Randomized Controlled Trial
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2016; 22(48): 10673-10679
Published online Dec 28, 2016. doi: 10.3748/wjg.v22.i48.10673
Effects of premedication with Pronase for endoscopic ultrasound of the stomach: A randomized controlled trial
Guo-Xin Wang, Xiang Liu, Sheng Wang, Nan Ge, Jin-Tao Guo, Si-Yu Sun
Guo-Xin Wang, Xiang Liu, Sheng Wang, Nan Ge, Jin-Tao Guo, Si-Yu Sun, Endoscopy Center, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
Author contributions: Wang GX and Sun SY were involved in the study conception and design; Wang GX drafted the article and analyzed and interpreted the data; Liu X performed critical revision of the article for important intellectual content and collected data; Wang S performed the endoscopic procedure and statistical analysis; Ge N and Guo JT conducted the EUS imaging evaluation; all authors provided approval of the final article.
Supported by the National Natural Science Foundation of China, No. 81470908.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of Shengjing Hospital of China Medical University.
Clinical trial registration statement: The trial was registered in the Chinese Clinical Trial Registry (www.chictr.org.cn). The registration identification number is ChiCTR-DPD-15006240.
Informed consent statement: All study participants provided informed written consent prior to study enrollment.
Conflict-of-interest statement: None of the authors have any competing interests or financial ties to disclose.
Data sharing statement: The technical appendix, statistical code, and data set are available from the corresponding author.
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: Si-Yu Sun, MD, PhD, Professor, Endoscopy Center, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Shenyang 110004, Liaoning Province, China. sun-siyu@163.com
Telephone: +86-024-9661526111
Received: October 13, 2016
Peer-review started: October 14, 2016
First decision: November 14, 2016
Revised: November 22, 2016
Accepted: November 23, 2016
Article in press: November 28, 2016
Published online: December 28, 2016

To analyze the effects of premedication with Pronase for endoscopic ultrasound (EUS) examination of the stomach.


This was a prospective, randomized and controlled clinical study. All patients were randomly assigned to either the Pronase group or placebo group. The pretreatment solution was a mixed solution of 20000 U of Pronase and 60 mL sodium bicarbonate solution in the Pronase group, while an equal amount of sodium bicarbonate solution was administered to the placebo group. All operators, image evaluators and experimental recorders in EUS did not participate in the preparation and allocation of pretreatment solution. Two blinded investigators assessed the obscurity scores for the EUS images according to the size of artifacts (including ultrasound images of the gastric cavity and the gastric wall). Differences in imaging quality, the duration of examination and the usage of physiological saline during the examination process between the Pronase group and the control group were compared.


No differences existed in patient demographics between the two groups. For the gastric cavity, the Pronase group had significantly lower mean obscurity scores than the placebo group (1.0476 ± 0.77 vs 1.6129 ± 0.96, respectively, P = 0.000). The mean obscurity scores for the gastric mucosal surface were significantly lower in the Pronase group than the placebo group (1.2063 ± 0.90 vs 1.7581 ± 0.84, respectively, P = 0.001). The average EUS procedure duration for the Pronase group was 11.60 ± 3.32 min, which was significantly shorter than that of the placebo group (13.13 ± 3.81 min, P = 0.007). Less saline was used in the Pronase group than the placebo group, and the difference was significant (417.94 ± 121.38 mL vs 467.42 ± 104.52 mL, respectively, P = 0.016).


The group that had Pronase premedication prior to the EUS examination had clearer images than the placebo group. With Pronase premedication, the examination time was shorter, and the amount of saline used during the EUS examination was less.

Keywords: Artifacts, Randomized controlled trial, Endosonography, Pronase, Stomach

Core tip: Previous studies have confirmed that Pronase can improve the quality of endoscopic ultrasound (EUS) images. Based on previous findings, this study hypothesized that Pronase could further shorten the duration of examination and reduce the usage of physiological saline during EUS examination through improving the quality of EUS images. Moreover, this study verified this hypothesis. This study found that for EUS examination, preoperative application of Pronase could provide clearer ultrasound images, shorten the duration of EUS examination, and reduce the intraoperative usage of physiological saline.