Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations

Sergio Cadoni, Sauid Ishaq, Cesare Hassan, P. emysl Falt, Lorenzo Fuccio, Keith Siau, Joseph W. Leung, John Anderson, Kenneth F. Binmoeller, Franco Radaelli, Matt D. Rutter, Shinya Sugimoto, Humayun Muhammad, Pradeep Bhandari, Peter V. Draganov, Piet de Groen, Andrew Y. Wang, Andrew W. Yen, Chris Hamerski, Henrik ThorlaciusHelmut Neumann, Francisco Ramirez, Chris J. J. Mulder, Eduardo Albéniz, Arnaldo Amato, Makoto Arai, Adrian Bak, Maximilien Barret, Putut Bayupurnama, Ramsey Cheung, Hey-Long Ching, Hartley Cohen, Sunil Dolwani, Shai Friedland, Hideaki Harada, Yu-Hsi Hsieh, Bu Hayee, Toshio Kuwai, Vicente Lorenzo-Zúñiga, Mauro Liggi, Takeshi Mizukami, Donatella Mura, David Nylander, Snorri Olafsson, Silvia Paggi, Yanglin Pan, Adolfo Parra-Blanco, Rupert Ransford, Joaquìn Rodriguez-Sanchez, Hakan Senturk, Noriko Suzuki, Chih-Wei Tseng, Hugo Uchima, Noriya Uedo, Felix W. Leung

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33 Citations (Scopus)


Background and Aims: Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR. Methods: Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements. Results: In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11). Conclusions: The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.
Original languageEnglish
Pages (from-to)1411-1420.e18
JournalGastrointestinal Endoscopy
Issue number6
Early online date2021
Publication statusPublished - Jun 2021

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