Prospective RCT Of Water Exchange (WE) vs. WE Plus Cap-Assisted Colonoscopy

NCT ID: NCT03160859

Last Updated: 2023-12-12

Study Results

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

280 participants

Study Classification

INTERVENTIONAL

Study Start Date

2018-06-08

Study Completion Date

2022-10-28

Brief Summary

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This is a study to compare two different, but normally, used methods of colonoscopy in patients undergoing colonoscopy without sedation. There will be two arms in this study: WE (water exchange) control, and WE (water exchange) plus cap (placed at tip of the colonoscope). The patient will prepare himself/herself for the colonoscopy as per normal instructions and he/she will be given the information for the study at that time so that he/she can make a decision to participate in the study. The control method will use water instead of air during insertion of the colonoscope. The study method will use a cap that will fit onto the end of the colonoscope plus water during insertion of the colonoscope. This study will assess if the study method is less painful than the control method.

Detailed Description

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This will be a multi-VA site, unblinded investigators, prospective randomized control trial (RCT). Randomization (WE, WE + cap) will be based on computer generated random numbers placed inside opaque sealed envelopes. The envelope (in pre-arranged order set up by statistics consultant) will be opened to reveal the code when the colonoscopist is ready to insert the endoscope to begin the examination. This will be a comparison of two arms (WE, WE + cap) to see which one is less painful.

Patients who are willing to participate will sign an informed consent before starting the colonoscopy procedure. Separate parallel randomization will be set up at each site, stratified type of colonoscopy (screening, surveillance, diagnostic). All subjects will have scheduled unsedated colonoscopy as a result of lack of escort or personal preference for no sedation. Randomization will be set up by statistics consultant.

Control Method: One arm of the study will include unsedated colonoscopy with water exchange (WE) as the control method. Residual air in the colon will be removed and water will be infused to guide insertion through an airless lumen. Infused water will be removed by suction, along with residual fecal debris, predominantly during insertion.

Study method: The other arm will include unsedated colonoscopy with water exchange (WE) and the addition of a cap, fitted to the colonoscope per manufacturer instruction.

Conditions

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Unsedated Colonoscopy Water Exchange Colonoscopy Cap Colonoscopy Pain

Keywords

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unsedated colonoscopy water exchange colonoscopy cap colonoscopy pain

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

This will be a multi-VA site, prospective RCT to compare different methods with 2 arms to determine which is less painful: water alone or water plus cap. Randomization will be based on computer generated random numbers placed inside opaque sealed envelopes. The envelope will be opened to reveal the code when the colonoscopist is ready to insert the endoscope to begin the examination. Patients who are willing to participate will sign an informed consent before starting the colonoscopy procedure. Separate parallel randomization will be set up at each site. Control Method: Involves unsedated colonoscopy with water exchange. Residual air will be removed and water will be infused to guide insertion through an airless lumen. Infused water will be removed by suction, along with residual fecal debris, predominantly during insertion. Study method: Involves unsedated colonoscopy with water exchange and the addition of a commercially available accessory fitted onto the colonoscope.
Primary Study Purpose

SUPPORTIVE_CARE

Blinding Strategy

SINGLE

Participants

Study Groups

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Control Method

One arm of the study will include unsedated colonoscopy with water exchange (WE) as the control method. Residual air in the colon will be removed and water will be infused to guide insertion through an airless lumen. Infused water will be removed predominantly during insertion.

Group Type OTHER

Control

Intervention Type OTHER

Unsedated colonoscopy with water exchange (WE) where the residual air in the colon will be removed and water will be infused to guide insertion through an airless lumen. Infused water is removed predominantly during insertion.

Study Method

The other arm will include unsedated colonoscopy with water exchange (WE) and the addition of a simple commercially available accessory to the colonoscopy device: a cap (Disposable Distal Attachment, Olympus Medical Systems Corp., Tokyo, Japan) fitted to the colonoscope per manufacturer instruction. Residual air in the colon will be removed and water will be infused to guide insertion through an airless lumen. Infused water will be removed predominantly during insertion.

Group Type OTHER

Study method

Intervention Type DEVICE

Unsedated colonoscopy with water exchange (WE + cap) and the addition of a cap fitted to the colonoscope.

Interventions

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Control

Unsedated colonoscopy with water exchange (WE) where the residual air in the colon will be removed and water will be infused to guide insertion through an airless lumen. Infused water is removed predominantly during insertion.

