Received: 3 January 2020
Accepted: 27 March 2020
First Online: 8 April 2020
Ethics approval and consent to participate
: The study was approved by Biomedical Ethics Sub-Committee of West China Hospital of Sichuan University (ref. 2017/48). Upon registration in West China Hospital of Sichuan University, the patients accept that their data maybe used in research. No further approval from the patients has, therefore, been sought for this study. <b>Informed consent</b>: No consent was required. Only general non-identifiable data on a series of patients is included. All data are presented on an aggregated level, and the individual patient cannot be identified.
: Not applicable.
: The authors declare that they have no competing interests.