Article History
Received: 3 November 2019
Revised: 1 April 2020
Accepted: 21 April 2020
First Online: 6 May 2020
Compliance with ethical standards
:
: The authors declare that they have no conflicts of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors. This study was approved by the Institutional Review Board of Myongji Hospital and followed the tenets of the Declaration of Helsinki.
: This type of study does not require informed consent due to retrospective data collection.