Liang Ge, Yu Wang, Quan-Hong Duan, Guo-Jing Liu, Department of Anal and Intestinal Surgery, Affiliated Hospital of Weifang Medical University, Weifang 261031, Shandong Province, China
Song-Shan Liu, Department of Surgery, Weifang Medical College, Weifang 261031, Shandong Province, China
Author contributions: Ge L and Liu GJ designed the research, analyzed the data, and wrote the paper; Wang Y, Liu SS, and Duan QH performed the research.
Institutional review board statement: This study was reviewed and approved by the Human Ethics Committee of Affiliated Hospital of Weifang Medical College.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The ARRIVE Guidelines have been adopted.
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/
Corresponding author: Guo-Jing Liu, MD, Doctor, Department of Anus and Intestine Surgery, Affiliated Hospital of Weifang Medical University, No. 2428, Yuhe Road, Weifang 26103, Shandong Province, China. email@example.com
Telephone: +86-13081698899 Fax: +86-536-3081628
Received: September 5, 2019
Peer-review started: September 5, 2019
First decision: October 14, 2019
Revised: October 29, 2019
Accepted: November 13, 2019
Article in press: November 13, 2019
Published online: December 7, 2019