Received: 23 February 2019
Accepted: 24 October 2019
First Online: 25 November 2019
Ethics approval and consent to participate
: Chonnam National University Hospital Institutional Review Board approved the patient record review and all data collected. The reference number for the project was CNUH-2014-218. For this type of study, formal consent was not required, and the Chonnam National University Hospital Institutional Review Board approved this.
: Not applicable.
: The authors declare that they have no competing interests.