Comparing size measurement of colorectal polyps using a novel virtual scale endoscope, endoscopic ruler or forceps: A preclinical randomized trial

Abstract

Background and Aims: Accurate polyp size measurement is important for guideline conforming choice of polypectomy techniques and subsequent surveillance interval assignments. Some endoscopic tools (biopsy forceps [BF] or endoscopic rulers [ER]) exist to help with visual size estimation. A virtual scale endoscope (VSE) has been developed that allows superimposing a virtual measurement scale during live endoscopies. Our aim was to evaluate the performance of VSE when compared to ER and BF-based measurement. Methods: We conducted a preclinical randomized trial to evaluate the relative accuracy of size measurement of simulated colorectal polyps when using: VSE, ER, and BF. Six endoscopists performed 60 measurements randomized at a 1:1:1 ratio using each method. Primary outcome was relative accuracy in polyp size measurement. Secondary outcomes included misclassification of sizes at the 5, 10, and 20mm thresholds. Results: A total of 360 measurements were performed. The relative accuracy of BF, ER, and VSE was 78.9% (95%CI=76.2-81.5), 78.4% (95%CI=76.0-80.8), and 82.7% (95%CI=80.8-84.8). VSE had significantly higher accuracy compared to BF (p=0.02) and ER (p=0.006). VSE misclassified a lower percentage of polyps >5mm as ≤5mm (9.4%) compared to BF (15.7%) and ER (20.9%). VSE misclassified a lower percentage of ≥20mm polyps as <20mm (8.3%) compared with BF (66.7%) and ER (75.0%). 25.6%, 25.5%, and 22.5% of polyps ≥10mm were misclassified as <10mm with ER, BF, and VSE, respectively. Conclusions: VSE had significantly higher relative accuracy in measuring polyps compared to ER or biopsy forceps assisted measurement. VSE improves correct classification of polyps at clinically important size thresholds.

Measuring size of smaller colorectal polyps using a virtual scale function during endoscopies

“…Furthermore, we found that when using VSE, the percentage of size measurements that were within 25% of true size is more than doubled and significancy higher. The relative accuracies obtained for visual size estimation and VSE closely resemble those reported in preclinical trials obtained in simulated colon models 6–8. Similar to these preclinical studies, we found in our clinical pilot study that when using VSE the relative accuracy of polyp size measurement is increased from about 60%–70% (when using visual size estimation) to about 85% 6.…”

A real-time deep learning-based system for colorectal polyp size estimation by white-light endoscopy: development and multicenter prospective validation

“…A visual scale is then displayed on the screen. Endoscopists who used VSE achieved higher relative accuracy compared with visual estimation (85.4% vs. 66.8%; P <0.001) [25,26]. However, the virtual scale can only display on the right side of the laser, which potentially limits the usage scenario to measuring horizontally in the vertical plane.…”

New horizons in polyp size estimation

“…This ruler is automatically deployed onto the mucosa with reference to the distance between the tip of the endoscope and the mucosal surface where the laser light is shed on. This ruler-based measurement outperformed biopsy forceps-based measurement in a recently published preclinical trial [5].…”

“…The year 2023 has been a remarkable year for polyp size measurement, with the emergence of new technologies that can possibly help endoscopists estimate polyp size in a more accurate way than previously. These innovative technologies include both hardware-and software-based approaches [5,6].Recently, Fujifilm Corporation provided a laser-based measurement device on the market. With the use of a special endoscope integrated with a laser function (SCALE EYE; Fujifilm Corp., Tokyo), the endoscopy processor lays a ruler over the…”