Received: 28 June 2020
Accepted: 25 September 2020
First Online: 29 September 2020
Ethics approval and consent to participate
: This study accords with the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the Ethical Committee of the Fifth Medical Center of Chinese PLA General Hospital (No. 2019016D). Informed consent was waived due to the study was retrospectively designed and the data were anonymous.
: Not applicable.
: The authors declare that they have no competing interests.