Received: 10 December 2019
Accepted: 3 April 2020
First Online: 16 April 2020
Ethics approval and consent to participate
: This retrospective study was approved by the Ethics Committee on Human Research of the first affiliated hospital of Bengbu Medical College, and informed consent was obtained from all involved patients.
: This retrospective study was well understood and agreed by all the enrolled patients, which was recorded in the consent for publication.
: The authors declare that they have no competing interests.