全直肠系膜切除 (TME)是直肠中下 2 / 3的直肠癌的手术原则方式。主要目标 :切除直肠癌及其周围淋巴结 (它们是肿瘤细胞淋巴引流的第一站 ) ,同时保存直肠系膜外结构的完整性 ,尤其是神经纤维 (它们支配膀胱、前列腺或阴道 )。本研究在于明确直肠系膜及盆腔侧壁上淋巴结的分布 Total mesorectal excision (TME) is a surgical principle of rectal cancer in the middle and lower rectum 2/3. Main goals: Resection of colorectal cancer and its surrounding lymph nodes, the first stop of lymphatic drainage of tumor cells, while preserving the integrity of rectal mesangial structures, especially nerve fibers (which dominate the bladder, prostate or vagina). This study is to clarify the distribution of lymph nodes in the mesorectum and pelvic wall