August 2, 2023 (By Lawrence F Muscarella, PhD. Last update: April 8, 2024) — While novel duodenoscopes with disposable components may reduce the risk of infection for patients, these innovative devices are not failsafe, and can introduce two previously unfamiliar adverse events, FDA acknowledged in a letter earlier this year.
Jump to: Recommendations | Two Adverse Events | FDA Clearances | May 2023 Recall | Bacterial Contamination: A Third Adverse Event | August 2023 Recall | Conclusions/Summary | Timeline | Sponsorship
Highlights:
- FDA issued two safety notices, first in 2019 and then again in 2022, advising endoscopy centers to transition from conventional duodenoscopes, which feature a permanently affixed endcap, to innovative duodenoscopes with disposable components that include a single-use endcap, or to fully disposable duodenoscopes. This federal instruction was in response to documented risks associated with the ineffective cleaning and disinfection of conventional duodenoscope models. The more modern disposable duodenoscope designs are intended either to facilitate or completely eliminate reprocessing.
- During the past decade, many investigations have linked the complex designs of conventional duodenoscopes to outbreaks of antibiotic-resistant bacteria — or “superbugs.” Several of these outbreak investigations reported bacterial contamination of the surfaces in and around the conventional duodenoscope’s fixed endcap, including the elevator mechanism, despite identifying no reprocessing breaches. The older conventional duodenoscope models are no longer sold in the U.S.
- FDA has recently cleared several novel duodenoscope models with a single-use (removable) endcap, as well as completely disposable duodenoscopes. While innovative duodenoscope models with a single-use endcap can reduce the device’s contamination rate, two previously unfamiliar adverse events — mucosal tissue injuries and detachment of the endcap inside the patient — have been reported when using these new models.
- In 2021, two manufacturers voluntarily recalled two duodenoscope models with a single-use endcap to notify customers about the potential for these two adverse events, and to provide guidance to reduce the risks. That same year, this article’s author discussed the risk of these two adverse events, which may have been the first time these two safety concerns were publicized.
- This past March, FDA issued a warning letter to a manufacturer (not to healthcare providers, per se) identifying certain issues with a duodenoscope’s single-use endcap. This published letter appears to have been the first time FDA discussed the risks of mucosal tissue injuries and endcap detachment when using a novel duodenoscope model with a disposable distal cover.
- Two months later, in May, this manufacturer initiated a voluntary recall instructing customers to stop using this novel duodenoscope model’s single-use endcaps with “the original design.” This recall’s notice advised users that consequences of detachment of this single-use endcap could include the risk of aspiration, inhalation, or obstruction.
- This month (August), this manufacturer again voluntarily recalled this novel duodenoscope model with a single-use endcap, although this time the regulatory action was in response to recent reports of infections and positive cultures. While designed to facilitate cleaning, novel duodenoscope models with a single-use endcap do not eliminate the risk of cross-infections.
- Update (February 21, 2024): In addition to initiating recalls in 2021, in May 2023, and in August 2023, the manufacturer issued an urgent device correction letter in December (2023) that again advised users about the risk of the single-use endcap detaching from this novel duodenoscope model during use. Like the recall notification issued seven months earlier, in May (2023), this December letter advised users that detachment of this endcap in the patient’s oral cavity can result in aspiration, airway obstruction, or respiratory distress. The formal recall notice associated with this December letter was posted on-line on February 9, 2024.
- This article provides updated guidance — possibly the most replete list of recommendations — to reduce the risk of mucosal injuries in the upper GI tract and dislodgement of the single-use endcap inside the patient when using a duodenoscope with a single-use endcap. This guidance includes proper training and confirming the single-use endcap is correctly attached to the duodenoscope prior to the procedure, and not using a single-use endcap that has a crack, pinhole or otherwise appears damaged.
Article citation: Muscarella LF. Guidance to Prevent Adverse Events Including Mucosal Injuries When Using Duodenoscopes with a Single-Use Endcap. Discussions in Infection Control. August 2, 2023.
Jump to: Recommendations | Two Adverse Events | FDA Clearances | May 2023 Recall | Bacterial Contamination: A Third Adverse Event | August 2023 Recall | Conclusions/Summary | Timeline |
August 2, 2023 (By Lawrence F Muscarella, PhD. Last update: April 8, 2024) — While novel duodenoscopes with disposable components may reduce the risk of infection for patients, these innovative devices are not failsafe, and can introduce two previously unfamiliar adverse events, FDA acknowledged in a letter earlier this year.
Almost three years ago, FDA began receiving reports of these two particular adverse events occurring during the use of newly introduced duodenoscope models featuring a single-use endcap, an extensive review of the FDA’s medical device database has found.
Some manufacturers may refer to the novel duodenoscope’s single-use endcap instead as a disposable distal cover.
The next year, in the spring of 2021, two manufacturers voluntarily recalled two duodenoscope models of this design type to reduce the risks of these two adverse events, which are unrelated to device contamination and patient infection.
Both manufacturers classified these 2021 recalls as a device correction, such that neither recall required customers to stop using the duodenoscope or its single-use endcap.
That same year, Lawrence F. Muscarella, Ph.D. — who is the author of this article — focused on the risks of these same two adverse events in an independent newspaper intended primarily for gastroenterologists.
That discussion, in 2021, may have been the first time these two adverse events were publicized.
Dr. Muscarella discussed his concerns about these same two safety risks — along with guidance to prevent them — three more times in 2022 (i.e., in April, September, and November), and again earlier this year. FDA has cleared several novel duodenoscope models with disposable components since 2017.
It is my opinion that federal health officials missed opportunities to advise the public about the potential for these two adverse events. A federal safety communication issued last year, for example, did not discuss the FDA’s having previously received adverse event reports describing mucosal tissue injury or endcap detachment inside the patient when using duodenoscope models equipped with a single-use distal cover. — Lawrence F. Muscarella, Ph.D.
