taTME

taTME, or transanal total mesorectal excision, is a surgical technique for the treatment of mid- to low-rectal cancer that combines transanal dissection with conventional abdominal dissection to remove the rectum and mesorectum as a single specimen from the bottom up. The procedure uses a transanal access platform (such as TEM or TAMIS) to mobilize the distal rectum and perform dissection of the mesorectal envelope, followed by proximal mobilization and specimen extraction through the anus or via a transabdominal route. A two-team approach is commonly employed, and the operation ends with reconstruction of the bowel, typically via primary anastomosis or ileostomy as clinically indicated.

Indications for taTME include low-lying rectal cancers located in a narrow or difficult pelvic geometry, obesity, prior pelvic irradiation, or cases where distal margins are challenging with conventional approaches. Proponents cite potential advantages in visualization, distal margin control, and sphincter preservation.

Evidence on outcomes is mixed. Some studies and reviews report favorable margins, lymph node yields, and comparable survival to conventional TME, while others have raised concerns about local recurrence and functional complications associated with taTME, particularly when performed without standardized training and quality control. The technique has a steep learning curve and specific risks include urethral injury, anastomotic leakage, and pelvic sepsis in some settings.

Training and quality assurance are emphasized in many centers, with international registries and structured proctoring used to monitor outcomes. Adoption varies by country and institution, reflecting ongoing debate about safety, efficacy, and the role of taTME in rectal cancer care.