CHICAGO—A third-generation over-the-scope intraprocedural cleansing system could serve as a solution for inadequate bowel preparation, which remains a common obstacle to optimal colonoscopy. Use of the system nearly halved the rate of inadequate bowel prep in a study presented at Digestive Disease Week 2023.
“We evaluated the big-picture, real-world effect of the implementation of an intraprocedural cleansing system into our practice and found that it significantly reduced the rate of inadequate bowel prep. While intraprocedural cleansing does not replace preprocedural bowel prep strategies, it does enhance bowel prep,” said investigator Tessa Herman, MD, a second-year internal medicine resident at the University of Minnesota, Minneapolis VA Medical Center.
The single-use oversleeve-based system (Pure-Vu EVS, Motus GI) uses high-intensity water and air to cleanse the colon while not inhibiting the use of the working channel (Figure). In prior studies, use of this device resulted in adequate bowel prep rates as high as 98% and cecal intubation rates of 98% (J Clin Gastroenterol 2019;53[7]:530-534), Dr. Herman said.
She, along with co-investigators including Brian Hanson, MD, the gastroenterology section chief and director of endoscopy at the Minneapolis VA, conducted a retrospective study to determine whether the use of this cleansing system reduced the rate of inadequate bowel prep in colonoscopies performed at the hospital over a 12-month period (abstract 53). The investigators compared the adequacy of bowel preparation at the time of colonoscopy in the six months before and after implementation of the system. Inadequate prep was defined as a Boston Bowel Preparation Scale score less than 6 or a bowel preparation described as poor or inadequate per the Aronchick scale.
The study was based on 2,367 colonoscopies, including 1,198 pre-implementation cases and 1,169 post-implementation cases, with the cleansing system used in 46 cases.
Explaining the way the system’s use evolved over time, Dr. Herman said, “At first we used it proactively in patients we predicted would have an inadequate prep, such as based on past history. Now we primarily use the cleansing system during the colonoscopy as ‘rescue’ after endoscopic confirmation of poor prep. It’s an evolution, and we’re still working out the kinks of when to use it,” she said.
Half the Rate of Inadequate Prep
Use of the intraprocedural cleansing system essentially halved the rate of inadequate bowel prep, the investigators reported. During the six-month pre-implementation period, 111 cases involved inadequate bowel prep, resulting in a rate of 9.3%. Post-implementation, only 69 cases began with inadequate preps, for a far lower rate of 5.9%, which Dr. Herman said was “a statistically significantly (P=0.002) and clinically meaningful difference that far exceeds the minimum standards.”
Looking deeper at the 46 cases in which the device was used, 36 were deemed technically successful, for an overall procedural success rate of 78.3%. For the 10 cases in which the device did not produce a good outcome, two were because of patient intolerance of sedation, seven were related to anatomic obstacles (i.e., device-free scope could not pass), and one was the result of the device being unable to clear solid stool, she said.
Can Help Prevent Lost to Follow-up
“While many patients could benefit from the use of this intraprocedural cleansing system, I think there are a few patient populations for whom it may be particularly helpful,” Dr. Herman said. “One is the population of patients who, despite all efforts, are unable to get an adequate prep. The other is the population at risk of [being] lost to follow-up.”
In a separate study from the Minneapolis VA and presented at Digestive Disease Week 2023, 41% of patients with inadequate bowel prep failed to undergo repeat colonoscopy within one year, and 26% never followed through at all (abstract Sa1010). “It’s critical to achieve optimal visualization at the first colonoscopy,” she said.
Optimizing Use of the System
“This is a really interesting study,” said Audrey H. Calderwood, MD, MS, the director of the Comprehensive Gastroenterology Center at Dartmouth Hitchcock Medical Center, in Lebanon, N.H. “It supports that a good percentage of inadequate bowel preparations can be salvaged with use of the Pure-Vu EVS System. I would be interested to learn more about predictors of technical success/failure, how best to implement in practice, and the implications for extra time needed per case, unit efficiency and downstream cost.”
Responding to these points, Dr. Hansen told Gastroenterology & Endoscopy News that “the best way to ensure proper use and technical success is to pass the endoscope through the sigmoid colon and ideally to the cecum to document the prep. If the device-free scope can be passed and the procedure tolerated, there is reasonable certainty the colonoscopy can be completed successfully with PureVu.” He shared some of the team’s intraprocedural tips for success (Table).
| Table. Tips to Optimize Use of Intraprocedural Cleansing System |
| Add 2.5 mL of simethicone per 1 L of irrigation water to reduce air bubbles generated by lavage |
| Add a solidifier to the suction canister to help with waste management |
| Add diphenhydramine for patients under moderate sedation who may require slightly more sedation than in standard colonoscopies |
| Remove the plastic oversleeve to improve scope maneuverability and loop reduction without affecting function or procedural safety |
To optimize outcomes early on, the team recommends that initial cases are patients who have achieved poor, but not very poor, bowel preparation and can tolerate sedation well. In addition, they advise factoring in extra procedure time when starting out to allow for a learning curve and over time assembling a team of endoscopists, nurses and technicians who become skilled in the setup and use of the device.
Regarding cost of the system, he said considerations include “the cost of device, endoscopy time, and case delays if intraprocedural cleansing is time-consuming,” but these need to be weighed against the “costs of inadequate prep, including delays in diagnosis, repeat procedure costs, patient and caregiver time, and the potential for [patients being] lost to follow up. ”
—Caroline Helwick and Sarah Tilyou
Dr. Calderwood reported a financial relationship with Dark Canyon Laboratories. Dr. Hanson reported a financial relationship with Motus GI, but the study was investigator-driven and not funded by the manufacturer. Dr. Herman reported no relevant financial disclosures.
This article is from the July 2023 print issue.