Transanal endoscopic microsurgery for rectal cancer / 中华胃肠外科杂志

ABSTRACT

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 local 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 prevent insufficient 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 Sm1 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.