Tung-Cheng Chang1,2, Min-Hsuan Yen1, Kee-Thai Kiu1. 1. Division of Colorectal Surgery, Department of Surgery, Taipei Medical University Shuang-Ho Hospital, Number 291, Zhongzheng Road, Zhonghe District, New Taipei City, 235, Taiwan. 2. Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.