Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Colonoscopy

Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Colonoscopy

Effect of Water Exchange Plus Acetic Acid Staining on the Detection of Flat Polyps During Screening and Surveillance Colonoscopy: a Multi-centered, Randomized Controlled Study.

Our previous study (Am. J. Gastroenterol. 2017 04;112(4)) showed that water exchange (WE) colonoscopy was able to increase the detection of flat adenomas as well as overall ADR. We hypothesized that WE based whole-colon acetic acid（AA） staining might be useful to improve the detection of flat lesions compared with WE alone.

Water exchange colonoscopy was performed as described previously (Am. J. Gastroenterol. 2017 04;112(4)). Patients were randomly allocated to WE group or WE+AA group. In WE+AA group, water containing 1% of AA was used during insertion of colonoscopy instead of water alone. A bottle of 20ml pure AA was placed abutting the water pump, which make it possible to keep patients blinded to group allocation. Endoscopist using a high-definition wide-angle Olympus or Fujinum colonoscope performed all of the colonoscopies, with a withdrawal time of at least 6 min. The observation was initially performed without the assistance of cap or the use of magnification or electronic staining (NBI, BLI, LCI or AFI et al.). Scopolamine butylbromide or glucogon was not routinely administrated.

The water exchange colonoscopy is used during insertion procedure, in which the water contains 1% acetic acid, and the liquid is absorbed during the withdrawal process for observation.

The water exchange colonoscopy is used during insertion procedure, and the liquid is absorbed during the withdrawal process for observation.

Adenoma detection rate, defined as the proportion of subjects with at least one adenoma of any size, in each group.

Advanced adenoma detection rate. Advanced adenoma: any with 3 or more adenomas of any size, 1 or more large adenomas 1 cm, or 1 or more adenomas with villous architecture or highgrade dysplasia.

SSA/P detection rate, defined as the proportion of subjects with at least one sessile serrated adenoma/polyp (SSA/P) of any size, in each group.

Low-grade adenoma, adenoma with villous components, high-grade adenoma, noninvasive carcinoma, and invasive carcinoma in proximal colon

the rate of bleeding and perforation during colonoscopy procedure and abdominal pain, diarrhea, hematochezia and change of defecation habit Within one week.

Inclusion Criteria: Aged 40-70 Undergoing colonoscopy after standard bowel preparation Exclusion Criteria: Known familial polyposis Small amount of feces or semi-solid stool in last rectal effluent Inflammatory Bowel Disease Lactated or pregnant women Unable to provide informed content

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