Department of Digestive Endoscopy, The First Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, China

Received 30 November 2021 Accepted 15 February 2022

Correspondence to Zhi-Ning Fan, MD, PhD, Department of Digestive Endoscopy, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, 210029, Nanjing, Jiangsu China, Tel: 86+13951965080; e-mail: [email protected]