Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 21, 2016; 22(11): 3220-3226
Published online Mar 21, 2016. doi: 10.3748/wjg.v22.i11.3220
Is forceps more useful than visualization for measurement of colon polyp size?
Jae Hyun Kim, Seun Ja Park, Jong Hoon Lee, Tae Oh Kim, Hyun Jin Kim, Hyung Wook Kim, Sang Heon Lee, Dong Hoon Baek, Busan Ulsan Gyeongnam Intestinal Study Group Society (BIGS)
Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea
Jong Hoon Lee, Department of Gastroenterology, Dong-A University College of Medicine, Busan 602-702, South Korea
Tae Oh Kim, Department of Gastroenterology, Haeundae Paik Hospital, Inje University College of Medicine, Busan 602-702, South Korea
Hyun Jin Kim, Department of Gastroenterology, Gyeongsang National University Hospital, Jinju 660-702, South Korea
Hyung Wook Kim, Department of Gastroenterology, Pusan National University Yangsan Hospital, Yangsan 626-770, South Korea
Sang Heon Lee, Department of Gastroenterology, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan 602-702, South Korea
Dong Hoon Baek, Department of Gastroenterology, Pusan National University School of Medicine, Busan 602-702, South Korea
Author contributions: Kim JH and Park SJ designed study; Kim JH wrote the paper; Lee JH, Kim TO, Kim HJ, Kim HW, Lee SH and Baek DH critically reviewed the manuscript for important intellectual content; Members of BIGS participated in this study; and Park SJ approved the manuscript.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of Kosin University Gospel Hospital.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors declare no conflicts of interest.
Data sharing statement: Technical appendix and dataset available from the corresponding author at parksj6406@daum.net.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Seun Ja Park, MD, Division of Gastroenterology, Department of Internal Medicine, Kosin University College of Medicine, 34 Amnam-dong, Seo-gu, Busan 602-702, South Korea. parksj6406@daum.net
Telephone: +82-51-9905061 Fax: +82-51-9905055
Received: April 29, 2015
Peer-review started: May 6, 2015
First decision: August 26, 2015
Revised: September 3, 2015
Accepted: November 9, 2015
Article in press: November 9, 2015
Published online: March 21, 2016
Abstract

AIM: To identify whether the forceps estimation is more useful than visual estimation in the measurement of colon polyp size.

METHODS: We recorded colonoscopy video clips that included scenes visualizing the polyp and scenes using open biopsy forceps in association with the polyp, which were used for an exam. A total of 40 endoscopists from the Busan Ulsan Gyeongnam Intestinal Study Group Society (BIGS) participated in this study. Participants watched 40 pairs of video clips of the scenes for visual estimation and forceps estimation, and wrote down the estimated polyp size on the exam paper. When analyzing the results of the exam, we assessed inter-observer differences, diagnostic accuracy, and error range in the measurement of the polyp size.

RESULTS: The overall intra-class correlation coefficients (ICC) of inter-observer agreement for forceps estimation and visual estimation were 0.804 (95%CI: 0.731-0.873, P < 0.001) and 0.743 (95%CI: 0.656-0.828, P < 0.001), respectively. The ICCs of each group for forceps estimation were higher than those for visual estimation (Beginner group, 0.761 vs 0.693; Expert group, 0.887 vs 0.840, respectively). The overall diagnostic accuracy for visual estimation was 0.639 and for forceps estimation was 0.754 (P < 0.001). In the beginner group and the expert group, the diagnostic accuracy for the forceps estimation was significantly higher than that of the visual estimation (Beginner group, 0.734 vs 0.613, P < 0.001; Expert group, 0.784 vs 0.680, P < 0.001, respectively). The overall error range for visual estimation and forceps estimation were 1.48 ± 1.18 and 1.20 ± 1.10, respectively (P < 0.001). The error ranges of each group for forceps estimation were significantly smaller than those for visual estimation (Beginner group, 1.38 ± 1.08 vs 1.68 ± 1.30, P < 0.001; Expert group, 1.12 ± 1.11 vs 1.42 ± 1.11, P < 0.001, respectively).

CONCLUSION: Application of the open biopsy forceps method when measuring colon polyp size could help reduce inter-observer differences and error rates.

Keywords: Colon polyp, Colonoscopy, Measurement, Endoscopy

Core tip: Using open biopsy forceps is known to be a useful technique to reduce error rates in colon polyp size measurements, but in practice most endoscopists just measure polyp size by visualization. There is little information about accuracy differences between these two methods. In this study, we showed that the inter-observer difference, diagnostic accuracy, and error range of forceps estimation were better than those of visual estimation in the measurement of the polyp size. We propose that forceps estimation should be considered to measure the colon polyp size before removing the polyp.