Yanqin Xu, MD, Fenghua Su, MD, Wei Liang, MD ⁎ 
Department of Digestive Endoscopy, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, Fuzhou, China
∗ Corresponding author: Wei Liang, MD, PhD, Department of Digestive Endoscopy, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou University Affiliated Provincial Hospital, 134 Dong Street, Fuzhou 350001, Fujian, China. Department of Digestive Endoscopy Shengli Clinical Medical College of Fujian Medical University Fujian Provincial Hospital Fuzhou University Affiliated Provincial Hospital 134 Dong Street Fuzhou Fujian 350001 China