Rectal cancer is one of the common malignant tumors in China, accounting for 60%-70% of all colorectal tumors, and low rectal cancer below the peritoneal reflex accounts for about 70%-75% of rectal cancer. Since the 1990s, the double anastomosis technique has been widely used, making the anus preservation rate of low rectal cancer reach about 70% and becoming the preferred procedure for radical surgery of low rectal cancer. The authors retrospectively analyzed 43 cases of anus preservation in low rectal cancer with double anastomosis technique since 2000 and reported as follows.
Clinical data
1.General information
There were 43 cases in the group, 29 males and 14 females, aged from 37 to 72 years old, with an average of 51.3 years old. The distance of the tumor from the anal verge was measured by preoperative anal diagnosis, 5cm-7cm in 11 cases and 7cm-10cm in 32 cases. Clinicopathological staging, Dukes stage B in 19 cases and stage C in 24 cases. The tumor histological staging, 12 cases of highly differentiated adenocarcinoma, 22 cases of moderately differentiated adenocarcinoma, and 9 cases of poorly differentiated adenocarcinoma.
2.Surgical methods
According to the principle of total mesenteric excision of rectum (TME), the rectum was fully freed, the intestinal cavity was flushed with saline containing anti-cancer drugs, and a linear closure device was applied to close the distal rectum at 2 cm to 3 cm distal to the tumor to remove the tumor; since the rectum could extend upward about 3 cm to 4 cm after being freed from the presacral area, the distal rectum was successfully closed in all cases by adjusting the angle and placement direction of the closure device. In all cases, the distal rectal closure was successfully completed by adjusting the angle and placement direction of the closure device.
The proximal colon should be fully freed so that the anastomosis can be tension-free and end-to-end anastomosis with the distal rectum can be performed; during the operation, it should be noted that the base of the anastomosis should be gently placed after full anal dilation, and rough operation is prohibited to prevent tearing of the mucosa and muscle layer of the stump rectum. After the anastomosis is completed, the cutting ring should be routinely checked for completeness, and the anastomosis can be gently checked for completeness with a finger through the anus. After the operation, a thick anal tube is routinely placed through the anus, and the proximal end is placed through the anastomosis into the descending colon, which is removed 3 to 5 days after the operation.
3. Results
The surgical procedure was smooth in all the cases, and 5 cases of anastomotic leak were found intraoperatively, which were repaired by manual suturing; there was no surgical death, no anastomotic leak or anastomotic bleeding; 2 cases of anastomotic stenosis had no difficulty in defecation after anal dilatation; 2 cases without anastomotic stenosis had difficulty in defecation, which were considered to be due to pelvic plexus injury, resulting in intestinal motor dysfunction, and the symptoms were gradually improved by conservative treatment measures such as enema and oral medication; about 80% About 80% of the cases had different degrees of stool frequency, urgency and incomplete stool symptoms after surgery, which were gradually relieved after a period of adaptation (1 month to 6 months).
Discussion
Low rectal cancer refers to rectal cancer located below the peritoneal fold, including rectal tumors between the peritoneal fold and the dentate line, which is more difficult to operate because the tumor is located in the pelvis and close to the anal side. However, the operation requires a permanent colostomy (commonly known as an artificial anus) in the abdomen at the same time, which causes a burden on the patient’s mind, difficulties and inconveniences in life.
In order to improve the quality of life of patients after surgery, people have been seeking various types of anal preservation surgery to preserve the anus. Anal preservation surgery in the strict sense should refer to the preservation of sound defecation control functions, including good sphincter function, intact anal canal skin, acute and discriminatory defecation, exhaust function, and certain fecal storage functions, not formally maintaining defecation from the perineum, therefore, various types of sphincter formation or Therefore, all kinds of sphincter formation or in situ anal reconstruction should not be the scope of anal preservation.
In recent years, due to theoretical and practical confirmation of the rationality and feasibility of anal preservation surgery for low rectal cancer, coupled with the improvement of surgical techniques and continuous improvement and development of surgical instruments, anal preservation surgery for rectal cancer has increased from about 40% in the past to about 70% at present, especially the introduction of double anastomosis technology in the 1990s, which can be said to be epoch-making for anal preservation surgery for rectal cancer.
Compared with manual suture, double anastomosis technique is more possible and safe when dealing with distal rectum, low or ultra-low resection, which makes the surgery almost impossible to be completed by manual suture fast and safe; the application of double anastomosis technique can not only improve the rate of anal preservation, but also significantly reduce the incidence of anastomotic fistula, according to the data, the incidence of anastomotic fistula can be reduced to between 2,5% and 5%, which is much lower than the 10% of traditional manual suture. It is reported that the incidence of anastomotic fistula can be reduced to 2,5%-5%, which is much lower than the 10% of traditional manual suture; compared with manual suture.
The application of the double anastomosis technique also has the following advantages.
(1) By rotating the head of the obturator and adjusting the angle, the tumor can be removed and the distal rectum can be closed as close to the anal side as possible to achieve a lower position of anastomosis, especially in male, obese, and pelvic stenosis patients. (2) One-time closure of the distal rectum reduces contamination during open suturing.
(3) Reduction of wrinkling and overlapping of the intestinal wall during manual suturing, especially when suturing a wide rectal pot belly, effectively preventing potential factors causing anastomotic fistula.
(4) The one-time stapling of double B-type anastomotic staples results in more uniform force on the anastomosis and neater mucosal alignment, reducing the occurrence of complications such as anastomotic leakage, bleeding, and stenosis.
Although, there are many advantages in the application of double anastomosis technique in low rectal cancer, but improper application may still lead to complications and even surgical failure in the application process.
Great attention should be paid to the following issues.
(1) Apply anti-cancer drugs to flush the intestinal cavity before anastomosis to prevent tumor cell implantation.
(2) Remove connective tissue and ligament of the stump as much as possible to prevent complications such as over-thickness of tissue and incomplete stapling and bleeding.
(3) Never use violence to prevent tearing of the anastomosis, mucosa and muscle layer of the rectal stump.
(4) Before anastomosis (closure), carefully check whether other tissues are clamped to prevent damage to adjacent tissues and organs.
(5) Select instruments of appropriate caliber, be familiar with the operation of the instruments, and ensure good performance of the instruments.
In conclusion, double anastomosis technique is an advanced surgical technique, the application of which can complete low or ultra-low anastomosis which is difficult to do by manual operation and increase the chance of anal preservation for patients with low rectal cancer, but improper operation may still cause many complications and bring harm to patients. Therefore, the correct use of double anastomosis technique can not only improve the rate of anus preservation for low rectal cancer, avoid unnecessary anal resection, improve the postoperative quality of life, but also ensure the radicality of the operation and obtain a good survival rate.