Adenoma detection at colonoscopy by polypectomy in withdrawal only versus both insertion and withdrawal: a randomized controlled trial

Colonic configuration during insertion phase (IP) and withdrawal phase (WP) is different and some polyps seen during IP are difficult to find during WP and vice versa. To determine if polypectomy performed during both IP and WP of colonoscopy (study arm) increases adenoma detection rate (ADR) compared to WP only (control arm). In this prospective randomized controlled trial, adults undergoing out-patient colonoscopy were enrolled. The primary outcome was mean number of adenomas detected per patient. Secondary outcomes were ADR, defined as the proportion of colonoscopies with at least one adenoma, polyp detection rates (PDR), number of patients classified as high-risk group (presence of ≥3 adenomas of any size, any adenoma ≥1 cm in size, or adenoma with villous component, or high grade dysplasia), procedural times, patients discomfort, and ease of procedure. Among 772 patients enrolled, 610 were included (329 in study arm and 281 in control arm). In both arms, mean number of adenomas detected per patient were similar, 0.78 ± 1.4 vs. 0.74 ± 1.5, P = 0.75. Also, ADR (39.2 vs. 38.1 %, P = 0.77) and PDR (57.1 and 54.1 %, P = 0.45) were similar. Mean insertion time was significantly higher in study arm (10.2 ± 5.8 vs. 9.3 ± 5.6 min, p = 0.046). Proportion of patients identified as high-risk group were significantly higher in study arm (18.8 vs. 11.7 %, P = 0.016). Conclusions: Polypectomy performed during both IP and WP compared to the WP only, did not improve ADR or mean number of adenomas detected per patient. Trial registration: Clinicaltrials.gov, #NCT01025960.