Article History
Received: 30 April 2020
Accepted: 3 September 2020
First Online: 21 September 2020
Ethics approval and consent to participate
: This study was approved by the institutional review boards at West China hospital and was granted a waiver of informed consent (2019-S-361). Since this work is a retrospective study, the ethics committee did not require each patient to sign the informed consent.
: Not applicable.
: The authors declare that they have no competing interests.