Text and Data Mining valid from 2020-01-14
Received: 7 August 2019
Accepted: 12 December 2019
First Online: 14 January 2020
Ethics approval and consent to participate
: Approval for this study was granted by the institutional review board of Kyung Hee University Hospital at Gangdong (KHNMC 2011–058).
: Written informed consent was obtained from all patients before surgery.
: The authors declare that they have no competing interests.