Longer Retroflexion Duration Significantly Improves Adenoma Detection Rate in the Right Colon: A Multicenter Prospective Pragmatic Clinical Trial

Abstract

Introduction: Adenoma detection rate (ADR) is a quality measure for colonoscopies. Miss rate for adenomas can be as high as 30% and lesions on the right-side of the colon are particularly high risk of getting missed. Retroflexion has been shown to improve ADR but ideal time for retroflexion is unknown. Methods: Patients above the age of 45 (or if screening was indicated prior to that), who underwent screening colonoscopy, were included. ADRR (Adenoma detection rate in the right colon), was compared when ≥ 30 seconds (s) were spent during retroflexion in the right colon (cecum up to the hepatic flexure), with when ≥ 30s were spent during retroflexion in the right colon. Results: 275 patients were included with 182 patients (66%) were included in the < 30s group and 93 patients (34%) in the ≥ 30s group Mean age was 60 years SD ± 9.9 years. 77% patients were Caucasian and 19% were African American. 55% patients were female. Median withdrawal time was 11mins, and median right colon withdrawal time (RWT) was 3.5mins. Adult colonoscope (12.8mm) was used in 77% of patients. ADR in the right colon was 36% when retroflexion was performed for ≥ 30s compared to 20% in < 30s group, p=.006. Polypectomy time was excluded if it was done in retroflexion. Polyps that were seen only on retroflexion, which could not be seen on forward view, were significantly more likely to be found in the ≥ 30s group (19%, n =16) compared to the < 30s group 3%, p< .0001. GI fellows were successful in retroflexion in 64% vs. 76% with attending physicians p=.025. Retroflexion success was 90% without looping, vs. 34% with severe looping, p< .0001. Retroflexion was successful in 55% with Boston bowel prep score of 2 compared to 75% with score of 3 in the right colon p=.021. Patients in whom retroflexion failed had a higher BMI (mean 31.9 vs. 29.4 when retroflexion failed, p=0.01). There was no difference in success of retroflexion with sex (p=.5), ASA score (p=.07), race (p=.16), indication (.7), type of colonoscope (p=.16). Looping was identified as a reason for retroflexion failure by the endoscopist in 73% of cases, narrow lumen in 4%, poor prep in 4% and type of scope/technical issues in 20% of cases. Conclusion: Adenoma detection rate in the right colon was significantly improved when retroflexion was performed for a longer duration. Barriers to successful retroflexion included looping of the colonoscope, abdominal pressure, BMI, fellow participation and bowel prep quality.182 Figure 1 No Caption available.