Jun-Liang Teh, Asim Shabbir, Soon Yuen, Jimmy Bok-Yan So, Department of Surgery, National University Hospital System, Singapore 119228, Singapore
Jun-Liang Teh, Soon Yuen, Department of Surgery, Jurong Health Campus, National University Health System, Singapore 609606, Singapore
Jimmy Bok-Yan So, Department of Surgery, National University of Singapore, Singapore 119074, Singapore
Author contributions: Teh JL designed the research, performed the article search and drafted the manuscript; Shabbir A and Yuen S designed the research and proof-read the article; So JBY designed the research, performed the article search, drafted and approved the final version of the manuscript.
Conflict-of-interest statement: All the authors declare that they have no competing interests.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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 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: Jimmy Bok-Yan So, MbChB, MPH, FAMS, Professor of Surgery, Department of Surgery, National University Hospital, Level 8 Towerblock, Singapore 119228, Singapore. email@example.com
Received: October 13, 2019
Peer-review started: October 13, 2019
First decision: December 5, 2019
Revised: January 10, 2020
Accepted: January 15, 2020
Article in press: January 14, 2020
Published online: January 28, 2020