Received: 24 October 2019
Accepted: 31 January 2020
First Online: 27 February 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Haikou Hospital affiliated with the Xiangya School of Medicine (the approval number is 2017–145), and was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Written consent was obtained from all patients.
: Not Applicable.
: The authors declare that they have no competing interests.