Expert endoscopist assessment of colorectal polyp size using virtual scale endoscopy, visual or snare-based estimation: a prospective video-based study

Abstract

Background and aims

Accurate polyp size estimation during colonoscopy has an impact on clinical decision-making. A laser-based virtual scale endoscope (VSE) is available to allow measuring polyp size using a virtual adaptive scale. This study evaluates video-based polyp size measurement accuracy among expert endoscopists using either VSE or visual assessment (VA) with either snare as reference size or without any reference size information.

Methods

A prospective, video-based study was conducted with 10 expert endoscopists. Video sequences from 90 polyps with known reference size (fresh specimen measured using calipers) were distributed on three different slide sets so that each slide set showed the same polyp only once with either VSE, VA or snare-based information. A slide set was randomly assigned to each endoscopist. Endoscopists were asked to provide size estimation based on video review.

Results

Relative accuracies for VSE, VA, and snare-based estimation were 75.1% (95% CI [71.6–78.5]), 65.0% (95% CI [59.5–70.4]) and 62.0% (95% CI [54.8–69.0]), respectively. VSE yielded significantly higher relative accuracy compared to VA (p = 0.002) and to snare (p = 0.001). A significantly lower percentage of polyps 1–5 mm were misclassified as >5 mm using VSE versus VA and snare (6.52% vs. 19.6% and 17.5%, p = 0.004) and a significantly lower percentage of polyps >5 mm were misclassified as 1–5 mm using VSE versus VA and snare (11.4% vs. 31.9% and 14.9%, p = 0.038).

Conclusions

Endoscopists estimate polyp size with the highest accuracy when virtual adaptive scale information is displayed. Using a snare to assist sizing did not improve measurement accuracy compared to displaying visual information alone.

Keywords:

• Colorectal cancer
• prevention & control
• colonoscopy
• polyps
• endoscopy, gastrointestinal

Clinicaltrials.gov:

• NCT05236790

Author contributions

Ioana Popescu Crainic: Study design; data collection; statistical analysis, analysis, and interpretation of data; drafting of the manuscript; critical revision of the manuscript for important intellectual content. Roupen Djinbachian: Study design; statistical analysis; analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Douglas K. Rex: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Alan Barkun: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Aasma Shaukat: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. James East: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Cesare Hassan: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Yuichi Mori: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Heiko Pöhl: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Amit Rastogi: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Prateek Sharma: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Joseph C. Anderson: Analysis and interpretation of data; critical revision of the manuscript for important intellectual content. Mahsa Taghiakbari: Statistical analysis, analysis and interpretation of data, critical revision of the manuscript for important intellectual content. Edgard Medawar: Statistical analysis, analysis and interpretation of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content. Daniel von Renteln: Study concept and design; Data collection; analysis and interpretation of data; critical revision of the manuscript for important intellectual content.

Disclosure statement

Ioana Popescu Crainic, Roupen Djinbachian, Douglas K Rex, Alan Barkun, Aasma Shaukat, Cesare Hassan, Yuichi Mori, Heiko Pohl, Prateek Sharma, Joseph C Anderson, Mahsa Taghiakbari and Edgard Medawar have no conflict of interest relevant to this paper to declare. James East (JEE) has ownership interest from Satisfai Health and speaker fees from Medtronic Corp. JEE is funded by the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the National Health Service, the NIHR or the Department of Health. Amit Rastogi has received research funding and is a consultant for Olympus and Boston Scientific. He is also a consultant for Cook Endoscopy. Daniel von Renteln has received speaker honoraria and research funding from Fujifilm.

Additional information

Funding

This study was funded by Fujifilm Corporation.