Indications for transanal minimally invasive surgery in the treatment of rectal cancer

Transabdominal, transsacral and transanal approaches are common treatments for patients with early rectal cancer. However, no matter which surgical procedure is used, including the laparoscopic surgery developed in recent years, it will have an impact on the patient's whole body, and the treatment costs and complications are relatively high.

Minimally invasive anal preservation surgery (TEM) for transanal tumor resection can combine high-quality visual systems and pressure-regulated inflatable and inspiratory devices to fully expose the rectum and lesions, and use special surgical systems for surgery, so it has been promoted clinically. TEM is suitable for the treatment of adenomas with a wide base or sessile tumors 4cm to 20cm from the anal verge, recurrent adenomas, low-risk rectal cancer (moderately differentiated to well-differentiated, T1 lesions without lymphatic and neural infiltration), fistulas, and rectal stenosis after anastomosis. It is also a suitable treatment for certain T2 and T3 rectal cancers with specific indications, such as palliative surgery for elderly or high-operative risk patients who are unwilling or unable to tolerate radical abdominal surgery and local control for patients with extensive metastases.

In addition, the diagnosis or biopsy of other benign tumors of the rectum (lipoma, leiomyoma, etc.) or benign tumors around the rectum and rectal bleeding are also one of the indications. Lesions that are too close to the anal verge (2-4 cm) are not suitable for TEM because they are not conducive to instrument placement and are prone to air leakage. In addition, the site of cancer should not be too high, otherwise it is difficult for the instrument to reach and expose, generally within 20 cm from the anus.