Dr. Tyberg is an Associate Professor of Medicine, Vice Chair of Clinical Affairs, Director of Therapeutic EUS and Associate Director of Endoscopy at Rutgers Robert Wood JohnsonMedical School.
Introduction
Duodenoscope-associated bacterial infections have been increasingly recognized as a significant
patient-safety concern. While in the past these infections have been attributed to non-compliance
with cleaning protocols, it has become clear that bacteria can persist on duodenoscopes despite
adequate reprocessing.3 This increase in infection risk related to duodenoscopes has been linked
to components of the duodenoscope which are difficult to access during the cleaning process.1
The United States Food and Drug Administration (FDA) is requiring hospitals and endoscopy
facilities to transition to duodenoscope designs that include disposable components. Industry has
responded with the introduction of six new FDA-approved duodenoscopes.7 These new devices
provide a solution for duodenoscope-related infections but are associated with both challenges
and opportunities in widespread adoption.
Defining the Problem
Studies determined there have been at least 24 MDRO outbreaks associated with ERCPs
worldwide since 2008 leading to 490 patient infections and at least 32 deaths.1 On February 19 th ,
2015, the FDA published the first duodenoscope-related safety communication stating that the
design of duodenoscopes may impede effective cleaning and lead to the potential transmission of
microorganisms in duodenoscopes undergoing high-level disinfection (HLD). The FDA ordered
a postmarket surveillance study (“522 study”) to better understand how these devices are
reprocessed in real-world settings and the resulting contamination rates. The published results
found that 5.4% of samples that were collected tested positive for organisms of high concern
(e.g., E. coli and P. aeruginosa) and 3.6% of the collected samples tested positive for organisms
that were of low to moderate concern (>100 colony-forming units (CFUs)) which constituted an
overall contamination rate of 9%.2 A meta-analysis by Larsen et al found that the presence of
bacteria after reprocessing of duodenoscopes was 15.25%.3 Duodenoscopes have historically been reprocessed using HLD. Newer methods of cleaning such as double HLD (dHLD), liquid chemical sterilization, and ethylene oxide gas sterilization (EtO) offer some improvement. Larsen et al showed a pooled contamination rate of 9.20% after dHLD or EtO sterilization compared to 16.14% using HLD alone. (3) Naryzhyny et al found up to 1.2% of duodenoscopes remained contaminated with high-risk organisms after EtO.4 In 2019, the FDA determined that the best solution to reduce the risk of infection-transmission via duodenoscopes was through innovative device designs incorporating disposable components.6 In April of 2022 they issued a statement recommending hospitals and endoscopy facilities transition to duodenoscope designs that include disposable components or to fully disposable duodenoscopes, and in addition stated that duodenoscope manufacturers would no longer market fixed endcap duodenoscopes in the US.7
Innovative Design Solutions
To date, there are six duodenoscopes that incorporate disposable components and have been
approved by the FDA for clinical use. Two single-use duodenoscopes: aScope Duodeno by
Ambu Innovation GmbH and EXALT Model D single-use duodenoscope by Boston Scientific
Corporation, and four duodenoscopes with disposable components: Duodenoscope model ED-
580XT by Fujifilm Corporation, Evis Exera III Duodenoviodescope Olypmpus TJF-Q190V by
Olympus Medical Systems, and Duodenoscope models ED34-i10T2 and ED32-i10T by Pentax
Medical.7
Fully Disposable Duodenoscopes
Early studies have shown that disposable duodenoscopes have a safety and efficacy that is
comparable to reusable duodenoscopes. 5,8-11 A study in 2020 of 6 expert endoscopists comparing EXALT Model D with 3 different reusable duodenoscopes on a benchtop model showed similar completion times and ratings in performing 4 ERCP tasks. 10 Subsequently, a single-arm human case series 5 and a multicenter, prospective randomized trial comparing EXALT Model D to a
reusable duodenoscope found no difference in rates of cannulation, adverse events, need to
cross-over, or need for advanced cannulation techniques between cohorts.8 Slivka et al evaluated
the usability of EXALT Model D in endoscopists with varying levels of ERCP experience and
found good procedural success and high device performance ratings in both cohorts.9 Exalt Model D has also been evaluated internationally with similar success rates.11
Duodenoscopes with Disposable Components
All four of the duodenoscopes with disposable components contain a removable and disposable
end device. Removal of the endcap allows for easier access to the elevator components during
cleaning and less likelihood of persistent bacterial infection. One of these duodenoscopes, ED34-
i10T2 by Pentax Medical, also includes a disposable elevator mechanism.12
A randomized trial of 108 ED-580XT duodenoscopes by Fujifilm Corporation evaluating
bacterial contamination after reprocessing with the cap detached versus in-place showed
significantly less bacterial contamination in the group with the detachable cap.13
Remaining Challenges
Despite the indisputable patient safety benefit associated with single use duodenoscopes, as well
as the FDA statement advising facilities begin moving toward incorporation of disposable
technology, several challenges remain in achieving widespread adoption.
