Water Immersion Colonoscopy

Water Immersion Colonoscopy

Gastrocure in West Orange, NJ performs comprehensive cancer screenings for colon cancer and Barrett’s esophagus. He performs quality colonoscopy using high definition optical colonoscopy, narrow band imaging to identify early flat lesions in the right colon which could be missed during routine colonoscopy. In difficult cases we use a Water Immersion Colonoscopy technique to complete procedures which decrease pain and sedation amount for patients.

The Water Immersion Technique for Colonoscopy Insertion
Shai Friedland, MD

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G&H Could you discuss the use of water immersion for colonoscopy insertion?

SF Water immersion is a technique that has been used for over 30 years. The first time I encountered it was approximately 10 years ago with Dr. Harvey Young, one of our expert endoscopists at Stanford University, who was using it in a patient with a tortuous sigmoid colon. Over the years, we have used water immersion sporadically and have noted anecdotally that it helps reduce pain and occasionally makes difficult colonoscopies somewhat easier by straightening out the colon and reducing angulations. Several studies have been conducted over the years in Japan, Europe, and the United States describing the technique and have found that it appears to decrease pain during colonoscopy.
The basic concept with water immersion is that water, instead of air, is used to distend the colon enough during insertion to visualize the way forward. Air pockets that are encountered are also suctioned. Keeping the lumen minimally distended with water appears to reduce angulations in the colon and facilitate advancement with less looping of the instrument.
G&H Is there a demand from patients for an alternative to air insufflation for colonoscopy? How has the water immersion technique been received by patients?

SF When talking to patients prior to colonoscopy and asking them about their concerns for the procedure, the number one concern (other than the bowel preparation) is pain during the procedure. Different patients have different attitudes regarding sedation—whether they want to be completely unconscious and not remember anything or whether they would prefer to stay more aware and watch—but all patients want to avoid pain. We explain to them that the water immersion method makes colonoscopy less painful and that they will receive as much pain medicine as they need during the procedure, but that they are likely to need much less medicine with water immersion. Patients are usually quite receptive toward any technique that minimizes pain during the procedure. I use water immersion routinely on all patients except when the bowel preparation is poor and good visualization is impossible with water.
G&H You recently published a study evaluating water immersion versus standard colonoscopy insertion. Could you describe your study design and findings?

SF Over 200 men at the Veteran Affairs Palo Alto Healthcare System were randomized to undergo minimal sedation colonoscopy with either the water immersion method or standard air insufflation during insertion of the colonoscope. All of the patients in the study were administered 2 mg of midazolam before the procedure. During the colonoscopy, their pain level was recorded periodically and if they had a pain level higher than 4 on a scale out of 10, it was considered a failure of minimal sedation and the patients received fentanyl and any additional midazolam to permit completion of the procedure comfortably. Our goal was to determine whether the patients in the water group could tolerate this minimal sedation colonoscopy better than the air insufflation group. We found this to be true, regardless of who performed the colonoscopy—experienced attendings or fellows in training. In the water immersion group, patients experienced less pain and needed less medicine.
G&H What did you conclude from your study?

SF We concluded that the water immersion technique is less painful and that it facilitates the performance of colonoscopy with minimal sedation. We also demonstrated that it does not compromise any other aspects of colonoscopy; for example, the procedure does not take longer with the water method. Colonoscopies with water immersion actually tended to be a little shorter, both during the insertion and during the withdrawal. We proposed that the withdrawal was a little shorter in our patients because additional cleaning occurred from the water during insertion, so even though it was necessary to suction a good deal of water during withdrawal, there was less need for lavage of dirty areas. It is also important to note that water immersion did not compromise the adenoma detection rate.
G&H What are the limitations of the water immersion technique for colonoscope insertion?

SF Water immersion is very difficult if the colon is not prepared well for the examination. Residue can be suctioned while infusing more water, which helps to clean the colon, but if there is too much residue, it is very difficult to see clearly enough to insert the colonoscope properly. This potential challenge is a significant drawback of this method. However, as we all continue to work to improve adenoma detection during colonoscopy, I suspect that there will be increasing emphasis on improving bowel preparation to maximize adenoma detection, and better-prepped patients will be good candidates for water immersion.
G&H How difficult is the water immersion method to learn and use?

SF During the study, it was interesting to see, particularly with the fellows in training, that there was a fair amount of resistance toward learning a new technique. At first, water immersion is awkward because the endoscopist is used to doing things the way that they have always done them, and looking at the colon underwater is different. With an underwater view, the endoscopist can see up close but has trouble seeing far away, so it takes some patience merely to avoid the temptation to fill the lumen up with air. It is also important to learn to recognize diverticula, the appendix, and blind ends in postsurgical patients to avoid advancing where there is no lumen (thankfully, I have never seen this actually happen).
In addition, when using water immersion, it actually feels as if the procedure is going slowly because advancement is slow and steady. It often seems faster to just fill the colon up with air to achieve a wide-open view. However, colonoscopy actually takes longer with air insufflation because the procedure often ends up being more difficult and more time is spent reducing or maneuvering through tighter turns. During our randomized study, we timed the procedures and found that the cecum was actually reached faster with water immersion. We tell our fellows to be patient and to avoid air insufflation, as water immersion will actually save them time in the long run and make the procedure easier. After becoming more comfortable with the technique, it is quite easy to use.
To help gastroenterologists learn more about the water method and how to incorporate it into their practice, we are making a teaching video that demonstrates all of the technical aspects of how to use it, what to look for, and the different variations in technique that have been described. Hopefully, this video will help physicians become more comfortable with the technique and encourage them to try it in a safe manner, as we believe that water immersion is a method that every experienced endoscopist can learn on their own.
G&H Are there any upcoming studies evaluating water immersion in colonoscopy that you are anticipating?

SF Dr. Felix Leung will be publishing a randomized study comparing the water method with air in unsedated colonoscopy in Gastrointestinal Endoscopy later this year. Preliminary results of the study suggest that unsedated colonoscopy is more successful in the water group.
One of the limitations of our study was that it did not include women, as it consisted of only men at a Veterans Affairs hospital. This is an excellent area for future research on the water immersion method, particularly as colonoscopy is known to be more difficult in women.

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