Randomized-Controlled Trial Comparing Adenoma Detection Rate Using Water Exchange Versus Air Insufflation Colonoscopy In A Us Community-Based Setting

Introduction: Efforts are underway to improve adenoma detection rate during screening colonoscopies, especially in the right colon. Water exchange colonoscopy has demonstrated promising results, purportedly by better cleansing of the colon, and has also resulted in less patient discomfort. Majority of these studies were conducted in a predominantly male and Caucasian VA population. We report the first community-based RCT in the USA that includes female and minority populations, comparing water exchange with air insufflation method in assessing adenoma detection rate. Methods: A prospective sample of 178 patients above 50 years of age presenting for screening and surveillance colonoscopies at a community-based endoscopy center, with no personal or family history of colon cancer, familial polyposis syndromes, inflammatory bowel disease, or prior history of colonic surgery, who consented for the study were blinded and randomized to either water exchange (n=88) or air insufflation colonoscopy (n=88). Four endoscopists participated in the trial. All patients received adequate sedation prior to scope insertion, followed by sequential doses as needed. All patient received a split bowel prep. Prep quality was assessed by the Boston Bowel Prep Score. Post-procedure pain and recovery time were assessed by a nurse blinded to the colonoscopy technique. All colon polyps were assessed by expert GI pathologists. Sessile serrated lesions were reported when found. Advanced adenomas were defined as villous or tubulovillous in histology, or size > 1 cm. Adenomas found proximal to splenic flexure were reported as proximal adenomas. Results: Of 178 patients, 3 were excluded from final analysis, 1 in the air group diagnosed with FAP, and 2 in the water group requiring switch to pediatric colonoscopes due to tortuous sigmoids. There were no statistically significant differences between the 2 groups in terms of sex, race (Caucasian, Black, Hispanic, Asian), age, BMI, alcohol and tobacco use, bowel prep quality, sedation requirement, abdominal pressure application, patient position change, endoscope stiffner use, or scope length at cecum. The cecum was intubated in all patients. Conclusion: Water exchange colonoscopy is a viable technique in a busy community-based endoscopy center. It demonstrated a trend towards higher polyp, adenoma, sessile serrated lesion and advanced adenoma detections. It resulted in significantly lower post procedure pain and recovery time, without significantly increasing procedure time.Table 1: Baseline patient characteristicsTable 2: Polyp detection rates, procedure and recovery times, and post procedure pain