The water method significantly enhances detection of diminutive lesions (adenoma and hyperplastic polyp combined) in the proximal colon in screening colonoscopy - data derived from two RCT in US veterans.

PURPOSE: Emerging data indicate a colonoscopist-controlled method is needed to avoid missing proximal colon pre-malignant lesions. Screening colonoscopy does not prevent all proximal colon cancers. Even diminutive lesions in the proximal colon harbor dysplasia. In addition to adenomas (presumptive cancer precursors), recent proposals to reevaluate proximal colon hyperplastic polyps as serrated polyps which could be pre-malignant or harbingers of interval neoplasia dramatize the importance of attending to these lesions. The finding that the water method increased yield of proximal diminutive adenomas prompted assessment of the hypothesis that the water method increases yield of all proximal diminutive lesions (adenoma and hyperplastic polyp) in screening cases. METHODS: Two RCT assessed the water method with primary outcome of completion of unsedated colonoscopy when the option of scheduled, unsedated or sedation on demand was used. Diminutive (<10 mm) lesions proximal to the splenic flexure were tracked. RESULTS: In screening cases, 31% and 6% of the water and air group had at least one proximal diminutive lesion (p=0.0012). Regression analysis revealed withdrawal time, method and volume of water used were significant predictors of proximal diminutive lesions. Effect of the water method on detection of proximal diminutive lesions was independent of age, body mass index, endoscopist, sedation, cecal intubation rate, bowel cleanliness score on withdrawal and total procedure time. LIMITATION: Male subject predominance, analysis of secondary outcomes of pooled RCT data. CONCLUSION: The hypothesis that the water method effectively enhances proximal diminutive lesion detection in screening colonoscopy in diverse clinical settings should be tested.

A proof-of-principle, prospective, randomized, controlled trial demonstrating improved outcomes in scheduled unsedated colonoscopy by the water method.

BACKGROUND: An observational study in veterans showed that a novel water method (water infusion in lieu of air insufflation) enhanced cecal intubation and willingness to undergo a repeat scheduled unsedated colonoscopy. OBJECTIVE: To confirm these beneficial effects and significant attenuation of discomfort in a randomized, controlled trial (RCT). DESIGN: Prospective RCT, intent-to-treat analysis. SETTING: Veterans Affairs ambulatory care facility. PATIENTS: Veterans undergoing scheduled unsedated colonoscopy. INTERVENTIONS: During insertion, the water and traditional air methods were compared. MAIN OUTCOME MEASUREMENTS: Discomfort and procedure-related outcomes. RESULTS: Eighty-two veterans were randomized to the air (n = 40) or water (n = 42) method. Cecal intubation (78% vs 98%) and willingness to repeat (78% vs 93%) were significantly better with the water method (P < .05; Fisher exact test). The mean (standard deviation) of maximum discomfort (0 = none, 10 = most severe) during colonoscopy was 5.5 (3.0) versus 3.6 (2.1) P = .002 (Student t test), and the median overall discomfort after colonoscopy was 3 versus 2, P = .052 (Mann-Whitney U test), respectively. The method, but not patient characteristics, was a predictor of discomfort (t = -1.998, P = .049, R(2) = 0.074). The odds ratio for failed cecal intubation was 2.09 (95% CI, 1.49-2.93) for the air group. Fair/poor previous experience increased the risk of failed cecal intubation in the air group only. The water method numerically increased adenoma yield. LIMITATIONS: Single site, small number of elderly men, unblinded examiner, possibility of unblinded subjects, restricted generalizability. CONCLUSIONS: The RCT data confirmed that the water method significantly enhanced cecal intubation and willingness to undergo a repeat colonoscopy. The decrease in maximum discomfort was significant; the decrease in overall discomfort approached significance. The method, but not patient characteristics, was a predictor of discomfort. (Clinical trial registration number NCT00747084).

Impact of a novel water method on scheduled unsedated colonoscopy in U.S. veterans.

BACKGROUND: Intermittent warm-water infusion in lieu of air insufflation permitted 52% of patients who accepted sedation on demand to complete colonoscopy without sedation. OBJECTIVE: To test the hypothesis that the water method enhances cecal intubation and increases the proportion of patients who report willingness to repeat a scheduled unsedated colonoscopy. DESIGN: Observational study. PATIENTS: Two consecutive groups of veterans. INTERVENTIONS: From June 2005 to May 2006, the usual air insufflation method was used to aid colonoscope insertion. From June 2006 to October 2007, the water method was used. MAIN OUTCOME MEASUREMENTS: Cecal intubation; report of willingness to repeat unsedated colonoscopy. RESULTS: Sixty-two and 63 veterans were examined by the air method and the water method, respectively. Intention-to-treat analysis revealed that the cecal intubation rate with the water method (97% [61/63]) was significantly higher than that with the air method (76% [47/62]). The proportion of patients who reported willingness to repeat unsedated colonoscopy was significantly higher with the water method (90% [57/63]) compared with the air method (69% [43/62]). LIMITATIONS: Single site, nonrandomized, unblinded, small number of elderly male veterans. CONCLUSION: The effects of the water method in the group for scheduled unsedated colonoscopy were sufficiently provocative to warrant calling for their confirmation by a randomized controlled trial.

Unsedated colonoscopy: time to revisit this option?

BACKGROUND: Access to potentially life-saving screening colonoscopy is limited by the high cost of sedation. We explored the practicability of having supervised trainees perform unsedated colonoscopies. METHOD: A nursing shortage at our Veterans Administration gastroenterology training program necessitated discontinuing sedated colonoscopy. We offered the procedure without sedation to restore local access to screening colonoscopy. RESULTS: From September 2002 to June 2005, 145 of 483 patients accepted the unsedated option. The procedure was done by second-year gastroenterology (GI) fellows who had performed about 100 sedated colonoscopies in their first year of training. Cecal intubation was achieved in 81% of 138 well purged patients without obstructive lesions. Implementation obviated the need for 2 registered nurses, the escort requirement, and postprocedure activity restriction. It also eliminated sedation-related complications. CONCLUSION: This report confirms the feasibility of unsedated colonoscopy performed by supervised trainees. The unsedated option minimizes direct and indirect costs of colonoscopy. Describing unsedated screening colonoscopy to patients as a "sedation risk-free" procedure encouraged them to consider the benefits. We recommend that future studies test primary care providers' willingness to inform patients of the feasibility of this nonstandard option, and perhaps reshape the practice of colonoscopy for colorectal cancer screening.