Received: 3 March 2020
Accepted: 7 May 2020
First Online: 15 May 2020
Ethics approval and consent to participate
: This study has been approved by the Ethics of Committees of the Sixth Hospital of Wenzhou, and the Second Affiliated Hospital of Wenzhou Medical University, and in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed consent for participation in this retrospective study and publication was written and obtained.
: Not applicable.
: The authors declare that they have no competing interests.