Background: The effect of retroflexed view (RV) for the reexamination of the right colon after forward view (FV) examination has not been fully understood.
Methods: We searched multiple databases including PubMed, Embase, and the Cochrane Library for prospective studies exploring the role of RV for reexamination of the right colon. A meta-analysis was performed on outcomes including lesion detection rates, lesion miss rates, and withdrawal time.
Results: Four randomized controlled trials aimed to compare the impact of the second withdrawal from the right colon in RV vs. FV following a standard colonoscopy. Both the additional adenoma detection rate (AADR) and additional polyp detection rate (APDR) of the right colon were lower in the RV group compared with the FV group (risk ratio [RR] 0.73 for AADR; RR 0.76 for APDR); similar results were noted in comparisons of the adenoma miss rate and polyp miss rate. Six prospective cohort studies aimed to describe the effect of the RV examination of the right colon after one or two rounds of FV examination. Both the adenoma detection rate (ADR) and polyp detection rate (PDR) of the right colon were slightly higher in combined examinations with RV examination than single FV examination (RR 1.11 for ADR; RR 1.16 for PDR) or two FV examinations (RR 1.21 for ADR; RR 1.22 for PDR).
Conclusions: FV may detect more adenomas and polyps than RV during the second withdrawal from the right colon. RV may detect additional adenomas and polyps in the right colon after two FV examinations.
Keywords: adenoma detection rate; colonoscopy; forward view; polyp detection rate; retroflexion.
© 2021 Japan Gastroenterological Endoscopy Society.