Received: 23 December 2020
Accepted: 11 May 2021
First Online: 21 May 2021
: Institutional review board of Nanjing Medical University approved the respective study protocol. And all methods were performed in accordance with the relevant guidelines and regulations.
: This was a retrospective study. All patients were told that their clinical data might be used for medical research and published in an online open-access publication. Informed consent for both study participation and publication of identifying information/images in an online open-access publication was obtained for each patient before surgery. No information or images that could lead to identification of a study participant was contained in this manuscript.
: The authors declare that they have no competing interests.