Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Oct 16, 2021; 13(10): 502-509
Published online Oct 16, 2021. doi: 10.4253/wjge.v13.i10.502
Follow-up outcomes in patients with negative initial colon capsule endoscopy findings
Konosuke Nakaji, Mitsutaka Kumamoto, Mikiko Yodozawa, Kazuki Okahara, Shigeo Suzumura, Yukinori Nakae
Konosuke Nakaji, Mitsutaka Kumamoto, Mikiko Yodozawa, Kazuki Okahara, Yukinori Nakae, Endoscopy Center, Aishinkai Nakae Hospital, Wakayama-shi 640-8461, Wakayama, Japan
Shigeo Suzumura, Internal Medicine, Japanese Red Cross Urakawa Hospital, Higashichochinomi, Urakawagun Urakawacho 057-0007, Hokkaido, Japan
Author contributions: Nakaji K analyzed the data and wrote the manuscript; Nakaji K, Kumamoto M, Yodozawa M, and Okahara K performed the colon capsule endoscopy and collected the data; Suzumura S supervised the statistical analysis and Nakae Y supervised the study.
Institutional review board statement: The Ethical Review Committee at Aishinkai Nakae Hospital approved this retrospective study on February 12, 2021 (approval No. 015).
Informed consent statement: Informed consent was obtained in the form of an opt-out procedure.
Conflict-of-interest statement: The authors declare no conflicts of interest for this article.
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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Konosuke Nakaji, FACP, Doctor, Endoscopy Center, Aishinkai Nakae Hospital, 30-1 Funadokoro, Wakayama-shi 640-8461, Wakayama, Japan. parupurikopui@yahoo.co.jp
Received: April 28, 2021
Peer-review started: April 28, 2021
First decision: June 17, 2021
Revised: July 8, 2021
Accepted: September 14, 2021
Article in press: September 14, 2021
Published online: October 16, 2021
Processing time: 169 Days and 0.2 Hours
Abstract
BACKGROUND

Colon capsule endoscopy (CCE), which became clinically applicable in 2006, is a simple and noninvasive procedure to evaluate colonic diseases; the accuracy of second-generation CCE, introduced in 2009, has dramatically improved. Currently, CCE is used as an alternative method for colorectal cancer screening, as well as for evaluating the mucosal lesions of inflammatory bowel disease, in cases where performing colonoscopy (CS) is difficult. However, the outcomes of CCE are uncertain.

AIM

To investigate the outcomes of Japanese patients with negative findings (no polyps or colorectal cancer) on initial CCE.

METHODS

This retrospective, single-center study was conducted at the Endoscopic Center at Aishinkai Nakae Hospital. This study included patients who underwent continuous CCE between November 2013 and August 2019, that exhibited no evidence of polyps or colorectal cancer at the initial CCE, and could be followed up using either the fecal immunochemical test (FIT), CS, or CCE. The observational period, follow-up method, presence or absence of polyps and colorectal cancer, pathological diagnosis, and number of colorectal cancer deaths were evaluated.

RESULTS

Thirty-one patients (mean age, 60.4 ± 15.6 years; range, 28–84 years; 14 men and 17 women) were enrolled in this study. The reasons for performing the first CCE were screening in 12, a positive FIT in six, lower abdominal pain in nine, diarrhea in two, and anemia in two patients. The mean total water volume at the time of examination was 3460 ± 602 mL (2250–4800 mL), and a total CS was performed in 28 patients (90%). The degree of cleanliness was excellent in 15 patients and good in 16, and no poor cases were observed. No adverse events, such as retention or capsule aspiration, were observed in any of the patients. The mean follow-up period was 3.1 ± 1.5 years (range, 0.3–5.5 years). Follow-up included FIT in nine, CS in 20, and CCE in four patients (including duplicate patients). The FIT was positive in two patients, while CS revealed five polyp lesions (three in the ascending colon, one in the transverse colon, and one in the descending colon), with sizes ranging between 2 mm and 8 mm. Histopathological findings revealed a hyperplastic polyp in one patient, and adenoma with low grade dysplasia in four patients; colorectal cancers were not recognized. In the follow-up example by CCE, polyps and colorectal cancer could not be recognized. During the follow-up period, there were no deaths due to colorectal cancer in any of the patients.

CONCLUSION

We determined the outcomes in patients with negative initial CCE findings.

Keywords: Colon capsule endoscopy; Negative findings; Observation; Colorectal polyps; Colorectal cancer; Colorectal cancer death

Core Tip: Colon capsule endoscopy is becoming popular as a screening test for colorectal cancer in patients where colonoscopy is difficult. Its accuracy is comparable to that of colonoscopy; however, the outcomes are unknown. This study evaluated the follow-up methods, presence or absence of polyps and colorectal cancer, and cancer deaths after follow-up in Japanese patients with negative capsule endoscopy findings.