This past March, FDA issued a warning letter to a manufacturer that identified certain concerns with the company’s single-use endcap. This letter apparently marked the first time FDA discussed the risk of these two specific adverse events occurring when using a novel duodenoscope model featuring a single-use endcap.
FDA warning letters, like this one, are written to the device’s manufacturer, not to healthcare providers per se. Moreover, federal law apparently does not require patients be informed about the cited device’s safety risks described in the letter.
Two months later, this manufacturer, one of the two companies that had voluntarily recalled a duodenoscope model in the 2021, initiated another voluntary recall. Unlike the earlier recall, however, this May action advised customers to stop using certain lots of this duodenoscope model’s single-use endcap.
This article provides updated guidance — possibly the most replete list of recommendations — to reduce the risk of these two adverse events.
This guidance includes confirming the single-use endcap is correctly attached to the duodenoscope prior to the procedure, and not using a single-use endcap that has a crack, pinhole or otherwise appears damaged.
Endoscopic retrograde cholangiopancreatography is an upper gastrointestinal procedure used to view, diagnose and treat diseases and conditions in the bile and pancreatic ducts. As many as 500,000 to 660,000 ERCP procedures are performed annually in the U.S.
Duodenoscopes feature a cable-actuated elevator mechanism that physicians use during ERCP to manipulate and angulate endoscopic accessories passed through the instrument channel. The endcap, which surrounds this elevator mechanism, is located at the duodenoscope’s distal end.
Forensic Case Reviews, Adverse Event Analyses, and Expert Guidance in the Causes and Prevention of Hospital Infections: LFM-Healthcare Solutions, LLC provides medical expertise for healthcare facilities, device manufacturers and the public, specializing in healthcare-associated infections linked to contaminated reusable medical equipment.
FDA: Transition to safer design
First in 2019 and then a second time in 2022, FDA issued two safety alerts advising manufacturers and health care facilities to begin replacing conventional duodenoscopes, which feature a permanently affixed endcap, with more modern duodenoscope designs equipped with disposable components that include a single-use (removable) endcap, or to use completely disposable duodenoscopes.
This federal instruction was in response to well-publicized difficulties effectively cleaning and disinfecting duodenoscopes with a fixed endcap. Inadequately reprocessed endoscopes can pose an increased risk of persistent device contamination and patient infection with associated patient morbidity and mortality.[1]
This article provides updated guidance — possibly the most replete list of published recommendations — to reduce the risk of these two adverse events during use of duodenoscope models featuring a disposable distal cover. — Lawrence F Muscarella, PhD
Exemplifying these reprocessing challenges, more than a dozen outbreaks of antibiotic-resistant bacteria, or “superbugs,” have been linked the past decade, worldwide, to duodenoscopes featuring this older, fixed (immovable) endcap design.[2]
Investigations of several of these outbreaks reported that conventional duodenoscopes, particularly the complex surfaces in and around the fixed endcap including the elevator mechanism, could remain contaminated with multidrug-resistant bacteria despite identifying no reprocessing breaches.[1,2]
These conventional duodenoscope models (with a fixed endcap) are no longer sold in the U.S., although reports in the FDA’s adverse events database — also known as the “MAUDE” database — suggest some of these models may remain in use in other countries.
For example, FDA received a report in May linking a conventional duodenoscope to an outbreak, apparently in Europe, of VIM-producing Pseudomonas aeruginosa, which is a type of superbug resistant to “last resort” antibiotics. According to the FDA report, the reprocessing steps were found to be adequate.
These newly introduced disposable duodenoscope designs are intended either to facilitate or completely eliminate reprocessing.
The duodenoscope’s endcaps may be made of plastic, rubber, silicone, or other soft materials “to cover the metal edges on duodenoscope distal ends to prevent tissue injury from the metal edges,” according to FDA.
Unlike conventional duodenoscopes whose fixed endcaps are “permanently glued to the metal edges around the distal end,” single-use endcaps remain attached to the duodenoscope “by tension,” FDA has also stated.
One of these innovative duodenoscope models with a single-use distal cap was cleared in September 2017. The same manufacturer received a FDA clearance in November 2019 for a different novel model that features the elevator mechanism designed into the single-use endcap.
Another manufacturer’s duodenoscope with a single-use endcap received three FDA clearances, first in January 2020 and then twice again in December 2020 and May 2022.
FDA cleared the first entirely disposable duodenoscope in December 2019. A second fully disposable model, marketed by another company, was cleared a month later in July 2020.
While successfully reducing one identified safety risk, a redesigned medical device can unwittingly introduce another safety concern, which underscores the importance of the comprehensive validation and verification of a medical device’s design prior to marketing and clinical use. — Lawrence F Muscarella, PhD
A recently published technology report listed all of the duodenoscope models that FDA had cleared (as of 2021) featuring a single-use endcap, or that are fully disposable. (For historical clarity, FDA first cleared duodenoscope models featuring a removable distal cover more than 20 years ago, in 1996 and 1998.)
This article includes a timeline of events that lists the dates of these FDA clearances along with other dates related to the use of duodenoscope models featuring a single-use endcap.
Two adverse events, risk of complications
In late 2019, FDA began receiving reports, primarily from the manufacturers, describing these two previously unfamiliar adverse events occurring during clinical use of duodenoscope models featuring a single-use endcap:
- mucosal injuries, which include reports of mucosal tissue becoming caught in the duodenoscope’s disposable distal cover; and/or
- the disposable distal cover inadvertently becoming detached from the duodenoscope and falling off inside the patient.
Factors that can cause, contribute to, or increase the risk of these two adverse events reportedly include improper attachment of the endcap to the duodenoscope’s distal end, activating the suction feature during withdrawal of the duodenoscope, and use of a cracked or otherwise damaged endcap.
