Tzu-Chi Hsu1,2,3, I-Lin Lu4,5. 1. Division of Colon and Rectal Surgery, Department of Surgery, Taipei, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. tzuchi@ms2.mmh.org.tw. 2. Department of Surgery, Taipei Medical University, Taipei, Taiwan, Republic of China. tzuchi@ms2.mmh.org.tw. 3. , #92, Section 2, Chung-San North Road, Taipei, Taiwan, Republic of China. tzuchi@ms2.mmh.org.tw. 4. Division of Colon and Rectal Surgery, Department of Surgery, Taipei, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. 5. Department of Surgery, Taipei Medical University, Taipei, Taiwan, Republic of China.