探讨直肠累及齿状线的侧向发育型肿瘤（laterally spreading tumor，LST）的特点，评估内镜下黏膜剥离术（endoscopic submucosal dissection，ESD）治疗直肠累及齿状线LST的疗效及安全性。

收集2012年10月至2014年10月湖北省肿瘤医院内镜科采用ESD术治疗的45例直肠累及齿状线的LST的临床资料，回顾性分析病变类型、大小、手术时间、一次性完整切除率、并发症的发生、病理诊断、随访情况等。

45例直肠累及齿状线的LST，肿瘤直径12 mm~66 mm，平均28±15 mm，45例（100%）均一次性完整切除，ESD手时间45 min~240 min，平均100±25 min。迟发性出血6例，发生率13.3%（6/45），均行内镜下止血成功，发生术中穿孔2例，发生率4.4%（2/45），经止血夹夹闭创面后内科治疗后痊愈。术后病理诊断低级别上皮内瘤变37例，高级别上皮内瘤变8例，病变均局限于黏膜层。45例患者平均随访时间30.2个月（10~46个月），所有患者均无肿瘤复发或残留，术后排便功能正常。

ESD治疗直肠累及齿状线的LST切除彻底，安全性好，复发率低，对肛管排便功能无明显影响。

To investigate the effect and safety of endoscopic submucosal dissection (ESD) for treating rectal laterally spreading tumor (LST) extending to the dentate line.

Data of 45 cases of rectal LSTs extending to the dentate line were collected, which were treated by ESD in endoscopy center in Hubei Tumor Hospital from Oct 2012 to Oct 2014. The lesion types of LST, size, procedure time, the en-bloc complete resection rate, complications, pathological diagnosis and fellow-up were retrospective analyzed.

Among 45 LSTs in the rectum, average size of the lesion was 28 mm. en bloc R0 curative resection rate was 100%. The procedure time of ESD was 45 min~240 min, The average procedure time was (100±25) min. Delayed bleeding occurred in six patients (13.3%), all of which underwent successful endoscopic hemostasi. Perforation developed in 2 cases (4.4%), the perforation was cured by hemostat and conservative medical management. Thirty-seven cases were diagnosed post-surgically as low grade intraepithelial neoplasia and eight cases as high grade intraepithelial neoplasia, all of the lesion invasion was confined to mucosal layer. The average time of the follow-up was 30.2 months (10~46 months).None of the cases had recurrent or residual, and the anal defecation function was normal.

ESD was an effective and safe treatment for rectal LSTs for its high resection rate and low recurrence rate. ESD had no influence on the anal defecation function.