Funding for this research was provided by:
National Natural Science Foundation of China (81801813)
Received: 3 May 2019
Accepted: 21 November 2019
First Online: 29 November 2019
Ethics approval and consent to participate
: This single-institution retrospective study was approved by the Institutional Ethics Committee of the Second Xiangya Hospital of Central South University in accordance with Declaration of Helsinki. Due to the retrospective nature of the present study and some of patients had died, written informed consent was waived by Institutional Ethics Committee. Instead, verbal informed consent was obtained from patients or their family members.
: Not Applicable.
: The authors declare that they have no competing interests.