经肛门微创外科手术在直肠癌的临床应用

相对于直肠癌根治术而言，直肠癌局部切除术具有手术创伤小、风险低、能保肛以及术后无性功能和泌尿功能障碍等优点。经肛门内镜微创手术（TEM）是近年来国际上较为盛行的一种直肠癌局部切除技术．同传统的局部切除术相比．TEM具有优良的术野显露和宽敞的操作空间，更配有制造精良、性能优越的多种手术器械，为外科医师在术中精细的组织解剖、精准的肿瘤切除、降低和避免肿瘤切缘不足或切缘阳性提供了极佳的手术条件和技术上的保障。术前准确评估、仔细遴选病例以及严格掌握手术指征是获得良好疗效的基础。TEM最佳的适应证为直肠腺瘤高级别瘤变（Tis期）、T1期中低危组直肠癌以及癌仅侵及sm1和sin2的患者。经过新辅助治疗后降期明显（肿块缩小大于50％者）的T，期和L期直肠癌也可进入TEM的研究性治疗。TEM术中对病灶行局部根治性切除是预防肿瘤术后复发的关键。

Transanal endoscopic microsurgery for rectal cancer

In comparison with the radical resection for rectal cancer, the local excision of rectal cancer is associated with advantages of less trauma, lower risks, anal sphincter preservation, and sexual and urinary function preservation. Being one of the 10cal excision techniques for rectal cancers, transanal endoscopic microsurgery（TEM） becomes increasingly prevailing worldwide in recent years. As compared to traditional local excision procedures, TEM has been proven to improve the operative exposure and provide more adequate operating space. In addition, the TEM is equipped with multiple well-crafted surgical instruments that offer superior performances, which allows delicate surgical dissection and precise tumor excision. TEM provides surgeons with perfect technical support to decrease the chance of or to preventinsufficient removal of the lesion, which leaves an unsafe or positive surgical margin. Good therapeutic results are based on the accurate preoperative evaluation and careful selection of the patient, as well as strict adherence to the indications of this procedure. The best indications for TEM procedure include rectal adenomas with high-grade dysplasia （Tis stage）, medium- or low-risk T1 rectal cancers, and cancers that only infiltrate into the Sml and Sm2 layers of the submucosa. Patients of T2 and T3 rectal cancers acquiring marked tumor downstaging （or tumor size decreases by more than 50% ） after the neoadjuvant therapy may also be candidates for TEM local excision in clinical research studies. TEM technique enables a locally radical excision of the lesion, which is the key to prevent the postoperative recurrence.