Water Exchange With Narrow Band Imaging on Adenoma Detection

Design: Prospective single-blinded randomized controlled trial. Patients were randomly assigned to control group or study group through a computer-based randomization list by a technician. See also inclusion and exclusion criteria. Colonoscopy was performed using high-definition colonoscope (GIF-HQ290I) after bowel preparation. Experienced endoscopists (each with over 3000 colonoscopies performed) and fellows (performed more than 600 colonoscopies) performed all procedures. During the insertion phase, air pump was turned off to avoid inadvertent insufflations. Water exchange with infusion pump was used to open the lumen and simultaneous suction of infused water to allow passage of the scope in clear water. Suction of water can maximize cleanliness and minimize distension. Air pockets at any location of the lumen were always aspirated. In a collapsed colon, water turbulence formation at the tip of the scope facilitates residual feces removal, salvage cleansing also be provided during insertion. Simethicone was used to remove bubbles over the mucosa. Cecal intubation was defined as the passage of the scope tip beyond the ileocecal valve with visualization of the cecal appendix. After cecal intubation, as much residual water as possible was aspirated before beginning the withdrawal phase. The same endoscopist uses the same assigned method to perform tandem or back-to-back colonoscopy on all patients. After the first colonoscopic examination with the colonoscope removed from the anus, using the same entry method for insertion and the same assigned method for the second colon examination. In all arms, withdrawal lasted at least 9 minutes and was done using air insufflation to obtain adequate distension. A stopwatch was used to time the procedures, and time for polypectomy was not included. Colon cleanliness was assessed using the Boston Bowel Preparation Scale (BBPS) and bubble scores. Cardiopulmonary function was monitored throughout, and adverse outcomes were recorded. Study end points The primary outcome was to compare the ADR of the 290-NBI with the HD-WL. Secondary outcomes included Right and left colon Adenoma Detection Rate. Right and left colon \<10 mm Adenoma Detection Rate. Mean adenomas resected per procedure. Cecal intubation rate. Cecal intubation time. Total withdrawal time. Amount of water used during the procedure. Adenoma and polyp miss rate between the two group.