Rectal cancer is one of the most common malignant tumors in China, among which middle and lower rectal cancer is the most common. Traditional surgery requires permanent abdominal wall stoma, and although the tumor is radically cured, the postoperative survival quality is seriously reduced. With the advancement of mechanical suture technology and continuous improvement of surgical methods, the goal of rectal cancer surgical treatment has shifted to radical treatment and improvement of postoperative survival quality taking into account total mesorectalexcision (TME) and double stapling technique (DST), so that the technique of anus-preserving surgery for low rectal cancer has matured and been rapidly promoted in recent years. With the improvement of anastomosis technique and the wide application of double-stapling technique (DST), a considerable number of patients with low rectal cancer have been able to undergo anus-preserving surgery and have obtained good curative effect. The introduction of the double-stapling technique has improved the success rate of intrapelvic low-level anastomosis and expanded the scope of anus preservation. Surgical instruments We routinely use the domestic Changzhou New Energy 45mm closure device and 29mm anastomosis clutch, and in a few patients, we use the US Johnson & Johnson articulated head linear closure device (PR0XIMUlTE Access 55) Surgical operation Following the operating principles of total mesorectal excision (TME) and pelvic autonomic nerve preservation, we sharply and completely separate the rectal segment where the tumor is located and the rectal mesentery to the level of the anal levator muscle, and cut off the tumor more than 10cm from the upper edge of the tumor. The tumor was cut off more than 10 cm from the upper edge of the tumor, and a cutter closure (curved closure or articulated head linear closure) was placed below the tumor at a point sufficient to cut the edge (1.5-3.0 cm), and the cutter closure was removed and the specimen was sent for pathological examination. In the proximal colon, a purse-string suture is made with a purse-string clamp, and an anastomotic staple holder is placed and the purse-string is tightened; after dilating the anus, a round bent tube anastomosis is placed in the anus to the distal rectal closure end, and the tip is screwed out in front of the linear closure end, and the linear anastomotic staple is sewn around the central joint rod and folded into the anastomotic resection area, and then after the proximal colon staple holder is joined to the anastomosis, the safety is opened and the firing is performed, and a The “click” sound indicates the completion of cutting and anastomosis. The proximal and distal anastomotic rings were checked for integrity. Surgical efficacy All 35 of our patients had successful rectal closure and anastomosis, and no cancer cell infiltration was seen on postoperative cut margin pathology. 2 cases (5.7%) of postoperative anastomotic leak occurred, which were cured by conservative treatment, and there were no perioperative death cases. There was no anastomotic stenosis. The patients had (5-8)/d stools in the early postoperative period and (2-3)/d after 3 months. 35 cases were followed up for 3 to 60 months, with an average of 20 months. There was one case of pelvic recurrence (2.8%) and one case of extensive abdominal metastasis (2.8%). In recent years, bulk case studies have shown that the lymphatic spread of rectal cancer below the peritoneal fold is mainly to the upper part, and only when there is cancer embolus in the lymphatic vessels above the highly malignant or advanced cancer foci does it reverse to the lower part, and the safe distance of the lower incisional margin of rectal cancer is 2 cm. The invention of surgical sutures is of great significance in the history of modern surgical development, as it has mechanized surgery and saved operating time. In China, the double anastomosis method was applied to rectal cancer anus-preserving surgery until the 1990s. The use of double anastomosis technique provides surgeons with the convenience of closing the rectal stump in a narrow and deep space, making the operation easy for patients with low rectal cancer or obese and fit patients with small pelvis, and it can be closer to the anal side, with a simple and reliable method, exceeding the limit of low anastomosis of rectal cancer before resection maneuver and expanding the scope of anus-preserving surgery. Moreover, the anastomosis is firm and of the same caliber size, so that anastomotic leakage and stenosis are not easy to occur, which can shorten the operation time and the patient recovers quickly after the operation. The reported incidence of anastomotic fistula with double anastomosis-preserving surgery is 2. 5% – 5. 0% with postoperative drainage placement, anal dilation, and placement of anal canal drainage to facilitate decompression. Usually postoperative anastomotic fistulas are successfully treated conservatively. Our hospital has gained a lot of clinical experience in gastrointestinal anastomosis since the use of the anastomosis clutch in the 1980s. Since the 1990s, most of the anastomoses have been performed with disposable anastomoses, making the anastomosis more reliable. In 2008, we won the Second Prize of Science and Technology Progress of Maanshan Health Bureau for “Clinical application of ultra-low resection of middle and lower rectal cancer”. In recent years, based on the extensive use of anastomosis, we have carried out the application of double anastomosis for total rectal mesenteric resection in middle and lower rectal cancer and achieved satisfactory results.