Clinical Trial: Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy: a Single-centered, Randomized Controlled Study

Brief Summary: Patients with colorectal adenomas are suggested to receive polypectomy. A substantial number of adenomas may be missed in patients with polyps found by previous colonoscopy. And water exchange (WE) method may increase the detection of missed adenoma compared with traditional air insufflation (AI) colonoscopy. The investigators aim to investigate whether water exchange colonoscopy method, compared with air insufflation method, can improve the detection of missed adenomas in patients undergoing selective polypectomy.

Detailed Summary:

For WE method, the air pump was turned off for the full duration of insertion to avoid inadvertent air insufflations and colon elongation. Residual air in the lumen was suctioned to minimize angulations at flexures. Water at 37°C was infused with a pump (Olympus) through the biopsy channel to confirm correct tip orientation for scope advancement. The infused water was removed predominantly by suction when the colonoscope was smoothly advanced during the insertion phase, and turbid luminal water due to residual feces was exchanged by clean water until the lumen was clearly visualized. Occasionally, if it was difficult to determine whether the colonoscope tip was in the cecum, air was allowed to be insufflated for observation. If the position of the scope tip was confirmed to be not in the cecum, insufflated air would be removed by suction and the WE method would be continuously used until successful intubation.

For the AI method, water was not used, and air was insufflated during insertion.

Air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal for both methods. Polyps will be removed by forceps biopsy (polyps size <3mm), cold snare technique (3-6mm) or endoscopic mucosal resection (size≥6mm).

Current Primary Outcome: Adenoma miss rate [ Time Frame: 12 months ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• adenoma-level miss rate [ Time Frame: 12 months ]
  Adenoma-level miss rate was calculated as the number of additional adenomas detected in polypectomy procedure divided by the total number of adenomas in each group.
• Advanced adenoma miss rate/Miss advanced adenoma per colonoscopy [ Time Frame: 12 months ]
  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.
• Adenoma per positive patient (APP) [ Time Frame: 12 months ]
  The mean number of adenoma per positive patient
• Quality of Bowel Preparation [ Time Frame: 12 months ]
  The Boston Bowel Preparation Scale (BBPS): cleanliness of each part of the colon: 0=unprepared colon segment with mucosa not seen because of solid stool that cannot be cleared; 1=portion of mucosa of the colon segment seen, but other areas of the colon segment not well seen because of staining, residual stool, and/or opaque liquid; 2=minor amount of residual staining, small fragments of stool and/or opaque liquid, but mucosa of colon segment seen well; 3=entire mucosa of colon segment seen well with no residual staining, small fragments of stool, or opaque liquid.
• Complication rate [ Time Frame: 12 months ]
  Bleeding, perforation and others
• Pain Scores on the Visual Analog Scale compared with previous colonoscopy [ Time Frame: 12 months ]
  0 = no pain, to 10 = most severe pain

Original Secondary Outcome: Same as current

Information By: Fourth Military Medical University

Dates:
Date Received: August 19, 2016
Date Started: August 2016
Date Completion: August 2017
Last Updated: August 25, 2016
Last Verified: August 2016