Industry News – FDA Safety Communication: Supplemental Measures to Enhance Duodenoscope Reprocessing

News from the world of endoscopy has not been good recently, with patients dying and being sickened after catching antibiotic resistant infections from inadequately cleaned endoscopes, especially duodenoscopes; even though the affected hospitals followed the manufacturer’s cleaning and reprocessing instructions.  The problem arises because the complexity of the scope makes it very difficult to clean it properly and remove all potentially infectious material. An FDA advisory committee made several recommendations on improving duodenoscope reprocessing, including sterilizing rather than just disinfecting endoscopes. The FDA has now issued supplemental guidance on how to reduce the risk of disease transmission for ERCP endoscopes (side-viewing duodenoscopes).

The FDA says that at a minimum it is essential that the manufacturers’ cleaning and reprocessing instructions be followed meticulously. Even doing this, some ‘scopes still remain contaminated and so the FDA recommends that those institutions that have the relevant capabilities introduce one or more of the following supplemental measures to reduce the chance of decontamination.

  • Microbiological Culturing
  • Ethylene Oxide Sterilization
  • Use of a Liquid Chemical Sterilant Processing System
  • Repeat High-Level Disinfection

Microbiological culturing: Microbiological culturing involves sampling the distal end and channels of the scope and culturing those samples to identify any bacterial contamination that may be present on the scope after reprocessing to assess the reprocessing efficacy and identify contaminated scopes.

EtO Sterilization: When possible and practical, duodenoscopes should be sterilized due to the greater margin of safety provided by sterilization. Sterilization is a validated process used to render a product free from all viable microorganisms, but EtO sterilization is not available at every facility.

Use of a liquid chemical sterilant processing system following cleaning and high-level disinfection: A liquid chemical sterilant (LCS) processing system is used after high level disinfection. However, because this process requires rinsing with highly purified (but not sterile) water following device sterilization, the device does not remain completely free of all viable microbes.

Repeat High Level Disinfection: High level disinfection (HLD)  involves immersing the device with a disinfectant and is expected to inactivate all microorganisms except for large numbers of bacterial endospores, usually using an automatic endoscope reprocessors (AERs), a machine that wash and high-level disinfect endoscopes and scope accessories to decontaminate them between uses.

Since most high level disinfectants are sterilants, given enough time, these last two are really variations of the same idea. If after high level disinfection x% of the duodenoscopes still contain viable contamination, then disinfecting more than once or sterilizing for a longer time should reduce the chance of infection.

Comment: Of these methods, the EtO sterilization is probably the most effective, since after sterilization all the microorganisms should be destroyed, with the liquid chemical sterilization closely following since its final product is not sterile. For those facilities that cannot perform sterilization, repeating the high level disinfection and culturing will help reduce the risk of transmission of disease to patients. However, the most important factor for all of these measures to work, is to ensure the scope is properly cleaned.