As described in FDA’s MAUDE database, these two adverse events can be associated with a number of clinical complications, including:
- mucosal tissue injury, sometimes with bleeding (possibly requiring use of a hemostatic clip);
- performing a second endoscopic procedure (e.g., esophagogastroduodenoscopy, or EGD) after ERCP to evaluate visually whether a detached, missing distal cover had fallen off in the patient’s gastrointestinal tract;
- performing unplanned bronchoscopy (after ERCP) to identify whether a dislodged disposable endcap had fallen off into the patient’s respiratory tract; (text added April 8, 2024);
- aspiration, inhalation or respiratory distress (e.g., a patient “coughing up” the detached endcap) if the endcap were to fall off in the patient’s airways or oral cavity and is not promptly removed;
- prolonging the time to complete the endoscopic procedure (e.g., 20 minutes) and/or extending the patient’s sedation and/or anesthesia time while searching for, and attempting to remove, the detached endcap (e.g., using a grasping forceps) from inside the patient (e.g., in the patient’s mouth, stomach, or duodenum); and/or
- performing an x-ray or a computerized tomography (CT) scan of the patient’s abdomen and/or pelvis in an effort to locate the detached distal end cap. [Note: In a few cases, the respective FDA report states that the endcap could not be located and retrieved. One report observes that the single-use distal cover may be “difficult to locate when they fall off inside the patient as they are not visible on x-rays or CT scans,” although this report’s claim could not be independently verified.]
At least two manufacturers (Manufacturer X and Manufacturer Y) have addressed some of these complications to reduce the risks. This article did not analyze and review the frequency of these complications occurring per ERCP procedure performed.
While both the FDA’s MAUDE database and recall database suggest these two adverse events are not unique to a single manufacturer’s novel duodenoscope model with a single-use endcap, this article could not assess whether any one duodenoscope model might be more (or less) prone, per ERCP procedure performed, to either adverse event, due to insufficient data at this time.
Early FDA reports
Each of the three manufacturers that markets new, novel duodenoscope models in the U.S. featuring a single-use endcap (or disposable distal cover) began reporting to FDA one or both of these adverse events more than three years ago, in late 2019 or early 2020. For example:
• Manufacturer X: Some of the initial cases submitted to FDA describing the potential occurrence of mucosal injuries during use of this manufacturer’s novel duodenoscope model were reported in December 2019 and March 2020.
Regarding the second adverse event, some of the initial reports describing the single-use endcap from this manufacturer’s same novel duodenoscope model becoming detached and falling off inside the patient were submitted to FDA in June 2019 and April 2020.
• Manufacturer Y: Some of the initial cases submitted to FDA similarly describing potential mucosal injury when using a second manufacturer’s novel duodenoscope model were reported in August 2020 and September 2020.
Some of the initial reports describing this other duodenoscope model’s single-use endcap (with disposable elevator) becoming detached and falling off inside the patient were submitted to FDA in March 2020 and September 2020.
• Manufacturer Z: Some of the initial cases submitted to FDA describing the single-use endcap of a third manufacturer’s novel duodenoscope model becoming detached and falling off inside the patient were reported in January 2020 and September 2020.
Reports describing mucosal injury during use of this third manufacturer’s duodenoscope model featuring a single-use endcap had not been reported to FDA until this year.
(This article acknowledges the FDA’s statement that while the MAUDE’s medical device reports “are a valuable source of information, this passive surveillance system has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data.”
Dr. Muscarella’s related peer-reviewed articles:
- “Bronchoscope-Related ‘Superbug’ Infections” (Chest 2020 Feb;157(2):454-469)
- “Use of ethylene-oxide gas sterilisation to terminate multidrug-resistant bacterial outbreaks linked to duodenoscopes” (BMJ Open Gastro 2019;6:e000282)
- “Risk of transmission of carbapenem-resistant Enterobacteriaceae and related ‘superbugs’ during gastrointestinal endoscopy” (World J Gastrointest Endosc 2014 Oct 16; 6(10): 457–474)
More recent FDA reports
More recently, FDA also received reports this year describing one or both of these two once-unfamiliar adverse events occurring during use of different duodenoscope models with a single-use endcap, including last month. For example:
• Manufacturer X: FDA received a report in May stating that a single-use distal cover became dislodged and fell into a patient’s airway. According to the report, the patient “required intubation and the cover was then removed” with the patient sustaining “some mucosal irritation.”
• Manufacturer Y: FDA received a report in March stating that during ERCP a physician linked use of this duodenoscope model with a single-use endcap (and elevator) to a small laceration.
In February, FDA received a report stating that the single-use endcap “had become detached from the distal end of the duodenoscope and remained in the lungs.” The report noted that the duodenoscope had been “mistakenly inserted into the trachea.”
• Manufacturer Z: FDA received a report in June stating that during ERCP the distal end cap “detached from the distal end of a duodenoscope and fell into the patient’s oral cavity. The cap was extracted by performing an endoscopy.”
Update (October 9, 2023): Regarding the second adverse event, FDA received a report in September (2023) describing tissue injury — specifically, perforation of a patient’s esophagus — during use of this third manufacturer’s novel duodenoscope.
Unlike the other two manufacturers’ novel duodenoscope model, this third manufacturer’s duodenoscope has not been recalled, to date, in response to either of these two adverse events.
Details of a 2021 duodenoscope recall
One of the two manufacturers that in the spring of 2021 issued a (class II) recall of a duodenoscope model with a single-use endcap classified the action as a voluntary correction, not as a device removal. Consequently, hospitals and endoscopy facilities could continue using the duodenoscope or its accompanying endcap, according to the terms of the recall.
The recall’s notice referred to a related letter the manufacturer had issued a month earlier informing users of the duodenoscope about reports of mucosal injuries in the esophagus, stomach and duodenum.
