直肠下段癌采用腹会阴联合切除术(Miles 术)和上段癌采用前切除术(Dixon 术)基本已成为定论。而位于腹膜返折部位即所谓中段直肠癌,究竟采用何种手术较为适宜,目前尚有争论。至于保留肛门手术与 Miles 手术的不同点,是前者需要保留提肛肌及其水平以 The use of abdominoperineal resection (Miles) in the lower rectal cancer and anterior resection (Dixon) in the upper segment of the cancer have basically become the definitive conclusions. The peritoneal regurgitation, the so-called middle segment rectal cancer, is exactly what kind of surgery is appropriate. There is still controversy. As for the difference between anal surgery and Miles surgery, the former needs to keep the levator ani and its level.