Article History
Received: 25 April 2018
Accepted: 29 October 2018
First Online: 21 November 2018
Ethics approval and consent to participate
: This study was performed in accordance with the principles of the Declaration of Helsinki and has been approved by the Institutional Review Board of Kaohsiung Veterans General Hospital. (IRB No: VGHKS14-CT12–-05). A waiver of consent was granted given the retrospective nature of the project and anonymous analysis of the data.
: Not applicable.
: The authors declare no competing interest and have nothing to disclose.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.