A on-line safety notice, contemporaneously dated February 17, 2021, provided instructions to reduce the risks not only of these types of mucosal injuries, but also of the single-use endcap falling off of the duodenoscope inside the patient during ERCP.
Details of a second 2021 duodenoscope recall
The second manufacturer that also issued a voluntary (class II) recall of a duodenoscope model in 2021 similarly classified the action as a device correction. This device’s single-use endcap includes a disposable elevator mechanism.
According to this recall’s notice, the manufacturer initiated this regulatory measure to inform customers that both this duodenoscope and single-use endcap’s instructions had been updated to notify users of the risks of the single-use endcap “unexpectedly becoming detached during a procedure.”
The recall notice further advised that detachment of the endcap could result in “mucosal injury, lacerations, or bleeding of the patient,” as well as “aspiration” (as the other manufacturer’s recall in 2021 had also advised) if the endcap were to fall off in the patient’s oral cavity.
This recall, like the other manufacturer’s recall issued in 2021, refers to a related correction notice issued a month earlier, in April 2021, advising users of the potential risk of these two adverse events.
FDA warning letter, a May (2023) recall
The warning letter FDA wrote in March to a manufacturer of novel duodenoscope models citing certain quality and safety issues with the company’s single-use endcap was apparently prompted by the findings of an inspection FDA had performed of the company four months earlier, in November (2022), according to the warning letter.
This article’s review did not identify an instance prior to this warning letter, dated March 15, 2023, when federal health officials had addressed concerns about mucosal injuries or detachment of the single-use endcap during use of a duodenoscope featuring this disposable component. (Although such instances may be available, they were not identified during this review.)
Two months after FDA issued this March warning letter, the manufacturer voluntarily initiated a (class II) recall, in May. Unlike the manufacturer’s previous 2021 recall of the duodenoscope, however, this year’s recall instructed customers to stop using the duodenoscope’s single-use distal covers with “the original design” and to return them to the company (under the terms of this recall).
The manufacturer’s voluntary recall earlier this year, in May, instructed customers to stop using the duodenoscope’s single-use endcaps with the original design, which can be identified by a lot number of “less than H2530.”
The recalled endcaps with the original design can be identified by an item code or by lot numbers that are “less than H2530,” according to the manufacturer’s recall notice. (The most recent clearance associated with this manufacturer’s duodenoscope and single-use endcap was almost a year ago, in May 2022.)
An on-line safety notice, dated one month earlier on April 24, 2023, provided additional information relating to this recall. The notice reiterates the importance of inspecting and correctly attaching the endcap to the duodenoscope prior to the procedure, while also advising that the clinical consequences of a detached or cracked cover could include “the risk of aspiration, inhalation, tissue damage or bleeding,” as well as “burns from an uncovered distal end.”
Last year, FDA had issued two other warning letters to the company and a related entity in November and December. Both letters raise reasonable questions for the reader about the regulatory status of the firm’s “sterile and non-sterile Endoscopes” and “gastrointestinal and surgical endoscopes,” respectively.
According to the manufacturer’s May recall, this single-use endcap’s “original design” — like the endcap’s incorrect attachment, the use of a cracked endcap, and/or activating the suction feature during withdrawal of the duodenoscope — can increase the risk of mucosal injury and/or the single-use endcap becoming detached and falling off inside the patient.
A redesigned endcap, recent FDA reports
Recent FDA adverse event reports provide additional insight into FDA’s March warning letter, the manufacturer’s voluntary recall, in May, of the single-use endcap with the original design, and into the safety of these novel duodenoscope components.
In May, for example, FDA received a report from a hospital describing detachment of the endcap in the patient’s mouth due to inadvertent contact with the bite block upon removal of the duodenoscope (without further incident, according to the report). The hospital has been using the “redesigned” distal cover, the report states.
The FDA report identifies the redesigned distal cover that the facility has been using, and which the facility also refers to in the report as the “second generation” distal cover, by the lot numbers H2624 and H2714.
The redesigned single-use endcaps can be identified by a lot number of H2530 or higher, according to the manufacturer’s recall and other related documentation.
This report’s identified lot numbers are consistent with an on-line document’s listing of the “new design” of the single-use endcap as featuring a lot number of “H2530 or higher.”
FDA appears to have cleared the original single-use endcap (i.e., lot numbers of less than H2530) along with the duodenoscope in January 2020. FDA’s premarket clearance database suggests the manufacturer’s redesigned endcap (i.e., lot numbers of H2530 or higher) was cleared two years later, in May 2022. (In apparent agreement, the manufacturer’s narrative provided in an FDA report filed in June states that the “distal cover had undergone a design change in May 2022.”)
One of the earliest cases this article identified apparently involving a redesigned single-use endcap is detailed in a report submitted to FDA last January describing an esophageal tear (with no perforation). According to the report, the endcap’s lot number was H2623.
An adverse event report FDA received in June describing detachment of the single-use endcap during the ERCP procedure apparently identifies the single-use endcap’s lot number as H2713, which would be a redesigned endcap (according to the previous month’s May recall and other related documentation). This FDA report notes that “the operator felt that the distal cover had been placed correctly without resistance or difficulty and that he felt the cover ‘snap’ into place.”
A related on-line notice states that the manufacturer has observed a decrease in the number of complaints of mucosal injury and endcap detachment with the redesigned distal cover.
Nevertheless, a related on-line notice states that the manufacturer “redesigned the distal cover and has observed a decrease in the referenced complaints,” adding that the “recall does not impact the new distal cover design.”
FDA’s March warning letter to the manufacturer does not clarify the lot numbers of the impacted single-use endcaps.
Forensic Investigations, Case Reviews, Expert Guidance in the Causes and Prevention of Hospital Infections: LFM-Healthcare Solutions, LLC provides medical expertise for healthcare facilities, device manufacturers and the public, specializing in healthcare-associated infections linked to contaminated reusable medical equipment. Value-oriented advice with years of experience and trust.
