Timed screening colonoscopy: a randomized trial of two colonoscopic withdrawal techniques

Area of Science:

• Gastroenterology
• Endoscopy
• Cancer Prevention

Background:

• Missed adenomas, often in the proximal colon, contribute to interval colorectal cancers.
• Increased adenoma detection rates (ADR) are linked to withdrawal times of 6 minutes or more.
• Optimal time allocation per colonic segment remains unestablished.

Purpose of the Study:

• To evaluate if fixed withdrawal times improve adenoma detection rate (ADR) compared to standard colonoscopy.
• To specifically assess the impact on detecting lesions in the proximal colon.

Main Methods:

• A randomized trial comparing fixed withdrawal times (minimum 2 min cecum/right colon, 1 min transverse, 3 min left) versus standard (≥6 min free withdrawal).
• Included 1149 patients undergoing screening colonoscopy.
• Primary outcome was ADR, with secondary analysis of proximal lesion and serrated polyp detection.

Main Results:

• No significant difference in global ADR between fixed (42.1%) and standard (39.8%) withdrawal groups.
• Multivariate analysis confirmed association of adenoma detection with higher BBPS scores, age, male sex, and longer withdrawal time, but not the technique.
• No statistical difference in detecting proximal lesions or serrated polyps between groups.

Conclusions:

• Fixed withdrawal time protocols did not enhance adenoma detection in this study.
• Study findings support previous research indicating longer withdrawal times correlate with improved adenoma detection, particularly in the proximal colon.