Xiangfeng Song1, Yonghui Bi2, Wei Guo3. 1. Department of Gastroenterology, Rushan Peoples Hospital, Rushan, China. 2. Department of Hepatological Surgery, Weihai Municipal Hospital, Weihai, China. 3. Department of Geratology, Jining NO.1 People's Hospital, Jining, China - guowei19811207@163.com.