Optimal anastomotic technique in rectal surgery to prevent anastomotic leakage.

Complications after colorectal surgery remain inevitable, and anastomotic leakage is one of the most severe and potentially fatal complications. Generally, anastomotic leakage is associated with severe peritonitis, the need for emergency reoperation, and an increased mortality rate. Additionally, particularly after rectal cancer surgery, it has a negative impact on long-term outcomes, including postoperative anorectal function, local recurrence, and survival. To prevent anastomotic leakage, understanding the characteristics of each anastomotic technique and establishing a stable anastomotic procedure are important. Transanal total mesorectal excision (TaTME) is a relatively new advanced surgical access technique for pelvic dissection and facilitates different anastomotic techniques without the need for transabdominal rectal transection. Especially, stapled anastomosis in TaTME, also known as double purse-string circular stapled anastomosis or the single stapling technique (SST), has gained much attention as an alternative to the conventional double stapling technique (DST). In this article, we describe the DST, SST, and hand-sewn anastomosis as anastomotic techniques after rectal surgery, focusing mainly on the differences between conventional anastomotic techniques and SST in TaTME. Furthermore, the blood flow evaluation method for the reconstructive colon before anastomosis, which is extremely important in anastomotic leakage prevention regardless of the anastomotic type, is also described.