To explore the safety and advantages of using our new self-made transparent screw-thread anal dilator in the treatment of ultra-low rectal cancer through natural orifice specimen extraction surgery (NOSES).

Retrospective analysis of 5 cases in which patients underwent the laparoscopy combined with transanal manual anastomosis precision functional sphincter-preserving NOSES surgery (PPS) for Ultra-Low Rectal Cancer using the new screw-thread anal dilator between May 2018 to June 2018 at Gastrointestinal Surgery Department, Shanghai Tenth People's Hospital. A summary was made of the patients' operation time, intraoperative bleeding volume, length of hospital stay, complications and anal function.

The PPS for Ultra-Low Rectal Cancer was successfully completed in all 5 patients. The average operation time was (217.01±37.75) min, the average intraoperative bleeding volume was (108.32±53.15) mL, the average length of hospital stay after operation was (6.34±1.72) days, average Wexner and Vaizey scores for anal function after operation were 3 points, and no significant complications occurred after operation.

Using the new screw-thread anal dilator in the treatment of ultra-low rectal cancer through PPS has proven to be safe and effective. Incision of abdomen to extract specimen was avoided, and the surgical trauma was significantly reduced. At the same time, the lesion can be precisely resected under direct vision, with post-operative anal function being preserved and improved to a great extent, thus improving quality of life after operation. Moreover, the device is operable, economical and practical; indeed, it is worth promoting and applying in clinic. However, the above conclusions still need to be further validated by clinical studies with large sample sizes.