Intervention Type OTHER

Study method

Unsedated colonoscopy with water exchange (WE + cap) and the addition of a cap fitted to the colonoscope.

Intervention Type DEVICE

Other Intervention Names

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Water exchange method Water exchange method plus cap

Eligibility Criteria

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Inclusion Criteria

* Informed/educated (about pros and cons of the unsedated option) Veterans undergoing:

* diagnostic
* surveillance (follow up of polyps)
* screening (first-time) colonoscopy at participating sites
* choosing scheduled unsedated colonoscopy for any reason (lack of escort, personal preference)

Exclusion Criteria

* decline to be randomized
* unable to give consent or respond to questionnaires
* history of colon surgery
* active inflammatory bowel disease
* lower gastrointestinal bleeding (except for occult blood or FIT positive in the context of colon cancer screening)
* therapeutic colonoscopy (e.g., hemostasis, removal of large polyp)
* proctosigmoidoscopy
* bidirectional endoscopy
* inadequate consumption of bowel preparation
* known history of severe diverticulosis or diverticulitis
* history of abdominal surgery previously requiring sedation for colonoscopy
* current narcotic/anxiolytic medication use
* prior unsuccessful experience with unsedated colonoscopy
* emergent colonoscopy
* evidence of colonic obstruction based on pre-colonoscopy clinical evaluation
* current participation in other studies
* medical condition that could increase the risk associated with colonoscopy

* active cardiac
* or pulmonary disease
* or other serious disease
* medical condition that would preclude a benefit from colonoscopic screening

* cancer
* or any terminal illness
* prosthetic heart valve
* anticoagulant therapy
* nonmedical problems

* psychiatric disorders
* excessive use of alcohol
* need for special precautions in performing colonoscopy

* antibiotic prophylaxis
* request of on demand sedation
Minimum Eligible Age

50 Years

Maximum Eligible Age

80 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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VA Northern California Health Care System

FED

Sponsor Role collaborator

VA Palo Alto Health Care System

FED

Sponsor Role collaborator

VA Office of Research and Development

FED

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Felix W. Leung, MD

Role: PRINCIPAL_INVESTIGATOR

VA Greater Los Angeles Healthcare System, Sepulveda, CA

Locations

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VA Palo Alto Health Care System, Palo Alto, CA

Palo Alto, California, United States

Site Status

VA Northern California Health Care System, Mather, CA

Sacramento, California, United States

Site Status

VA Greater Los Angeles Healthcare System, Sepulveda, CA

Sepulveda, California, United States

Site Status

Countries

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United States

References

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Wolff WI, Shinya H. Polypectomy via the fiberoptic colonoscope. Removal of neoplasms beyond reach of the sigmoidoscope. N Engl J Med. 1973 Feb 15;288(7):329-32. doi: 10.1056/NEJM197302152880701. No abstract available.

Reference Type BACKGROUND
PMID: 4682941 (View on PubMed)

Leung FW. The case of unsedated screening colonoscopy in the United States. Gastrointest Endosc. 2009 Jun;69(7):1354-6. doi: 10.1016/j.gie.2008.12.234. Epub 2009 Feb 27. No abstract available.

Reference Type BACKGROUND
PMID: 19249764 (View on PubMed)

Leung FW, Aljebreen AM, Brocchi E, Chang EB, Liao WC, Mizukami T, Schapiro M, Triantafyllou K. Sedation-risk-free colonoscopy for minimizing the burden of colorectal cancer screening. World J Gastrointest Endosc. 2010 Mar 16;2(3):81-9. doi: 10.4253/wjge.v2.i3.81.

Reference Type BACKGROUND
PMID: 21160707 (View on PubMed)

Leung FW. Is there a place for sedationless colonoscopy? J Interv Gastroenterol. 2011 Jan;1(1):19-22. doi: 10.4161/jig.1.1.14592.

Reference Type BACKGROUND
PMID: 21686108 (View on PubMed)

Cataldo PA. Colonoscopy without sedation. Dis Colon Rectum. 1996 Mar;39(3):257-61. doi: 10.1007/BF02049463.

Reference Type BACKGROUND
PMID: 8603544 (View on PubMed)

Hoffman MS, Butler TW, Shaver T. Colonoscopy without sedation. J Clin Gastroenterol. 1998 Jun;26(4):279-82. doi: 10.1097/00004836-199806000-00013.

