Article History
Received: 3 September 2019
Accepted: 12 December 2019
First Online: 26 December 2019
Ethics approval and consent to participate
: The study was allowed by the Institutional Review Committee of the Second Hospital of Shandong University and every patient signed informed consent before resection.
: Authors involved in this paper claim none of the content has not been published or is under consideration for another publication elsewhere.
: The authors declare that they have no competing interests.