Article History
Received: 19 June 2018
Revised: 14 September 2018
Accepted: 2 October 2018
First Online: 9 November 2018
Compliance with ethical standards
:
: The scientific guarantor of this publication is Zi-shu Zhang.
: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
: No complex statistical methods were necessary for this paper.
: Written informed consent was obtained from all subjects (patients) in this study.
: Institutional Review Board approval was obtained.
: • retrospective• cross sectional study• performed at one institution