Reference Type BACKGROUND
PMID: 9649011 (View on PubMed)

Rex DK, Imperiale TF, Portish V. Patients willing to try colonoscopy without sedation: associated clinical factors and results of a randomized controlled trial. Gastrointest Endosc. 1999 May;49(5):554-9. doi: 10.1016/s0016-5107(99)70381-0.

Reference Type BACKGROUND
PMID: 10228251 (View on PubMed)

Subramanian S, Liangpunsakul S, Rex DK. Preprocedure patient values regarding sedation for colonoscopy. J Clin Gastroenterol. 2005 Jul;39(6):516-9. doi: 10.1097/01.mcg.0000165667.79530.44.

Reference Type BACKGROUND
PMID: 15942439 (View on PubMed)

Early DS, Saifuddin T, Johnson JC, King PD, Marshall JB. Patient attitudes toward undergoing colonoscopy without sedation. Am J Gastroenterol. 1999 Jul;94(7):1862-5. doi: 10.1111/j.1572-0241.1999.01219.x.

Reference Type BACKGROUND
PMID: 10406249 (View on PubMed)

Leung FW. Patients' perspective - written testimonials from physician-patients and oral accounts presented by patients in person. J Interv Gastroenterol. 2011 Jan;1(1):45-46. doi: 10.4161/jig.1.1.14605. No abstract available.

Reference Type BACKGROUND
PMID: 21686115 (View on PubMed)

Jonas DE, Russell LB, Sandler RS, Chou J, Pignone M. Patient time requirements for screening colonoscopy. Am J Gastroenterol. 2007 Nov;102(11):2401-10. doi: 10.1111/j.1572-0241.2007.01387.x. Epub 2007 Jun 29.

Reference Type BACKGROUND
PMID: 17608779 (View on PubMed)

Leung FW. Unsedated colonoscopy introduced to ensure access is acceptable to a subgroup of veterans. Dig Dis Sci. 2008 Oct;53(10):2719-22. doi: 10.1007/s10620-007-0192-8. Epub 2008 Feb 15.

Reference Type BACKGROUND
PMID: 18274901 (View on PubMed)

Felix W. Leung, Hartley Cohen, Stanley K. Dea, Dennis M. Jensen, Thomas O. Kovacs, Gordon V. Ohning, Joseph R. Pisegna, Alireza Sedarat, Alan Sheinbaum, Timothy C. Simmons, Rebecca Slomovic, Brennan M. Spiegel, Mitchell J. Spirt, James Sul and Rabindra R. Watson. Scheduled unsedated colonoscopy - a novel tool for managing no shows due to lack of escorts required for conscious sedation. Gastrointestinal Endoscopy, 2014-05-01, Volume 79, Issue 5, Pages AB178-AB179

Reference Type BACKGROUND

Terruzzi V, Meucci G, Radaelli F, Terreni N, Minoli G. Routine versus "on demand" sedation and analgesia for colonoscopy: a prospective randomized controlled trial. Gastrointest Endosc. 2001 Aug;54(2):169-74. doi: 10.1067/mge.2001.113923.

Reference Type BACKGROUND
PMID: 11474385 (View on PubMed)

Leung FW, Harker JO, Jackson G, Okamoto KE, Behbahani OM, Jamgotchian NJ, Aharonian HS, Guth PH, Mann SK, Leung JW. A proof-of-principle, prospective, randomized, controlled trial demonstrating improved outcomes in scheduled unsedated colonoscopy by the water method. Gastrointest Endosc. 2010 Oct;72(4):693-700. doi: 10.1016/j.gie.2010.05.020. Epub 2010 Jul 8.

Reference Type BACKGROUND
PMID: 20619405 (View on PubMed)

Leung JW, Mann SK, Siao-Salera R, Canete W, Leung FW. The established and time-tested water exchange method in scheduled unsedated colonoscopy significantly enhanced patient-centered outcomes without prolonging procedural times - A RCT. J Interv Gastroenterol. 2013;3(1):7-11.

Reference Type BACKGROUND

Hsieh YH, Koo M, Leung FW. A patient-blinded randomized, controlled trial comparing air insufflation, water immersion, and water exchange during minimally sedated colonoscopy. Am J Gastroenterol. 2014 Sep;109(9):1390-400. doi: 10.1038/ajg.2014.126. Epub 2014 Jun 3.

