Article History
Received: 18 January 2019
Accepted: 12 April 2019
First Online: 24 April 2019
Ethics approval and consent to participate
: The Clinical Trial Ethics Review Committee of the PLAGH Hospital approved this study. Because this study was a retrospective study and private information, such as patient name and address, was not involved in the study, formal consent was waived in our hospital.
: Not applicable.
: The authors declare that they have no competing interests.
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