Comparison of Adenoma Detection Rate Between Three-dimensional and Standard Colonoscopy: A Multicenter Randomized Controlled Trial.

Background and study aim: Improvement of adenoma detection rate (ADR) effectively reduces the subsequent incidence of colorectal cancer (CRC). Three-dimensional (3D) colonoscopy provided more anatomical details than standard two-dimensional (2D) colonoscopy and improved ADR in a simulation study. We aimed to compare the ADR between 2D and 3D colonoscopy.

Patients and methods: In this multicenter randomized controlled trial, subjects aged ≥ 40 years who underwent colonoscopy for screening, surveillance, or symptoms were consecutively enrolled between February 2022 and June 2023 and randomized into 2D or 3D groups with a 1:1 ratio. The primary outcome was ADR. The secondary outcomes included the detection rates of flat adenoma, right-sided adenoma, proximal adenoma, sessile serrated lesion and advanced adenoma.

Results: Of the 348 participants recruited, 158 and 160 were allocated to 2D and 3D colonoscopy, respectively. The mucosa inspection time was comparable between the 3D (9.8±2.6 minutes) and 2D (9.4±3.1 minutes) groups (p=.21). The 3D group had significantly higher ADR (53.1% vs. 38.6%, difference (95% confidence interval, CI): 14.5% (3.7-25.4), p=.0094), as well as higher detection rates for flat adenoma (35.0% vs. 21.5%, difference: 13.5% (3.7-23.3), p=.0076), right-sided adenoma (26.3% vs. 15.2%, difference: 11.1% (2.2-19.9), p=.015), proximal adenoma (38.1% vs. 23.4%, difference: 14.7% (4.7-24.7), p=.0045) and adenoma sized 5-9mm (45.0% vs. 31.0%, difference: 14.0% (3.4-24.5), p=.010). However, there was no difference in the detection rate of sessile serrated lesion and advanced adenoma.

Conclusions: 3D colonoscopy improved the detection of adenomas without significantly increasing the mucosa inspection time. (ClinicalTrials.gov: NCT05153746).