA. Electronic address: agarwalv@upmc.edu.
authors.forename: V
authors.initials: V
authors.lastname: Agarwal
authors.affiliation: Department of Radiology, University of Washington Medical Center, 1959 NE Pacific St, Box 357115, Seattle, WA 98195, USA.
authors.forename: S
authors.initials: S
authors.lastname: Wo
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St, 2nd Floor, Suite 200 East Wing, Pittsburgh, PA 15213, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Lagemann
authors.affiliation: Section of Neuroradiology, Imaging Institute, Cleveland Clinic Main Campus, 9500 Euclid Avenue, Desk L10, Cleveland, OH 44195, USA.
authors.forename: J
authors.initials: J
authors.lastname: Tsay
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St, 2nd Floor, Suite 200 East Wing, Pittsburgh, PA 15213, USA.
authors.forename: W T
authors.initials: WT
authors.lastname: Delfyett
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015299:Discitis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology*; D005260:Female; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology*; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents