Randomized Clinical Trial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 28, 2015; 21(8): 2483-2489
Published online Feb 28, 2015. doi: 10.3748/wjg.v21.i8.2483
Effect of pronase as mucolytic agent on imaging quality of magnifying endoscopy
Gwang Ha Kim, Yu Kyung Cho, Jae Myung Cha, Sun-Young Lee, Il-Kwun Chung
Gwang Ha Kim, Department of Internal Medicine, Pusan National University School of Medicine, Pusan 602-739, South Korea
Yu Kyung Cho, Department of Internal Medicine, The Catholic University of Korea, Seoul 137-701, South Korea
Jae Myung Cha, Department of Internal Medicine, Kyung Hee University Hospital at Gang Dong, Seoul 134-727, South Korea
Sun-Young Lee, Department of Internal Medicine, Konkuk University Medical Center, Seoul 134-727, South Korea
Il-Kwun Chung, Department of Internal Medicine, Soonchunhyang University, Cheonan 330-090, South Korea
Author contributions: All the authors contributed to this manuscript.
Supported by Research grant from Pharmbio Korea, Co. Ltd., Seoul, South Korea.
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: Yu Kyung Cho, Associate Professor, Department of Internal Medicine, The Catholic University of Korea, 505 Banpodong, Seochogu, Seoul St. Mary’s Hospital, Seoul 137-701, South Korea. ykcho@catholic.ac.kr
Telephone: + 82-2-22586024 Fax: + 82-2-22582055
Received: July 30, 2014
Peer-review started: July 31, 2014
First decision: August 15, 2014
Revised: September 14, 2014
Accepted: November 30, 2014
Article in press: December 1, 2014
Published online: February 28, 2015
Abstract

AIM: To investigate the efficacy of premedication with pronase, a proteolytic enzyme, in improving image quality during magnifying endoscopy.

METHODS: The study was of a blinded, randomized, prospective design. Patients were assigned to groups administered oral premedication of either pronase and simethicone (Group A) or simethicone alone (Group B). First, the gastric mucosal visibility grade (1-4) was determined during conventional endoscopy, and then a magnifying endoscopic examination was conducted. The quality of images obtained by magnifying endoscopy at the stomach and the esophagus was scored from 1 to 3, with a lower score indicating better visibility. The endoscopist used water flushes as needed to obtain satisfactory magnifying endoscopic views. The main study outcomes were the visibility scores during magnifying endoscopy and the number of water flushes.

RESULTS: A total of 144 patients were enrolled, and data from 143 patients (M:F = 90:53, mean age 57.5 years) were analyzed. The visibility score was significantly higher in the stomach following premedication with pronase (73% with a score of 1 in Group A vs 49% in Group B, P < 0.05), but there was no difference in the esophagus visibility scores (67% with a score of 1 in Group A vs 58% in Group B). Fewer water flushes [mean 0.7 ± 0.9 times (range: 0-3 times) in Group A vs 1.9 ± 1.5 times (range: 0-6 times) in Group B, P < 0.05] in the pronase premedication group did not affect the endoscopic procedure times [mean 766 s (range: 647-866 s) for Group A vs 760 s (range: 678-854 s) for Group B, P = 0.88]. The total gastric mucosal visibility score was also lower in Group A (4.9 ± 1.5 vs 8.3 ± 1.8 in Group B, P < 0.01).

CONCLUSION: The addition of pronase to simethicone premedication resulted in clearer images during magnifying endoscopy and reduced the need for water flushes.

Keywords: Pronase, Narrow-band imaging, Endoscopy, Image enhancement, Randomized controlled trial

Core tip: Magnifying endoscopy is typically used to detect and diagnose small upper gastrointestinal tract cancers. Premedication with the proteolytic enzyme pronase improved the quality of magnified endoscopic images and required fewer water flushes to achieve satisfactory endoscopic viewing. It is unclear if the use of pronase will influence cancer detection rates or patient outcomes. However, pronase can be considered as a method of maximizing the diagnostic efficacy of high-resolution endoscopic techniques.