The FDA issued a detailed MedWatch report yesterday informing health care facilities that some additional measures may be necessary to further reduce the risk of contaminated duodenoscopes transmitting CRE, or carbapenem-resistant Enterobacteriacae.

Entitled, “Duodenoscope Reprocessing: FDA Safety Communication – Supplemental Measures to Enhance Reprocessing,” the FDA’s alert discusses four specific supplemental measures that some health care facilities have found may be effective for stopping outbreaks of CRE or a related ‘superbug’ following endoscopic retrograde cholangiopancreatography, or ERCP.

Combined with strict adherence to the duodenoscope manufacturer’s reprocessing instructions, these four measures advanced in the FDA’s alert are:

  1. microbiological culturing
  2. ethylene oxide sterilization
  3. the use of a liquid chemical sterilant processing device
  4. and “repeat” high-level disinfection

Several newspaper articles

After its release yesterday, many popular newspapers across the U.S. published articles discussing this alert’s recommendations and potential shortcomings.

Three of these articles are, in particular:

My perspectives

Like these three newspaper articles, the yesterday’s FDA alert continues to place important focus on the risk of duodenoscopes infecting patients with a deadly superbug.

This past Monday, a day before the FDA’s alert was issued, I published the article:

This article reiterates my concerns that other types of flexible endoscopes — including bronchoscopes — also pose a risk of transmitting deadly CRE, although yesterday’s FDA alert could be interpreted to suggest that only duodenoscopes pose this risk.

I first expressed concerns about other instrument types similarly posing a superbug risk more than two weeks ago, in July, in my article, “A ‘Superbug’ Outbreak in 2014 Linked to Bronchoscopes: An Under-recognized Risk?” (July 21, 2015).

Bronchoscopes are used during pulmonary applications to diagnose and treat diseases of the lungs.

Bronchoscopes can become contaminated with CRE, too

The Los Angeles Times published its own front-page article this past weekend that, in part, follows up on the my previously expressed concerns that superbug outbreaks are not limited to duodenoscopes:

Indeed, yesterday’s FDA alert overlooked a potentially salient and growing health risk: the potential for contaminated bronchoscopes and other types of reusable medical instrumentation — not just duodenoscopes — to transmit deadly CRE infections.

The Los Angeles Times pursues further this bronchoscope risk

Hours after its first article was published yesterday, The Los Angeles Times published a second article entitled, “Superbug outbreaks: FDA issues more scope-cleaning guidance to hospitals” (August 4, 2015), which pursues further this potentially significant oversight by the FDA.

In this report, the Times, in effect, asked the FDA why a discussion about the risk of bronchoscopes and other reusable instrumentation transmitting CRE was not included in its Medwatch alert issued earlier in the day.

The following excerpts appear in that Times article:

“The FDA, which regulates medical devices, has been sharply criticized by lawmakers and patient advocates for not warning hospitals sooner about the well-documented threat of scope-related infections.

“Muscarella, the endoscopy consultant, said he didn’t understand why health officials failed to address the risk posed by other types of medical scopes (such as bronchoscopes) in Tuesday’s report.

“At the FDA meeting in May, several experts on the panel and researchers pointed out that other devices, such as bronchoscopes and gastroscopes, can have traces of potentially infectious material even after cleaning.”

As I previously reported, each of the following types of endoscopes and associated reusable instrumentation has been recently linked to the transmission of multidrug-resistant bacteria, including CRE:

  • duodenoscopes (used during ERCP)
  • linear echo-endoscopes (used during endoscopic ultrasound or “EUS”)
  • bronchoscopes
  • cystoscopes and associated urological instrumentation

Cystoscopes and related instrumentation are used to examine, diagnose and treat diseases of the bladder.

The appropriate time

According to the Times’ second article yesterday, the FDA provided the following statement, in response to questions about the risk of bronchoscopes transmitting CRE:

“A spokeswoman said the FDA ‘continues to investigate infections associated with other reprocessed reusable devices and will provide updates as appropriate.'”

It could be reasonably argued that the appropriate time for health officials to have proactively informed the public about the risk of these other types of flexible endoscopes transmitting CRE would have been in yesterday’s FDA Medwatch alert.

Redesigning endoscopes?

Yesterday’s Los Angeles Times article (“Superbug outbreaks: FDA issues more scope-cleaning guidance to hospitals” [August 4, 2015]) also reports that:

“Work is also underway on redesigning these duodenoscopes so they are easier to clean and safer to reuse. Jennifer Dooren, an agency spokeswoman, said the FDA is ‘working with manufacturers as they explore design innovations’ such as disposable parts for the hardest-to-clean areas or devices that could be disassembled.”

This is one of the few instances I am aware of in which the FDA publicly indicates that the agency is working with manufacturers to redesign duodenoscopes as a mitigation for preventing superbug infections. Notably, the FDA’s position is consistent with my previously published comments.

Previously, the FDA has said that it cannot require manufacturers to redesign their devices.

Quality and Safety Services for Hospitals, Manufacturers, Patients:  Click here to read about Dr. Muscarella’s quality services committed to reducing the risk of healthcare-associated infections, including CRE outbreaks linked to contaminated endoscopes and other reusable medical equipment.

A redesign vs. sterilization: My perspectives

I favor considering the redesign of some endoscope types in lieu of the more expensive proposal, endorsed by some medical experts, that hospitals instead purchase potentially expensive sterilization equipment to improve safety and overcome what the FDA has expressed are potentially significant limitations with the duodenoscope’s current design.

But, by redesign, I do not limit my focus to improving the “cleanability” of the duodenoscope’s (or linear echo-endoscope’s) forceps elevator mechanism, or to redesigning duodenoscopes with a removable distal tip to facilitate the endoscope’s more effective cleaning, brushing and disinfection, which I also advocate.

Instead, I additionally favor evaluating the feasibility of redesigning flexible endoscopes whose specifications require the use more durable materials in the construction of their internal channels.

The use of materials demonstrated to be of a sufficiently good quality, both in the original design of new endoscopes and in the repair of used ones, takes on particularly significance for (un-regulated) third party servicing companies, which hospitals often use to repair their damaged endoscopes.

The removal of a detachable distal tip for better access and cleaning of the endoscope is an interesting and likely effective suggestion to prevent CRE outbreaks. It is already employed in Europe. But a detachable tip is not, per se, applicable to cystoscopes or bronchoscopes, which also have been linked to CRE outbreaks.

At least for bronchoscopes and gastrointestinal endoscopes, some published data suggest that their internal channels may become worn and torn, even during their proper clinical use, causing holes and crevices to develop, which may retain and transmit infectious bacteria, including CRE, to patients, despite the endoscope being thoroughly cleaned in accordance with manufacturers’ instructions.

Improvements in the quality and construction of endoscopes’ internal channels using more durable materials that make them less prone to wear, tear and damage might reasonably contribute to a significant reduction in the risk of CRE outbreaks.

Improvements in the effectiveness and reliability of the “leak testing” process used to test the integrity of endoscopes during their cleaning may also further reduce this risk.

Article by: Lawrence F Muscarella, PhD; posted: August 5, 2015, Rev C.

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