Received: 12 April 2021
Accepted: 9 August 2021
First Online: 23 August 2021
: Written informed consent was obtained from all patients before ESD. Informed consent for study enrollment was obtained in the form of an opt-out on the website. This study protocol was approved by the ethical committee of Iwate Medical University (MH2020-169).
: Not applicable.
: The authors declare that they have no competing interests.