Funding for this research was provided by:
Linyi Science and Technology Bureau of Shandong Province (201818019)
Received: 11 October 2019
Accepted: 3 January 2020
First Online: 8 January 2020
Ethics approval and consent to participate
: This study has been approved by the Medical Ethics Committee of Linyi People’s Hospital Affiliated to Shandong University (No. 20013).
: For the 186 cases in our institution, consents for publication have been obtained from patients.
: The authors declare that they have no competing interests.