Bacterial contamination: a 3rd adverse event
This article focuses primarily on the prevention of two specific, once-unfamiliar adverse events — mucosal injuries of the GI tract, and detachment of the duodenoscope’s single-use endcap inside the patient– during use of duodenoscope models featuring a disposable distal cover.
However, some studies have assessed the risk of a third adverse event — bacterial contamination — during use of these types of novel duodenoscope models.
For example, Pasricha (2022) reviewed FDA reports for 2021 discussing patient injuries associated with these novel duodenoscope models that included, in addition to mucosal injuries and endcap detachments, device contamination.[3]
Based on that review, Pasricha (2022) reported that duodenoscope models with a single-use endcap “may actually be worse in preventing contamination” possibly because “the new duodenoscopes have cap attachment points that create additional crevasses beyond the elevator that must be manually cleaned.”[3]
Cases describing bacterial contamination of duodenoscopes with a disposable distal cover were reported to FDA this year.
For example, a May FDA report states that the distal end of a duodenoscope with a single-use endcap, disinfected using an automated endoscope reprocessor, “was microbiologically cultured and tested positive” for Escherichia coli that was “too numerous to count.”
Periodic retraining of clinical staff to ensure proper attachment of the single-use endcap to the duodenoscope is recommended. — Lawrence F Muscarella, PhD
Ofosu et al. (2022), who analyzed adverse event reports submitted to FDA between July 2018 and June 2021 that involved novel disposable duodenoscope designs, identified 53 reports related to bacterial contamination involving duodenoscopes with “detachable/disposable caps.”[4]
In apparent contrast, however, Forbes et al. (2023) performed a parallel-arm multicenter randomized clinical trial at 2 tertiary ERCP centers in Canada that found, seemingly in agreement with some of FDA’s conclusions, that — at least for models featuring a single-use endcap with a disposable elevator — the duodenoscope “exhibited reduced contamination following high-level disinfection compared with standard scope designs, without affecting the technical performance and safety of ERCP.”[5]
This review article’s analysis did not independently assess or verify the findings of Pasricha’s (2022), Ofosu et al. (2022) or Forbes et al. (2023).
Update (August 31, 2023): The manufacturer that had voluntarily recalled a novel duodenoscope model in March 2021 to reduce the risk of mucosal injuries and the duodenoscope’s single-use endcap falling off inside the patient has again recalled the device, but for another risk.
This voluntary action is “being initiated due to the firm becoming aware of and FDA inquiring about recent reports of infections and positive cultures,” according to the recall notice the manufacturer issued this month, on August 28, 2023. The manufacturer has classified this (class II) recall as a voluntary corrective action, not as a device removal.
The August recall notice reminds “users to closely follow” this duodenoscope’s reprocessing instructions while also advising that this device’s reprocessing manual has been updated in an effort “to improve comprehension of existing reprocessing steps.” The notice also clarifies that the “manual is available on the customer web portal and paper copies, along with wall charts, are available to be mailed to your facility.”
Similar to the other recalls, this recall’s August notice refers to a related urgent notification letter, dated the previous month on July 27, 2023, that the manufacturer wrote to inform “consignees” (e.g., users) about this recall.
Both this August recall notice and July letter discuss the requirement that the manufacturer inspect and perform maintenance of the duodenoscope’s forceps elevator mechanism “once a year or every 100 reprocessing cycles” (whichever occurs sooner). According to an online document dated July 27, 2023, which provides additional details about this voluntary recall, the purpose of the inspection is to ensure the duodenoscope is “properly functioning.”
Providing additional guidance, the August recall notice “encourages consignees to consider incorporating voluntary routine microbiologic surveillance of endoscops (sic) as part of their quality improvement/assurance efforts.”
An FDA report filed last November linked three bacterial infections to three procedures performed in a U.S. facility using a single duodenoscope device with a disposable endcap.
Update: A December (2023) letter, (February 2024) recall
In addition to initiating recalls in 2021, in May 2023, and in August 2023, the manufacturer issued an urgent device correction letter in December (2023) that once again advised users about the risk of the single-use endcap detaching from this novel duodenoscope model during use.
Like the recall notification issued seven months earlier, this December letter advised users that detachment of this endcap in the patient’s oral cavity can result in aspiration, airway obstruction, or respiratory distress. The formal recall notice associated with the December 2023 urgent correction letter was posted on-line two months later on February 9, 2024.
The following set of recommendations is provided to reduce the risk of mucosal tissue injuries and endcap detachment when using a novel duodenoscope featuring a single-use endcap.
Prior to adopting these measures, however, the medical facility is encouraged to review the duodenoscope’s operator’s manual, including the reprocessing instructions, to verify the appropriateness and effectiveness of each measure. Not all of these recommendations necessarily apply to (or are appropriate for) every marketed duodenoscope model with a single-use endcap.
A — Review the duodenoscope’s IFUs and related recall notices (if applicable)
- Review the duodenoscope’s instructions for use (“IFUs”) and related documentation for the proper visual inspection, correct manual attachment, and safe use of the single-use endcap (which may include a disposable elevator, depending on the manufacturer).
- Reviewing the IFUs for the single-use endcap, separate from the duodenoscope model’s IFUs, is recommended when applicable.
- Review and understand the instructions of any applicable device recalls.
- Consider periodically contacting the manufacturer, as warranted, for updated guidance to further reduce the risk of mucosal injuries and endcap detachment when using a duodenoscope model with a single-use distal cover.
- As instructed by the manufacturer, do not use the single-use endcap recalled in May featuring the “original design.” Return the endcap to the manufacturer (per the terms of the recall’s instructions).
- The recalled endcaps can be identified by an item code or lot numbers that are “less than H2530,” according to the manufacturer.
