1. Clinical Research Center, The Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, Guangdong Province, PR China
2. Department of Gastroenterology, The Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, Guangdong Province, PR China
3. Department of Cardiac Surgery, The Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, Guangdong Province, PR China
4. Department of Gastrointestinal Surgery, The Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, Guangdong Province, PR China