Article History
Received: 28 June 2018
Accepted: 17 October 2018
First Online: 25 October 2018
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest related to this study.
: This study was approved by the institutional review board of Korea University Guro Hospital (ID: KUGH17095).
: Acquisition of informed consent was not applicable to this study.