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

https://doi.org/10.1016/j.ajic.2017.03.016Get rights and content

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.

Section snippets

Setting and design

This prospective study was conducted at 2 large multispecialty health care facilities in the mid-western United States. A waiver was granted by the institutional review boards at both sites because no human subjects were involved. Data regarding ureteroscope models, acquisition dates, procedural use, and repair histories were collected by site personnel. Site visits were conducted to examine patient-ready ureteroscopes and observe reprocessing practices in June (site A) and August (site B) 2016.

Ureteroscope characteristics

Researchers received administrative data for 13 ureteroscopes at site A (A-1 through A-13) and 4 ureteroscopes at site B (B-1 through B-4) (Table 1). The mean ureteroscope age was 2.1 years (range, 0.21-5.6 years) at site A and 2.2 years (range, 1.0-2.8 years) at site B. Ureteroscopes at both sites were used infrequently (average <1/week). Sites documented a total of 49 repairs before the study. Ureteroscopes required repair after an average of 14 uses at site A and 42 uses at site B. Common

Discussion

This study detected substantial contamination on sterilized ureteroscopes, including hemoglobin, ATP, and protein. Microbial cultures were positive for samples from 2 of 16 ureteroscopes. All study ureteroscopes had visible irregularities, including scratches, dents, filaments of debris, rusty-yellow discoloration, oily deposits, residual fluid, or foamy white residue. Visible debris protruding into the channel was observed in a ureteroscope (A-9) with microbial growth and the highest levels of

Conclusions

This systematic evaluation of reprocessing effectiveness found that 100% of patient-ready flexible ureteroscopes had visible irregularities and residual contamination that exceeded benchmarks for manually cleaned gastrointestinal endoscopes. Microbial growth occurred in samples from 2 of 16 ureteroscopes, indicating a failure of the sterilization process. Suboptimal reprocessing practices may have contributed to the findings. This study was not designed to address the association between

Acknowledgments

The authors thank site personnel for providing a dedicated operating room for sampling and logistical support during this study. The authors also thank Michelle Alfa, PhD, for providing expertise about interpreting and performing microbial cultures; Lisa Mattson, MBA, for handling study logistics; and Miriam Amelang, BA, for providing editorial assistance. The authors also thank reprocessing staff for facilitating research activities, including providing endoscopes and re-reprocessing them

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  • Cited by (0)

    Supported by a research grant from Boston Scientific. Supplies and materials were provided by HealthMark Industries, which provided a borescope, hemoglobin tests, and protein tests, and 3M Company, which provided the adenosine triphosphate testing devices and swabs. The companies were not involved in designing the study, collecting data, interpreting results, or preparing the manuscript. Ofstead & Associates Inc, provided research support.

    Conflicts of interest: CLO is employed by Ofstead & Associates, Inc, which has received research funding and speaking honoraria related to infection prevention from 3M Company, Medivators, HealthMark Industries, STERIS Corporation, Boston Scientific, Advanced Sterilization Products, and Invendo Medical. OLH, MRQ, EAJ, JEE, and HPW are employed by Ofstead & Associates, Inc.

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