Significance and methods of distal rectal irrigation in rectal cancer surgery        WANG Hao，SHI Yun-jie. Department of Colorectal Surgery, Changhai Hospital, Naval Medical University, Shanghai 200433, China
Corresponding author: WANG Hao，E-mail：wanghaohh@
vip.126.com
Abstract    Intraoperative rectal washout（IORW）refers to irrigation and separation of the distal rectum by blocking the rectal cavity below the distal end of the tumor after full mobilization of the rectum.IORW has long been recognized as a key step in anal preservation surgery for rectal cancer，as well as an important part of aseptic and disease-free operation in radical surgery for rectal cancer.A large number of studies have found the existence of tumor cells in the distal rectal rinse fluid，and IORW can reduce the local recurrence rate of rectal cancer after surgery.Knowing that radical resection for colorectal cancer has entered the era of minimally invasive surgery，some scholars have questioned the value of IORW.As most relevant studies are of retrospective nature with low quality evidence and IORW is difficult to be performed in laparoscopy-assisted radical resection of rectal cancer，we suppose that the difficulty with IORW in low rectal cancer minimally invasive anal preservation surgery and the irrigation problem could be solved by pull-through surgery or taTME surgery.It needs to be emphasized that IORW is even more important in taTME surgery because the purpose of this transanal surgical procedure is not only for the completion of anastomosis but for the completion of mesorectal mobilization via laparoscopic-assisted taTME surgery，or the completion of the entire abdominal and pelvic procedures via pure taTME surgery.Without IORW，taTME surgery may lead to local recurrence or even serious consequences of abdominal and pelvic implants. The core technology of IORW mainly includes the blocking technique，the type of rinse fluid and the rinse volume.Among them，we believe that the blocking technique is the most important.Different blocking techniques can be selected for different surgical methods.The most common blocking technique in laparoscopy-assisted radical resection of low rectal cancer is the use of the two-piece blocking forceps.Irrigation can be performed under direct vision in pull-through surgery.The bowel cavity is blocked by purse-suturing in taTME operation.It should be emphasized that purse-suturing for taTME surgery must be reliable，and the integrity of the purse must be maintained throughout the entire procedure.