直肠癌根治术,近30多年来虽经各方面努力,包括术式的改进,从直肠淋巴流向研究直肠癌淋巴转移,及其清扫术的改进等,5年的生存率并无明显提高,仍徘徊在30～50%。但目前国内外学者对如何保留肛门和原位人工肛门重建术的研究取得了一定的进展。直肠的分段直肠可分三段:上段为距肛缘12～15cm,中段为7.5～12cm,下段为3.7～7.5cm。上段为定型的经典 Dixon Although the radical resection of rectal cancer has undergone various efforts in the past 30 years, including the improvement of surgical methods, the study of lymphatic flow from rectal lymphatic flow to the study of lymphatic metastasis of rectal cancer, and improvement of its dissection, the 5-year survival rate has not improved significantly. It is 30 to 50%. However, current domestic and foreign scholars have made some progress in the study of how to retain the anus and in situ reconstruction of the artificial anus. The segmental rectum of the rectum can be divided into three segments: the upper segment is 12 to 15 cm from the anal margin, the middle segment is 7.5 to 12 cm, and the lower segment is 3.7 to 7.5 cm. The last paragraph is the classic Dixon