Received: 9 August 2019
Accepted: 27 December 2019
First Online: 8 January 2020
Compliance with ethical standards
: The authors declare that they have no conflicts of interest.
: This study conformed to the ethical guidelines of the World Medical Association Declaration of Helsinki. All patients gave their written informed consent for surgery and the use of clinical data, as required by the Institutional Review Board of the Kyoto Prefectural University of Medicine (ERB-C-975–2).