Segmental Withdrawal During Screening Colonoscopy Does Not Increase Adenoma Detection Rate.

Objectives: The aim of this study was to compare a standard versus segmental withdrawal during screening colonoscopy and its effect on the adenoma detection rate (ADR). Methods: We performed a single-center clinical trial of average-risk patients 50 years of age and older undergoing screening colonoscopy. Patients were randomized into four groups: a standard withdrawal of at least 6 or 8 minutes and a segmental withdrawal, in which >= 3 or >= 4 minutes were dedicated to the right side of the colon, with a minimum withdrawal time of at least 6 or 8 minutes, respectively. Results: There were 311 patients in the study. There was no difference in ADR between the standard and segmental groups (relative ratio [RR] 0.91, P = 0.50), even after stratifying for right-sided adenomas. During standard withdrawal, an increased continuous withdrawal time was associated with a higher ADR (RR 1.08, P < 0.001) and total adenomas per patient (RR 1.12, P < 0.001). A binary analysis of >= 8 minutes or <8 minutes withdrawal was associated with an increased adenomas per colonoscopy (RR 1.86, P = 0.04). These differences were not observed in the segmental group. Conclusions: Overall, there was no benefit from a segmental withdrawal protocol on ADR, but this may have been the result of the inherent limitations in the study design. After sensitivity analysis, a segmental withdrawal protocol led to an improvement in the detection of adenomas per colonoscopy and polyps per colonoscopy. A larger sample size is needed to confirm these findings.