Article History
Received: 11 August 2020
Accepted: 22 September 2020
First Online: 24 September 2020
Compliance with ethical standards
:
: All authors declare that no conflict of interest exists in this study.
: The study was approved by the Ethics Committee on Biomedical Research, West China Hospital of Sichuan University. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Individually informed consent was waived for this retrospective study.
: Not applicable.