Received: 2 April 2019
Accepted: 20 June 2019
First Online: 1 August 2019
Ethics approval and consent to participate
: This study was conducted in accordance with the World Medical Association Declaration of Helsinki and was approved by the institutional review board of The Jikei University (Approval number: 29-043(8659)).
: Informed consent was obtained from each patient.
: The authors declare that they have no competing interests.