Reference Type BACKGROUND
PMID: 24890443 (View on PubMed)

Cadoni S, Gallittu P, Sanna S, Fanari V, Porcedda ML, Erriu M, Leung FW. A two-center randomized controlled trial of water-aided colonoscopy versus air insufflation colonoscopy. Endoscopy. 2014 Mar;46(3):212-8. doi: 10.1055/s-0033-1353604. Epub 2013 Nov 11.

Reference Type BACKGROUND
PMID: 24218307 (View on PubMed)

Cadoni S, Sanna S, Gallittu P, Argiolas M, Fanari V, Porcedda ML, Erriu M, Leung FW. A randomized, controlled trial comparing real-time insertion pain during colonoscopy confirmed water exchange to be superior to water immersion in enhancing patient comfort. Gastrointest Endosc. 2015 Mar;81(3):557-66. doi: 10.1016/j.gie.2014.07.029. Epub 2014 Sep 26.

Reference Type BACKGROUND
PMID: 25262100 (View on PubMed)

Cadoni S, Falt P, Gallittu P, Liggi M, Mura D, Smajstrla V, Erriu M, Leung FW. Water Exchange Is the Least Painful Colonoscope Insertion Technique and Increases Completion of Unsedated Colonoscopy. Clin Gastroenterol Hepatol. 2015 Nov;13(11):1972-80.e1-3. doi: 10.1016/j.cgh.2015.04.178. Epub 2015 May 5.

Reference Type BACKGROUND
PMID: 25956838 (View on PubMed)

Kim HG. Painless Colonoscopy: Available Techniques and Instruments. Clin Endosc. 2016 Sep;49(5):444-448. doi: 10.5946/ce.2016.132. Epub 2016 Sep 30.

Reference Type BACKGROUND
PMID: 27744665 (View on PubMed)

Morgan J, Thomas K, Lee-Robichaud H, Nelson RL, Braungart S. Transparent cap colonoscopy versus standard colonoscopy to improve caecal intubation. Cochrane Database Syst Rev. 2012 Dec 12;12(12):CD008211. doi: 10.1002/14651858.CD008211.pub3.

Reference Type BACKGROUND
PMID: 23235654 (View on PubMed)

Holme O, Bretthauer M, de Lange T, Seip B, Huppertz-Hauss G, Hoie O, Sandvei P, Ystrom CM, Hoff G. Risk stratification to predict pain during unsedated colonoscopy: results of a multicenter cohort study. Endoscopy. 2013 Sep;45(9):691-6. doi: 10.1055/s-0033-1344239. Epub 2013 Jul 24.

Reference Type BACKGROUND
PMID: 23884794 (View on PubMed)

Wang L, Jia H, Luo H, Kang X, Zhang L, Wang X, Yao S, Tao Q, Pan Y, Guo X. A novel intubation discomfort score to predict painful unsedated colonoscopy. Medicine (Baltimore). 2021 Mar 12;100(10):e24907. doi: 10.1097/MD.0000000000024907.

Reference Type BACKGROUND
PMID: 33725848 (View on PubMed)

Anderson JC, Gonzalez JD, Messina CR, Pollack BJ. Factors that predict incomplete colonoscopy: thinner is not always better. Am J Gastroenterol. 2000 Oct;95(10):2784-7. doi: 10.1111/j.1572-0241.2000.03186.x.

Reference Type BACKGROUND
PMID: 11051348 (View on PubMed)

Leung FW, Cheung R, Friedland S, Jacob N, Leung JW, Pan JY, Quan SY, Sul J, Yen AW, Jamgotchian N, Chen Y, Dixit V, Shaikh A, Elashoff D, Saha A, Wilhalme H. Prospective randomized controlled trial of water exchange plus cap versus water exchange colonoscopy in unsedated veterans. Gastrointest Endosc. 2025 Feb;101(2):402-413.e2. doi: 10.1016/j.gie.2024.07.010. Epub 2024 Jul 23.

Reference Type DERIVED
PMID: 39053653 (View on PubMed)

Provided Documents

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Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

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GAST-015-16S

Identifier Type: -

Identifier Source: org_study_id

NCT03543124

Identifier Type: -

Identifier Source: nct_alias