Received: 20 April 2019
Accepted: 4 September 2020
First Online: 14 September 2020
Ethics approval and consent to participate
: The study was approved by the institutional review board at Seoul National University Hospital and SMG-SNU Boramae Medical Center (H1710–036-891). We conducted a retrospective case study and were exempted from obtaining prior consent of the patients. The research protocol was in accordance with the Declaration of Helsinki guidelines. This study is involved at human participants. However, retrospective patient case studies have exempted patient’s informed consent.
: The authors declare that they have no competing interests.