- The manufacturer has reported observing “a decrease” in the number (not an elimination) of compliants (i.e., mucosal injury, the endcap becoming cracked and/or the endcap’s detachment from the endoscope) with the “redesigned” single-use distal cover (whose lot numbers are H2530 or above).
- Reports submitted to FDA describe disposable endcaps with a lot number above H2530 — for example, H2913, H3125 or H3307: (i) becoming detached from the endoscope, sometimes inside the patient; or (ii) possibly causing a tear or laceration to tissues in the upper GI tract.
- Review and strictly follow the novel duodenoscope’s reprocessing instructions to ensure effective cleaning.
- Contact the manufacturer (if warranted) to ensure use of the most current, up-to-date reprocessing manual.
- While use of the new duodenoscope models with a single-use endcap “can reduce the risk of infection for patients, compared to the older fixed endcap duodenoscope models,” recent reports have linked a model to infections and positive cultures. For exmaple:
- A November 2022 FDA report linked a novel duodenoscope design to three patient infections in the U.S.
- A January 2024 FDA report linked a contaminated novel duodenoscope device to possible cross-infection, also in the U.S.
- While use of the new duodenoscope models with a single-use endcap “can reduce the risk of infection for patients, compared to the older fixed endcap duodenoscope models,” recent reports have linked a model to infections and positive cultures. For exmaple:
- Perform periodic audits to confirm adequate training and compliance with these reprocessing instructions.
- The manufacturer of a novel duodenoscope model recommends periodic inspection of the the forceps elevator mechanism. Refer to the model’s instructions for additional details and futher clarification.
- Contact the manufacturer (if warranted) to ensure use of the most current, up-to-date reprocessing manual.
B — More disposable endcap guidance
- Confirm that the single-use endcap is correctly attached to the duodenoscope prior to the ERCP procedure (as the instructed by the manufacturer).
- Verify that the attached endcap is secure and not loose, slipping off, and/or its attachment visually misaligned. A manufacturer has published visual aids to assist with proper attachment.
- Do not use the duodenoscope if the single-use endcap cannot be properly and securely attached to the duodenoscope’s distal end.
- Replacing the endcap with a new endcap may be necessary for proper attachment.
- Consider watching instructive on-line videos for properly attaching the disposable endcap to the duodenoscope. On-line videos may be available for different novel duodenoscope models.
- Upon removal from its packaging, visually inspect the single-use endcap for cracks, damage, deformities, or other irregularities prior to the ERCP procedure (as instructed by the manufacturer).
- Do not use a single-use endcap that has a crack, pinhole or otherwise appears damaged.
- Replace the damaged endcap with a new one prior to the procedure.
- FDA reports and some manufacturer documentation suggest a cracked or damaged endcap — like an improperly attached endcap — could increase the risk of:
- mucosal injuries (with or without bleeding);
- the endcap detaching from the duodenoscope and falling off inside the patient (e.g., into the oral cavity or respiratory tract, in addition to the GI tract); and/or, among other complications,
- “thermal injury due to electric current leaks from cracks or pinholes when high-frequency cauterization treatment is performed,” according to a manufacturer.
- A manufacturer has cautioned users not to apply “anti-fogging products, olive oil, or products containing petroleum-based substances (e.g., Vaseline®) to the distal cover or the endoscope” as such products may cause “cracks in the distal cover” that can facilitate the cover’s detachment.
- Do not use a single-use endcap that has a crack, pinhole or otherwise appears damaged.
- Upon completion of the ERCP procedure, again visually inspect the duodenoscope’s distal end.
- If mucosal tissue is observed at the distal end (or a mucosal injury is otherwise suspected), evaluate whether a second endoscopic procedure (e.g., EGD) may be necessary t0 visualize and assess the patient’s upper GI tract for potential injury that might require medical intervention, a manufacturer recommends.
- Similarly, if the disposable endcap is found not to be attached to the duodenoscope’s distal end after completion of the ERCP procedure, evaluate whether performing a second endoscopic procedure is necessary to try to locate and retrieve the detached endcap.
~ Recommendations continued below ~
Forensic Case Reviews, Adverse Event Analyses, and Expert Guidance in the Causes and Prevention of Hospital Infections: LFM-Healthcare Solutions, LLC provides medical expertise for healthcare facilities, device manufacturers and the public, specializing in healthcare-associated infections linked to contaminated reusable medical equipment.
~ Recommendations continued from above ~
C — Suctioning during ERCP
- Apply the duodenoscope’s suction function “intermittently” when withdrawing a duodenoscope featuring a single-use endcap, a manufacturer recommends.
- Perform suctioning when the duodenoscope is stationary inside the patient’s GI tract, the manufacturer also recommends.
- Applying suction when this novel type of duodenoscope is “in motion” (e.g., during withdrawal of the duodenoscope) could increase the risk of mucosal tissue injuries, according to this manufacturer.
- Consider watching manufacturer videos for more guidance to improve safety when suctioning.
- Perform suctioning when the duodenoscope is stationary inside the patient’s GI tract, the manufacturer also recommends.
- Do not operate the suction feature when the duodenoscope’s distal end is too close to (or pressed up against) the mucosa’s surface, one manufacturer advises, to avoid the tissue becoming “sucked into” the single-use endcap and torn.
- Ensure the duodenoscope’s suctioning feature is functioning properly and within the manufacturer’s specifications.
D — Other related guidance
- Do not reuse a single-use endcap on more than one patient, as this practice could pose safety concerns including an increased risk of: (i) cross-infection, and (ii) wear and tear to the cap, causing it to become more prone to dislodgement and to falling off inside the patient during the procedure.
- Discard the endcap after each patient use. Do not reprocess it.
- When removing the duodenoscope from the patient’s mouth, use care to ensure that the bite block or mouthpiece (if present) does not inadvertently cause the single-use endcap to become detached and to fall off into the patient’s oral cavity.
