Received: 17 July 2020
Accepted: 26 November 2020
First Online: 1 December 2020
Ethics approval and consent to participate
: This is a retrospective study and has been reviewed by the Medical Ethics Committee of Tianjin NanKai Hospital (NKYY_YX_IRB_2018_002_01). As the study was retrospective, no informed consent was required. All patients are anonymous and their information is not public.
: Not applicable.
: The authors declare that they have no competing interests.