Retrospective Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Nov 16, 2022; 14(11): 694-703
Published online Nov 16, 2022. doi: 10.4253/wjge.v14.i11.694
Impact of looping on premalignant polyp detection during colonoscopy
Osamu Toyoshima, Toshihiro Nishizawa, Shuntaro Yoshida, Tatsuya Matsuno, Toru Arano, Ryo Kondo, Kazunori Kinoshita, Yuki Yasumi, Yosuke Tsuji, Mitsuhiro Fujishiro
Osamu Toyoshima, Shuntaro Yoshida, Tatsuya Matsuno, Toru Arano, Ryo Kondo, Department of Gastroenterology, Toyoshima Endoscopy Clinic, Tokyo 157-0066, Japan
Toshihiro Nishizawa, Department of Gastroenterology and Hepatology, International University of Health and Welfare, Narita Hospital, Narita 286-8520, Japan
Kazunori Kinoshita, Department of Obstetrics and Gynecology, Seijo Kinoshita Hospital, Tokyo 157-0066, Japan
Yuki Yasumi, Department of Internal Medicine, Yasumi Hospital, Morioka 028-4125, Japan
Yosuke Tsuji, Mitsuhiro Fujishiro, Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
Author contributions: Toyoshima O, Nishizawa T, Yoshida S and Fujishiro M designed the study; Toyoshima O, Nishizawa T, Yoshida S, Matsuno T, Arano T, and Kondo R contributed to the endoscopic diagnosis; Toyoshima O wrote the article; Toyoshima O and Yoshida S were responsible to the statistical analysis; Nishizawa T edited the article; Yoshida S, Matsuno T, Arano T, Kondo R, Kinoshita K, Yasumi Y, Tsuji Y, and Fujishiro M involved in the critical review; and all authors approved the final manuscript.
Institutional review board statement: This study was approved by the Certificated Review Board, Yoyogi Mental Clinic on July 16, 2021 (approval no. RKK227).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent. For full disclosure, the details of the study are published on the home page of Toyoshima Endoscopy Clinic.
Conflict-of-interest statement: Fujishiro M received research grant and honoraria from Olympus Corporation.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Toshihiro Nishizawa, MD, PhD, Professor, Department of Gastroenterology and Hepatology, International University of Health and Welfare, Narita Hospital, 852 Hatakeda, Narita 286-8520, Japan. nisizawa@iuhw.ac.jp
Received: September 5, 2022
Peer-review started: September 5, 2022
First decision: October 12, 2022
Revised: October 20, 2022
Accepted: November 6, 2022
Article in press: November 6, 2022
Published online: November 16, 2022
Abstract
BACKGROUND

The presence of premalignant polyps on colonoscopy is an indicator of metachronous colorectal cancer. Looping during colonoscopy is associated with old age, female sex, and colonoscopy insertion time. However, the clinical significance of looping is not fully understood. We aimed to clarify the effect of looping on colorectal premalignant polyp detection.

AIM

To assess the effects of looping on premalignant polyp detection using logistic regression analyses.

METHODS

We retrospectively investigated patients who underwent colonoscopy at Toyoshima Endoscopy Clinic between May, 2017 and October, 2020. From the clinic’s endoscopy database, we extracted data on patient age, sex, endoscopist-assessed looping, colonoscopy duration, endoscopist experience, detection rate, and number of premalignant polyps.

RESULTS

We assessed 12259 patients (mean age, 53.6 years; men, 50.7%). Looping occurred in 54.3% of the patients. Mild and severe looping were noted in 4399 and 2253 patients, respectively. The detection rates of adenomas, advanced adenomas, high-risk adenomas, clinically significant serrated polyps (CSSPs), and sessile serrated lesions (SSLs) were 44.7%, 2.0%, 9.9%, 8.9% and 3.5%, respectively. The mean numbers of adenomas and SSLs were 0.82 and 0.04, respectively. The detection rates of adenomas, high-risk adenomas, and CSSPs increased with looping severity (all P < 0.001). The number of adenomas increased with looping severity (P < 0.001). Multivariate analyses found that detection of adenomas, high-risk adenomas, and CSSPs was associated with severe looping (P < 0.001, P < 0.001, and P = 0.007, respectively) regardless of age, sex, time required for colonoscope insertion and withdrawal, and endoscopist experience.

CONCLUSION

Looping severity was independently associated with high detection rates of premalignant polyps. Therefore, looping may predict the risk of metachronous colorectal cancer. Endoscopists should carefully examine the colorectum of patients with looping.

Keywords: Looping, Colorectal polyp, Colonoscopy, Adenoma, Serrated polyp, Colorectal neoplasm

Core Tip: This study aimed to clarify the effect of colonic looping on colorectal premalignant polyp detection during colonoscopy. We retrospectively investigated 12259 patients who underwent colonoscopies. Looping occurred in 54.3% (35.9% and 18.4% with mild and severe looping, respectively) of the cases. The detection rates of adenomas (44.7%), high-risk adenomas (9.9%), and clinically significant serrated polyps (CSSPs) (8.9%) increased with the looping severity. The number of adenomas per colonoscopy (0.82) increased with the looping severity. Multivariate analyses found that detection of adenomas, high-risk adenomas, and CSSPs was associated with severe looping regardless of age, sex, time required for colonoscope insertion and withdrawal, and endoscopist experience.