Funding for this research was provided by:
National Natural Science Foundation of China (81200865)
Health and Family Planning Commission of Sichuan Province (17PJ370)
Article History
Received: 27 December 2017
Accepted: 17 October 2018
First Online: 7 November 2018
Ethics approval and consent to participate
: The study was approved by the institutional ethics committee of West China Hospital Sichuan University (Chengdu, China). Written informed consent about the study protocol was obtained from each patient preoperatively.
: Not applicable.
: The authors declare that they have no competing interests.
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