Provider willingness
As with any new technology, there is a learning curve associated with single-use duodenoscopes.
However, widespread proceduralist adoption and embracing of the technology is likely to
improve as new iterations of the single-use scopes become more comparable to reusable scopes, and as future generations of endoscopists learn to perform ERCP using both types of
duodenoscopes from the start.
Cost
The cost implications in adopting new technology must be considered. Bang et al. found that
replacing just one reusable duodenoscope with single-use duodenoscopes at a high-volume
center would cost about 10x more to treat the same number of patients.14 However, another study
looking at cost utility of single-use and partially disposable duodenoscopes compared to reusable
duodenoscopes found that both were more favorable from a cost utility standpoint than single or
double HLD at all infection transmission rates.15 In July 2021, Medicare passed a transitional
pass-through payment for single-use duodenoscopes in Hospital Outpatient Departments and
ASCs.16 This provides a temporary, device specific payment for single-use duodenoscopes in
addition to and beyond the payment for the associated procedure in order to allow facilities to
incorporate the new technology. In addition, private payers are increasingly covering the costs of
single use duodenoscopes.
Implementation
An important challenge in a facilities’ adoption of single-use duodenoscopes is the need to both
create and implement a protocol for integration. A common approach is to start by identifying
patients at highest risk of harm if they were to contract a duodenoscope-related infection and at
highest risk to contaminate a reusable duodenoscope with a drug-resistant organism.16 Daily
multi-disciplinary huddles including a discussion on scopes to be utilized, incorporation of a
protocol checklist into the nursing pre-op process, and the ability to designate use of a single-use
duodenoscope in the electronic record at the time of procedure ordering are possible strategies
for implementation.
Issues encountered in post marketing analysis with the disposable scopes and disposable cap
duodenoscopes have been reported in the MAUDE database between 2018-2021.18 Pertaining to
the disposable duodenoscopes, there were optical problems, difficulty in advancing the
duodenoscope, fluid leak (2 reports), and use-of-device problems. The duodenoscopes with
detachable/disposable caps were still found to have bacterial contamination, issues with device
use (31 reports), detachment/separation of the device, and a crack/dent in the device material.
The reported patient adverse events included tissue injury (63 reports), perforation (8 reports),
and bleeding (7 reports). Critiques of the MAUDE data include voluntary reporting from
physicians which may be under-reporting events and lack of ability to parse out details relating
to these events. However, it is important to note that these newer scopes are not without their
own set of potential issues that must be recognized.
Remaining Opportunities
In addition to the clear benefits of minimizing, or even abolishing, the risk of nosocomial
infection transmission through duodenoscopes, single-use devices allow for exciting
advancements in two major areas: innovation and customization.
Innovation
Traditionally, when a hospital or endoscopy facility purchases reusable scopes, it’s a big capital
investment. Consequently, that practice is unlikely to upgrade when new devices emerge. With
single-use scopes, that investment pressure is diminished; once an upgrade becomes available it
can be put into use immediately. This not only allows for physicians to always have the newest
technology, it also inspires feedback and innovation between physicians and industry. Physicians
are incentivized to participate in product design improvement since they can experience the new
devices in real-time, allowing for rapid technological advancement.
Customization
Reusable duodenoscopes have had to operate on the mantra of ‘one size fits most’ since the
scopes are reused by multiple physicians. Single-use scopes make it possible to tailor scopes
based on both patient factors and physician factors. For example, scope dials can be customized
to fit different hand sizes; scope shaft length can be customized based on patient age, size or
anatomy – longer scopes for altered anatomy patients, shorter scopes for pediatric patients; scope
shaft stiffness and/or diameter can be customized based on patient pathology – stiffer for J-
shaped stomachs, slimmer for partial gastric outlet obstruction.
Conclusion
Endoscope-associated bacterial infections have been increasingly recognized as a significant
patient-safety concern, ultimately leading to an FDA recommendation for all facilities
performing ERCP to transition to disposable duodenoscope technology. While widespread
adoption of this technology faces challenges of cost-effectiveness, implementation, and provider
willingness, the undisputable patient safety benefit in addition to the potential benefits in terms
of innovation and customization may inevitably lead to the extinction of reusable scopes.
However, with new scope designs, other issues may arise and must be acknowledged as these
devices gain more widespread use.
Disclosures
Dr. Tyberg has received consulting fees from Ambu Inc., Boston Scientific and EndoGastric
Solutions.