Elsevier

Gastrointestinal Endoscopy

Volume 88, Issue 4, October 2018, Pages 589-597.e11
Gastrointestinal Endoscopy

Systematic review and meta-analysis
Water exchange colonoscopy increases adenoma detection rate: a systematic review with network meta-analysis of randomized controlled studies

https://doi.org/10.1016/j.gie.2018.06.028Get rights and content

Background and Aims

Water-aided colonoscopy techniques, such as water immersion (WI) and water exchange (WE), have shown different results regarding adenoma detection rate (ADR). We determined the impact of WI and WE on ADR and other procedural outcomes versus gas (air, AI; CO2) insufflation colonoscopy.

Methods

A systematic search of multiple databases for randomized controlled trials comparing WI and/or WE with AI and/or CO2 and reporting ADR was conducted. A network meta-analysis with mixed comparisons was performed. Primary outcome was ADR (overall, in the right side of the colon and by colonoscopy indication).

Results

Seventeen randomized controlled trials (10,350 patients) were included. WE showed a significantly higher overall ADR versus WI (odds ratio [OR], 1.31; 95% credible interval [CrI], 1.12-1.55) versus AI (OR, 1.40; CrI, 1.22-1.62) versus CO2 (OR, 1.48; 95% CrI, 1.15-1.86). WE achieved the highest ADR also in the right side of the colon and in colorectal cancer screening cases (both significant vs AI and WI) as well as in patients taking a split-dose preparation (significant vs all the other techniques). The Boston Bowel Preparation Scale cleanliness score (vs AI and WI) was significantly higher for WE. Both WI and WE showed increased proportion of unsedated examinations and decreased real-time insertion pain, with WE being the least-painful insertion technique. Withdrawal time was comparable across techniques, but WE showed the longest insertion time (3-5 additional minutes).

Conclusions

WE significantly increases overall ADR, ADR in screening cases, and in the right side of the colon; it also improves colon cleanliness but requires a longer insertion time.

Abbreviations

ADR
adenoma detection rate
AI
air
BBPS
Boston Bowel Preparation Scale
CI
confidence interval
CrI
credible interval
CRC
colorectal cancer
MD
mean difference
OR
odds ratio
RCT
randomized controlled trial
WAC
water-aided colonoscopy
WE
water exchange
WI
water immersion

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DISCLOSURE: D. Rex, consultant for and the research support from Boston Scientific and Olympus. All authors disclosed no financial relationships relevant to this publication.

See CME section; p. 745.

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