The effectiveness of sterilization for flexible ureteroscopes: A real-world study

Am J Infect Control. 2017 Aug 1;45(8):888-895. doi: 10.1016/j.ajic.2017.03.016. Epub 2017 Jun 15.


Background: There are no guidelines or quality benchmarks specific to ureteroscope reprocessing, and patient injuries and infections have been linked to ureteroscopes. This prospective study evaluated ureteroscope reprocessing effectiveness.

Methods: Reprocessing practices at 2 institutions were assessed. Microbial cultures, biochemical tests, and visual inspections were conducted on sterilized ureteroscopes.

Results: Researchers examined 16 ureteroscopes after manual cleaning and sterilization using hydrogen peroxide gas. Every ureteroscope had visible irregularities, such as discoloration, residual fluid, foamy white residue, scratches, or debris in channels. Tests detected contamination on 100% of ureteroscopes (microbial growth 13%, adenosine triphosphate 44%, hemoglobin 63%, and protein 100%). Contamination levels exceeded benchmarks for clean gastrointestinal endoscopes for hemoglobin (6%), adenosine triphosphate (6%), and protein (100%). A new, unused ureteroscope had hemoglobin and high protein levels after initial reprocessing, although no contamination was found before reprocessing.

Conclusions: Flexible ureteroscope reprocessing methods were insufficient and may have introduced contamination. The clinical implications of residual contamination and viable microbes found on sterilized ureteroscopes are unknown. Additional research is needed to evaluate the prevalence of suboptimal ureteroscope reprocessing, identify sources of contamination, and determine clinical implications of urinary tract exposure to reprocessing chemicals, organic residue, and bioburden. These findings reinforce the need for frequent audits of reprocessing practices and the routine use of cleaning verification tests and visual inspection as recommended in reprocessing guidelines.

Keywords: Borescope; Contamination; Cultures; Microbial; Reprocessing.

MeSH terms

  • Disinfection / methods*
  • Equipment Contamination / prevention & control*
  • Equipment Reuse
  • Guideline Adherence
  • Humans
  • Infection Control / methods
  • Ureteroscopes / microbiology*