Measuring size of colorectal polyps using a virtual scale endoscope or visual assessment: A randomized controlled trial.

BACKGROUND: This study aimed to compare the accuracy of polyp size measurements using a virtual scale endoscope (VSE) with an integrated laser-based adaptive scale function and visual assessment (VA) during colonoscopies.

METHODS: We conducted a single-blinded, prospective randomized controlled trial. Eligible patients (aged 45-80 years) undergoing screening, surveillance or diagnostic colonoscopies were randomly assigned (1:1) into two groups. In the intervention group, all detected polyps were measured for size using VSE; in the control group, all polyps were measured using VA. Size measurements were compared to a reference standard of digital caliper measurement immediately post-polypectomy. The primary outcome was the relative accuracy of real-time VSE measurement compared to VA. Secondary outcomes included the mean differences and the correlations between VSE or VA sizes with the reference standard of measurement.

RESULTS: Overall, 230 patients were enrolled and randomized. The relative size measurement accuracy of VSE was 84% in 118 polyps, which was significantly higher than that of VA (105 polyps; 68.4%, p<0.001). VSE resulted in a significantly higher percentage of size measurements within 25% of true size compared to VA (81.4% vs. 41%, p<0.001). VSE had a significantly lower percentage for >5mm polyps incorrectly sized as 1-5mm compared to VA (13.5% vs. 57.1%; p<0.001) and a significantly lower percentage for >3mm polyps incorrectly sized as 1-3mm compared to VA (11.3% vs. 56.5%; p<0.001).

CONCLUSIONS: VSE significantly improves the size measurement accuracy of colorectal polyps during colonoscopies compared to VA and results in fewer misclassifications at relevant decision-making size thresholds.