- Similarly, use care when inserting or removing the duodenoscope via a laparoscopic trocar to prevent physical stresses that could result in inadvertent detachment of the single-use endcap. (FDA received a report in April stating that the “cap apparently came off” during ERCP as the duodenoscope “was being withdrawn through the [laparoscopy] trocar.”)
- Consider discussing with the manufacturer whether the duodenoscope’s single-use endcap might possibly be marked with a radiopaque material to facilitate visualization and its detection (e.g., using x-ray imaging) if the endcap were to become detached inside the patient.
- Consider routine microbiologic surveillance (i.e., sampling and culturing) of the novel duodenoscope (as warranted) to improve safety (as a manufacturer has advised).
- Medical facilities in other countries that continue to use conventional duodenoscopes with a fixed endcap may consider transitioning to models featuring disposable components, or to entirely disposable duodenoscopes.
In response to well-publicized difficulties effectively cleaning and disinfecting duodenoscopes with a fixed endcap, FDA has advised health care facilities to transition to more modern duodenoscope designs equipped with disposable components that include a removable single-use endcap, or to use completely disposable duodenoscopes. These disposable designs are intended either to facilitate or completely eliminate reprocessing.
While post-market surveillance data suggest that novel duodenoscope models with a single-use endcap can reduce the risk of infection for patients, these devices are not failsafe. Cases of mucosal tissue injuries and detachment of the single-use endcap inside the patient have been reported, beginning in late 2019 and during 2023 too, when using these novel duodenoscope designs to perform ERCP.
Clinical complications resulting from these two adverse events can include mucosal bleeding; aspiration, inhalation, or respiratory distress; performing a second endoscopic procedure to locate and retrieve the detached endcap; a delay in the procedure’s completion time and/or the general anesthesia or sedation time; and performing an x-ray or CT scan in an effort to locate the endcap’s position inside the body.
It is this author’s opinion that federal health officials missed opportunities to advise the public about the risk of these two adverse events. For example, a federal safety communication issued in 2022 did not discuss FDA’s having previously received adverse event reports describing mucosal tissue injury or endcap detachment inside the patient (e.g., in the airways) when using duodenoscope models equipped with a disposable distal endcap.
This past March, FDA issued a letter to a manufacturer that identified certain quality and safety issues with the duodenoscope’s single-use endcap. This letter appears to be the first time FDA addressed the risks of these two adverse events occurring when using a duodenoscope with a single-use endcap.
However, FDA warning letters, like this March one, are written to the device’s manufacturer, not to healthcare providers per se. Federal law apparently does not require patients be notified about a device’s safety risks described in an FDA warning letter.
Two months after receiving this letter, the manufacturer initiated a voluntary recall, in May, that instructed customers to stop using the duodenoscope’s single-use endcaps with “the original design.” A related on-line notice reports that the manufacturer has observed a decrease in the number of complaints describing mucosal injury and endcap detachment with the redesigned distal cover.
Indeed, recent FDA reports describe occurrences of these adverse events with the redesigned endcap, suggesting that this article’s provided recommendations and guidance are not exclusive only to the recalled endcap, and can also be applied to other manufacturers’ endcaps (as warranted).
Incorrect attachment of the endcap to the duodenoscope’s distal end, use of a cracked endcap, and/or activating the suction feature during withdrawal of the duodenoscope can increase the risk of mucosal injury and/or of this single-use endcap falling off the duodenoscope inside the patient.
This article’s research indicates that while successfully reducing one identified safety risk, a redesigned medical device or accessory can unwittingly introduce one or more other safety concerns, which underscores the importance of the comprehensive validation and verification of a medical device’s design prior to marketing and clinical use.
While this article’s review of the FDA’s MAUDE and recall databases suggest that mucosal injuries and endcap detachment are not unique to one manufacturer’s duodenoscope model with a disposable distal cover, the data are currently insufficient to evaluate whether any one model is more prone than another to either adverse event occurring per ERCP procedure performed.
Novel duodenoscope models with a single-use endcap are designed to facilitate cleaning and reduce the device’s contamination rate; however, they do not eliminate the risk of cross-infections. Strict attention to the manufacturer’s reprocessing instructions of all duodenoscope models is critical to prevent infections.
In August, one of the two manufacturers that had voluntarily recalled a novel duodenoscope model in March 2021 (to reduce the risk of mucosal injuries in the upper GI tract and/or the duodenoscope’s single-use endcap falling off inside the patient) again recalled the duodenoscope, this time in response to recent reports of infections and positive cultures.
This article provides several recommendations to reduce the risk primarily of mucosal injuries and endcap detachment when using a innovative duodenoscope model featuring a disposable distal cover.
These recommendations include: reviewing and ensuring compliance with the novel duodenoscope’s most up-to-date operating instructions, reprocessing manual, and any applicable recall notices; periodic training of clinical staff (as warranted) to ensure proper attachment of the single-use endcap to the duodenoscope prior to the ERCP procedure (as the instructed by the manufacturer); and not using a single-use endcap that has a crack, pinhole or otherwise appears damaged.
Final remarks
Not all of this article’s recommendations necessarily apply to (or are appropriate for) every marketed duodenoscope model with a single-use endcap.
It is acknowledged that while FDA has concluded that the MAUDE database’s medical device reports “are a valuable source of information, this passive surveillance system has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data.”
This article acknowledges that linking or associating an endoscope with infection does not confirm the endoscope necessarily contributed to or caused the infections, as one or more other unrelated factors could be, in part or solely, responsible. Additional data would be required to conclude more definitively whether a contaminated device caused an infection.
For its part, a manufacturer may state in an FDA report, in effect, that the “definitive cause of the reported events could not be established,” suggesting that more data may be necessary to confirm more definitively whether the duodenoscope was the cause of the harm.
