Received: 18 October 2017
Accepted: 23 February 2018
First Online: 27 February 2018
Ethics approval and consent to participate
: This study was conducted in accordance with the Declaration of Helsinki. This study protocol was approved by the institutional review board of Kitakyushu Municipal Medical Center on November 18, 2016. Written informed consent was obtained from all patients before ESD.
: Not applicable
: The authors declare that they have no competing interests.
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