Department of Pediatric Surgery, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology; Hubei Clinical Center of Hirschsprung Disease and Allied Disorders, Wuhan. Department of General Surgery, Shenzhen Children's Hospital, Guangdong. Department of Neonatal Surgery, Children's Hospital of Nanjing Medical University, Jiangsu. Department of Neonatal Surgery, Zhejiang University School of Medicine Children's Hospital, Zhejiang. Department of Pediatric Surgery, Anhui Provincial Children's Hospital, Anhui. Department of General Surgery, Tianjin Children's Hospital, Tianjin. Department of Pediatric General Thoracic and Urology Surgery, The Affiliated Hospital of Zunyi Medical University, Guizhou. Department of Surgery, Second Hospital of Hebei Medical University, Hebei. Department of General Surgery, Children's Hospital of Shanghai, Shanghai Jiao Tong University, Shanghai. Department of Neonatal Surgery, Children's Hospital of Shanxi, Shanxi. Department of Pediatric Surgery, Affiliated Hospital of Binzhou Medical College, Shandong. Department of General Surgery and Oncology, Fujian Maternity and Child Health Hospital, Affiliated Hospital of Fujian Medical University, Fujian. Department of Pediatric Surgery, First Affiliated Hospital of Xinjiang Medical University, Urumqi. Department of Pediatric Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.