- 1996 — 1998: FDA clears two duodenoscope models featuring a removable distal cover.
- 2014: Centers for Disease Control and Prevention (CDC) publishes an investigation of a “superbug” outbreak linked to exposure to a conventional duodenoscope model with a fixed endcap. No reprocessing lapses were identified[1]
- 2017: FDA clears the first new, novel duodenoscope model featuring a disposable endcap.
- 2019 (August): FDA issues the first of two safety alerts recommending manufacturers and healthcare facilities transition to new, novel disposable duodenoscope designs.
- 2019 (December): FDA cleared the first fully disposable duodenoscope.
- 2019, 2020: FDA began receiving adverse event reports describing mucosal injuries and dislodgement of the single-use endcap inside the patient during use of one of the recently cleared novel duodenoscope designs with a disposable distal cover.
- 2021 (March): A manufacturer voluntarily recalled a novel duodenoscope model with a single-use endcap to reduce the risk of these two adverse events.
- 2021 (May): A second manufacturer similarly voluntarily recalled a novel duodenoscope with a single-use endcap (and disposable elevator) to reduce the risk of these two adverse events.
- 2021 (July): Lawrence F. Muscarella, Ph.D., who is the author of this review article, highlighted the risk of mucosal injuries and endcap dislodgement during use of a novel duodenoscope design with a single-use endcap.
- 2022 (April): Dr. Muscarella again highlighted the risk of these two adverse events in another publication.
- 2022 (June): FDA issued a second safety alert recommending transition to use of new, novel disposable duodenoscope designs. This federal safety communication did not discuss the risks of mucosal tissue injury or endcap detachment when using duodenoscope models equipped with a disposable endcap.
- 2022 (November): FDA issues a warning letter to a duodenoscope manufacturer that raises questions about the quality of the firm’s endoscopes, which could affect safety.
- 2022 (December): FDA issues a warning letter to a duodenoscope manufacturer that raises questions about the firm’s quality practices.
- 2023 (March): FDA issues a warning letter to a manufacturer that identified certain quality and safety concerns with a duodenoscope’s single-use endcap. The letter appears to be the first time FDA wrote about the risks of mucosal injuries and endcap dislodgement inside the patient during use of a novel duodenoscope model with a single-use end cover. Further, this manufacturer was one of the two that had recalled a novel duodenoscope model (with a single-use endcap) two years earlier, in 2021, due to reports of these same two adverse events.
- Note: This FDA letter stated that: (1) the company “manufactures endoscopes and endoscope accessories including, Single-Use Distal Covers for Duodenoscopes and Single-Use Suction Valve Accessories for Bronchoscopes”; (2) “these devices are adulterated within the meaning of section 501(h) of the Act, 21 U.S.C. § 351(h)”; and (3) the company’s single-use distal cover devices “are misbranded under section 502(t)(2) of the Act, 21 U.S.C. § 352(t)(2).”
- 2023 (April): Dr. Muscarella again highlighted the risk of mucosal injuries and endcap dislodgement during use of a novel duodenoscope design with a single-use endcap in another publication.
- 2023 (May): In the wake of the FDA’s March warning letter, the manufacturer initiated a voluntary recall that instructed customers to stop using the duodenoscope’s single-use endcaps with the “original design.“
- 2023 (May): An FDA report linked a conventional duodenoscope with a fixed endcap, used apparently by a medical facility in Europe, to a superbug outbreak. No reprocessing lapses were reported.
- 2023 (August): The manufacturer that had voluntarily recalled a novel duodenoscope model in 2021 (to reduce the risk of mucosal injuries and/or dislodgement of the single-use endcap inside the patient) again recalled this model, this time in response to recent reports of a third adverse event: infections and positive cultures.
- Update — 2023 (December): This same manufacturer issued an urgent device correction letter that, again, advised users of the risk of the single-use endcap detaching from this novel duodenoscope model during use. Like the recall notification issued seven months earlier, in May (2023), for the single-use endcap, this December letter again advises users that detachment of this endcap in the patient’s oral cavity can result in aspiration, airway obstruction, or respiratory distress.
- Update — 2024 (February): The formal recall notice associated with the December 2023 urgent correction letter was posted on-line on February 9, 2024.
References
- Epstein L, et al. New Delhi metallo-β-lactamase–producing carbapenem-resistant Escherichia coli associated with exposure to duodenoscopes.
- Muscarella LF. Use of ethylene-oxide gas sterilisation to terminate multidrug-resistant bacterial outbreaks linked to duodenoscopes. BMJ Open Gastro 2019;6:e000282.
- Pasricha PJ. New duodenoscope designs: not what we had hoped for. Gastrointest Endosc 2022 Sep;96(3):567-568.
- Ofosu A, et al. Analysis of reported adverse events related to single-use duodenoscopes and duodenoscopes with detachable endcaps. Gastrointest Endosc 2022 Jul; 96(1):67-72.
- Forbes N, et al. Infection control in ERCP using a duodenoscope with a disposable cap (ICECAP): rationale for and design of a randomized controlled trial. BMC Gastroenterol 2020 Mar 12;20(1):64.
Sponsorship: This article’s research and writing were sponsored, in part, by AMBU, which received FDA clearance in 2023 for a sterile, single-use, flexible colonoscope. The author had complete and unfettered control over its preparation, design, content and recommendations. The company was unaware of, and did not edit, revise or otherwise change, this article’s content prior to publication.
Article by: Lawrence F Muscarella, PhD. Copyright (2023). LFM Healthcare Solutions, LLC. All rights reserved. Dr. Muscarella is the president and founder of LFM Healthcare Solutions, LLC, an independent quality improvement company. Click here for a list of his quality improvement healthcare services. E: Larry@LFM-HCS.com. Note: Some of this article’s content has been updated since its original publication date. Its most recent update was on April 8, 2024. [LFM-ver-3.5]