Disposable elevator cap duodenoscopes exhibited reduced contamination after high-level disinfection compared with standard scope designs, without affecting the technical performance and safety of endoscopic retrograde cholangiopancreatogaphy, according to results from the multicenter randomized ICECAP Trial.
In the wake of a series of outbreaks of multidrug-resistant infections associated with ERCP in the United States and Europe between 2012 and 2013, the FDA ordered the three manufacturers of reusable duodenoscopes currently marketing in the United States—Fujifilm, Olympus and Pentax—to conduct postmarketing surveillance studies to determine rates of contamination after clinical use and reprocessing of their fixed endcap duodenoscopes. The final results of those studies found that as much as 6.6% of samples tested positive for high-concern organisms even after reprocessing.
The agency “recommended that the industry should migrate to scope solutions that either have disposable components, where the elevator cap of the duodenoscope is disposable, or where the endoscope itself is a single-use, disposable scope,” said Klaus Mergener, MD, PhD, MBA, MASGE, an affiliate professor at the University of Washington School of Medicine, in Seattle, and the past president of the American Society for Gastrointestinal Endoscopy (ASGE).
Over the past several years, the manufacturers have phased out their legacy reusable duodenoscopes with fixed endcaps and replaced them with disposable endcap scopes. “I don’t know about every single hospital in the U.S., but it’s fair to say that if your hospital has not replaced their entire duodenoscope fleet already, they will be doing so soon. The primary question that remains, which the ICECAP study and others are addressing, is whether or not it is advisable to go one step further and pursue general adoption of the fully disposable scopes now offered by Boston Scientific and Ambu,” Dr. Mergener said.
‘A Potential Solution’
The ICECAP, or Infection Control in ERCP using a Duodenoscope with a Disposable Cap, trial, which was conducted at two tertiary ERCP centers in Canada, enrolled 518 patients between December 2019 and February 2022, 259 undergoing ERCP with disposable elevator cap duodenoscopes and 259 with standard duodenoscopes, (JAMA Intern Med 2023;183[3]:191-200). The scopes used in both study arms, all from Pentax Medical, were required to have been in clinical use for more than 12 months but not more than 24 months, and they underwent two cycles of high-level disinfection followed by steam sterilization before sample collection.
Persistent microbial contamination was detected in 24 of 214 (11.2%) standard duodenoscopes and 8 of 208 (3.8%) disposable elevator cap duodenoscopes (P=0.004), corresponding to a relative risk of 0.34 (95% CI, 0.16-0.75), and the number needed to treat to avoid persistent contamination was 13.6 (95% CI, 8.1-42.7). Technical success using the disposable cap scope was noninferior to that of the standard scope (94.6% vs. 90.7%; P=0.13). There were no differences between groups in adverse events and other secondary outcomes.
“The findings of our study support the FDA recommendation to transition to duodenoscopes with novel designs,” wrote the authors, led by Nauzer Forbes, MD, MSc, FRCPC, an assistant professor of medicine and the director of the therapeutic endoscopy training program in the Division of Gastroenterology and Hepatology at the University of Calgary, in Alberta. “Although entirely disposable duodenoscopes offer the ability to completely eliminate persistent microbial contamination, the high costs, lower technical performance and environmental effects all limit the widespread use of these devices. Duodenoscopes with a disposable elevator cap offer a potential solution for substantially reducing persistent microbial contamination that is scalable, with an incremental cost of approximately $50, or 3% to 7% of overall procedural costs.”
Dr. Mergener noted that these results are consistent with those of a trial conducted by Fujifilm of its own disposable endcap scopes (FDA. 522 Postmarket Surveillance Studies Database). “With the Fuji scope, the contamination rate was 1.1%, down from a baseline contamination rate of over 5%,” he said. “In addition to that study and this investigator-initiated trial, Pentax and Olympus are also completing FDA-mandated studies of their disposable endcap scopes, and I expect that those will produce similar results.”
High Performance, Low Infection Risk
These findings lead to the question of how low the contamination rate needs to be for a reusable scope to be acceptable. “If we reuse instruments in medicine, there will never be a 0% rate of contamination,” Dr. Mergener said. “But you are weighing the non-zero contamination risk against the advantage of using a much more high-quality and detailed reusable scope rather than a one-time disposable product. With a single-use scope, the infection rate may be zero, but the tradeoff is that you are using a scope that is, by necessity, made of cheaper products and may not perform quite as well as the more expensive reusable scopes.”
Dr. Mergener said that based on his conversations with colleagues, he believes that most of them feel the residual risk for transmitting an infection with a disposable endcap scope is within a quite low and acceptable range. “I believe the majority of the physician community is of the opinion that these modifications are sufficient to address the issue of infection transmission in duodenoscopy,” he said.
That’s the conclusion of Harish Gagneja, MD, FACG, FASGE, a gastroenterologist with Austin Gastroenterology, in Texas. “I would like to see zero contamination, but that is not possible with a reusable scope. When you combine the extremely low risk of contamination with the disposable endcap with the fact that we know that not all contamination causes infection, the actual risk of infection to patients becomes extremely small—something like 0.0005%,” he said. “At the same time, after having used the disposable endcap scopes for more than a year and a half, I have not seen any difference in the performance of these scopes compared with legacy scopes. On the other hand, when I use a disposable scope, I feel like I’m holding a toy. There’s clearly a decrease in performance. The disposable endoscopes also have a significant environmental impact and added cost. Taking all that into account, for the vast majority of ERCP cases, reusable scopes with disposable endcaps make sense.”
Single-use disposable duodenoscopes may still have niche applications with certain high-risk patients, however. “For example, if I had a patient who was profoundly immunosuppressed due to high-dose chemotherapy or an immunologic disorder, I would choose a single-use scope,” Dr. Mergener said. “Or if a patient already had a known infection with an antibiotic-resistant organism and then required ERCP, I would not want to employ a reusable scope and take the risk of transmitting that organism to the next patient. Those high-risk patients are a small group, probably significantly less than 5% of all the ERCPs that I do, but in that group, single-use scopes might have an application.”
Dr. Gagneja agreed with these scenarios, and added one more: “In very low-volume centers, where they may do a handful of ERCPs a year and may not have good reprocessing capabilities, disposable scopes may make sense.”
When asked about potential drawbacks to partially disposable endoscopes, Dr. Mergener told Gastroenterology & Endoscopy News, “all in all, I agree that in coming up with better solutions to reduce the number of contaminated ERCP scopes, the new endcap scopes are providing such a solution, but they come with a new set of potential downsides, specifically the need to be diligent in assembling the removable cap with the tip of the endoscope. Provided this is done correctly, mishaps such as unintentional detachment of the tip can be minimized if not completely avoided, and the overall benefit of these scopes probably outweigh their downsides. But it behooves us to continue to look for even better solutions.”
To that end, he expects all scope makers will continue to work on other solutions to further reduce infection risk, shifting focus to the reprocessing side. “There are many steps in the cleaning of endoscopes that are quite error-prone because they are done by humans, such as precleaning and insument channel brushing. “A number of companies are trying to automatize the currently manual steps of endoscope cleaning, and this is where attention needs to be focused in the coming years. On the scope side, I don’t think there is much more that needs to be done.”
—Gina Shaw
Dr. Gagneja reported no relevant financial disclosures. Dr. Mergener reported financial relationships with Boston Scientific, Kate Farms, Pentax Medical and Sebela Pharmaceutical. Drs. Gagneja and Mergener are members of the Gastroenterology & Endoscopy News editorial board.
This article is from the April 2023 print issue.